U.S. patent application number 14/777118 was filed with the patent office on 2016-02-11 for artificial environment for efficient uptate of fertilizers and other agrochemicals in soil.
This patent application is currently assigned to ADAMA MAKHTESHIM LTD.. The applicant listed for this patent is Matti BEN-MOSHE, Eran SEGAL, Uri SHANI, Asher VITNER. Invention is credited to Matti BEN-MOSHE, Eran SEGAL, Uri SHANI, Asher VITNER.
Application Number | 20160037728 14/777118 |
Document ID | / |
Family ID | 51520826 |
Filed Date | 2016-02-11 |
United States Patent
Application |
20160037728 |
Kind Code |
A1 |
SHANI; Uri ; et al. |
February 11, 2016 |
ARTIFICIAL ENVIRONMENT FOR EFFICIENT UPTATE OF FERTILIZERS AND
OTHER AGROCHEMICALS IN SOIL
Abstract
A unit for delivery of agrochemicals to the roots of a plant
comprising one or more root development zones, and one or more
agrochemical zones containing at least one agrochemical, wherein
the agrochemical zones are formulated to release the at least one
agrochemical into the root development zones in a controlled
release manner when the root development zones are hydrated, and
wherein the weight ratio of the root development zones to the
agrochemical zones in a dry unit is 0.05:1 to 0.32:1.
Inventors: |
SHANI; Uri; (Ness-Ziona,
IR) ; VITNER; Asher; (Jerusalem, IR) ;
BEN-MOSHE; Matti; (Reut, IR) ; SEGAL; Eran;
(Kibbutz-Hulda, US) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHANI; Uri
VITNER; Asher
BEN-MOSHE; Matti
SEGAL; Eran |
Ness-ziona
Jerusalem
Reut
Kibbutz-hulda |
|
IL
IL
IL
IL |
|
|
Assignee: |
ADAMA MAKHTESHIM LTD.
Beer Sheva
IR
|
Family ID: |
51520826 |
Appl. No.: |
14/777118 |
Filed: |
March 14, 2014 |
PCT Filed: |
March 14, 2014 |
PCT NO: |
PCT/IB2014/001194 |
371 Date: |
September 15, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61793697 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
47/48.5 |
Current CPC
Class: |
A01N 25/04 20130101;
A01G 22/00 20180201; A01N 25/26 20130101; C05G 3/80 20200201; C05G
5/37 20200201 |
International
Class: |
A01G 1/00 20060101
A01G001/00; A01N 25/04 20060101 A01N025/04 |
Claims
1. A unit for delivery of agrochemicals to the roots of a plant
comprising: i) one or more root development zones, and ii) one or
more agrochemical zones containing at least one agrochemical,
wherein the agrochemical zones are formulated to release the at
least one agrochemical into the root development zones in a
controlled release manner when the root development zones are
swelled, and wherein the weight ratio of the root development zones
to the agrochemical zones in a dry unit is 0.05:1 to 0.32:1 or
wherein the total volume of the root development zones in the unit
is at least 0.2 mL when the unit is fully swelled.
2. (canceled)
3. (canceled)
4. (canceled)
5. The unit of claim 1, wherein the weight ratio of the root
developments zones to agrochemical zones in a dry unit is 0.05:1,
0.1:1, 0.15:1, 0.2:1, 0.25:1, or 0.3:1.
6. The unit of claim 5, wherein the total volume of the root
development zones in the unit is at least at least 0.2 mL, at least
0.5 mL, at least 1 mL, at least 2 mL, at least 5 mL, at least 10
mL, at least 20 mL, at least 30 mL, at least 40 mL, at least 50 mL,
at least 60 mL, at least 70 mL, at least 80 mL, at least, 90 mL, at
least 100 mL, at least 150 mL, at least 200 mL, at least 250 mL, at
least 300 mL, at least 350 mL, at least 400 mL, at least 450 mL, at
least 500 mL, at least 550 mL, at least 600 mL or larger than 600
mL when the unit is fully swelled.
7. (canceled)
8. (canceled)
9. The unit of claim 5, wherein roots of a plant are capable of
growing within the root development zones when the root development
zones are swelled, and wherein the total volume of the root
development zones when the unit is 1%-100% swelled is large enough
to contain at least 10 mm of a root having a diameter of 0.5
mm.
10. (canceled)
11. The unit of claim 1, wherein the unit has a dry weight of 0.1 g
to 20 g and wherein the total weight of the agrochemical zones of
the unit is 0.05 to 5 grams.
12. (canceled)
13. The unit of claim 1, wherein the unit is in the shape of a
cylinder, polyhedron, cube, disc, or sphere.
14. (canceled)
15. (canceled)
16. (canceled)
17. (canceled)
18. The unit of claim 1, wherein the agrochemical zones and the
root development zones are adjoined, or wherein the agrochemical
zones are partially contained within the root development zones
such that the surface of the unit is formed by both the root
development zones and the agrochemical zones.
19. (canceled)
20. The unit of claim 18, wherein the unit is a bead comprising an
external zone surrounding an internal zone, wherein the root
development zones form the external zone and the agrochemical zones
form the internal zone.
21. The unit of claim 20, wherein the unit comprises one root
development zone and one agrochemical zone.
22. The unit of claim 21, wherein the root development zones
comprise a super absorbent polymer (SAP).
23. The unit of claim 22, wherein the root development zones are
capable of absorbing at least about 10, 15, 20, 25, 30, 35, 40, 45,
50, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, or 1000 times
their weight in water.
24. The unit of claim 23, wherein the root development zones are
permeable to oxygen, or wherein the root development zones comprise
an aerogel, a hydrogel or an organogel, or wherein the root
development zones further comprise a polymer, a porous inorganic
material, a porous organic material, or any combination
thereof.
25. (canceled)
26. (canceled)
27. (canceled)
28. (canceled)
29. (canceled)
30. The unit of claim 20, wherein the agrochemical zones further
comprise an aerogel, a hydrogel, an organogel, a polymer, a porous
inorganic material, a porous organic material, or any combination
thereof.
31. (canceled)
32. (canceled)
33. (canceled)
34. (canceled)
35. (canceled)
36. (canceled)
37. (canceled)
38. (canceled)
39. (canceled)
40. The unit of claim 30, wherein the root development zones
comprise a synthetic hydrogel, a natural carbohydrate hydrogel, or
a pectin or protein hydrogel, or any combination thereof.
41. The unit of claim 40, wherein the root development zones
comprise a natural super absorbent polymer (SAP), a poly-sugar SAP,
a semi-synthetic SAP, a fully-synthetic SAP, or any combination
thereof, or wherein the root development zones further comprise at
least one oxygen carrier that increases the amount of oxygen in the
root development zones compared to corresponding root development
zones not comprising the oxygen carrier.
42. (canceled)
43. The unit of claim 41, wherein the agrochemical zones comprise
an organic polymer, a natural polymer, or an inorganic polymer, or
any combination thereof.
44. The unit of claim 1, wherein the agrochemical zones are
partially or fully coated with a coating system that dissolves into
the root development zones when the root development zones are
swelled and slows the rate at which the at least one agrochemical
dissolves into the root development zones when the root development
zones are swelled.
45. (canceled)
46. (canceled)
47. (canceled)
48. The unit of claim 1, wherein the at least one agrochemical is:
i) at least one fertilizer compound; ii) at least one pesticide
compound, iii) at least one hormone compound; iv) at least one drug
compound; v) at least one chemical growth agents; vi) at least one
enzyme; vii) at least one growth promoter; and/or viii) at least
one microelement.
49. A method of growing a plant, comprising adding at least one
unit of claim 1 to the medium in which the plant is grown.
50. (canceled)
51. (canceled)
52. A method of generating an artificial zone with predetermined
chemical properties within the root zone of a plant, comprising: i)
adding one or more units to the root zone of the plant; or ii)
adding one or more units to the anticipated root zone of the medium
in which the plant is anticipated to grow, wherein at least one of
the one or more units is as defined in claim 1.
Description
[0001] This application claims priority of U.S. Provisional
Application No. 61/793,697, filed Mar. 15, 2013, the content of
which is hereby incorporated by reference in its entirety.
[0002] Throughout this application, various publications are
referenced, including referenced in parenthesis. Full citations for
publications referenced in parenthesis may be found listed at the
end of the specification immediately preceding the claims. The
disclosures of all referenced publications in their entireties are
hereby incorporated by reference into this application in order to
more fully describe the state of the art to which this invention
pertains.
BACKGROUND OF INVENTION
[0003] Current practices and technologies yield poor agrochemical
use efficiency by plants due to over application (up to 50%)
(Shaviv and Mikkelsen 1993). Excessive application of agrochemicals
has adverse effects on the environment and is costly for farmers
(Shaviv and Mikkelsen 1993). Additionally, many soils and climates
are not suitable for growing crops (Habarurema and Steiner, 1997;
Nicholson and Farrar, 1994).
[0004] New practices and technologies are needed for efficient
application of fertilizers and other agrochemicals for improving
plant growth.
SUMMARY OF THE INVENTION
[0005] The invention provides a unit for delivery of agrochemicals
to the roots of a plant comprising: [0006] i) one or more root
development zones, and [0007] ii) one or more agrochemical zones
containing at least one agrochemical, [0008] wherein the
agrochemical zones are formulated to release the at least one
agrochemical into the root development zones in a controlled
release manner when the root development zones are swelled, and
[0009] wherein the weight ratio of the root development zones to
the agrochemical zones in a dry unit is 0.05:1 to 0.32:1.
[0010] The invention provides a unit for delivery of agrochemicals
to the roots of a plant comprising: [0011] i) one or more root
development zones, and [0012] ii) one or more agrochemical zones
containing at least one agrochemical, [0013] wherein the
agrochemical zones are formulated to release the at least one
agrochemical into the root development zones in a controlled
release manner when the root development zones are swelled, and
[0014] wherein the total volume of the root development zones in
the unit is at least 0.2 mL when the unit is fully swelled.
[0015] The invention provides a method of growing a plant,
comprising adding at least one unit of the invention to the medium
in which the plant is grown.
[0016] The invention provides a method of reducing environmental
damage caused by an agrochemical, comprising delivering the
agrochemical to the root of a plant by adding at least one unit of
the invention to the medium of the plant.
[0017] The present invention provides a method of minimizing
exposure to an agrochemical, comprising delivering the agrochemical
to the root of a plant by adding at least one unit of the invention
to the medium of the plant.
[0018] The present invention provides a method of generating an
artificial zone with predetermined chemical properties within the
root zone of a plant, comprising: [0019] i) adding one or more
units of the invention to the root zone of the plant; or [0020] ii)
adding at one or more units of the invention to the anticipated
root zone of the medium in which the plant is anticipated to
grow.
[0021] The present invention provides a method of increasing the
growth rate of a plant, comprising (i) adding one or more units of
the invention to a medium where the plant is growing or is to be
grown, and (ii) growing the plant, wherein the plant grows faster
in the medium containing the units than in the medium not
containing the units.
[0022] The present invention provides a method of increasing the
size of a plant, comprising (i) adding one or more units of the
invention to a medium where the plant is growing or is to be grown,
and (ii) growing the plant, wherein the plant grows larger in the
medium containing the units than in the medium not containing the
units.
[0023] The present invention provides a method of increasing N, P,
K, and/or micronutrient (e.g. Zn, Fe, Cu) uptake by a plant,
comprising (i) adding one or more units of the invention to a
medium where the plant is growing or is to be grown, and (ii)
growing the plant, wherein the N, P, and/or K uptake of the plant
is greater in the medium containing the units than in the medium
not containing the units.
[0024] The present invention provides a method of protecting a
plant from low ambient temperatures, comprising (i) adding one or
more units of the invention to a medium where the plant is growing
or is to be grown, and (ii) growing the plant, wherein plants grown
in the medium containing the units have greater survival rates
under low ambient temperatures than plants grown in the medium not
containing the units.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1. Swelling behavior of semi-synthetic hydrated SAPs
following hydration and rehydration cycles in water.
[0026] FIG. 2. Swelling behavior of hydrated SAPs following
hydration and rehydration cycles in sandy soil.
[0027] FIG. 3. Swelling behavior of hydrated SAPs following
hydration and rehydration cycles in sandy soil loose soil.
[0028] FIG. 4. Dissolved oxygen level in the water reservoir
opposite the oxygen saturated water.
[0029] FIG. 5. Silica coating process on poly sugar beads.
[0030] FIG. 6. Beehive like structure made by the Bentonite
filler.
[0031] FIG. 7. Schematic illustration of the hybrid encapsulation
method.
[0032] FIG. 8. Release of nitrate from internal zone without (left
bars) and with (right bars) Silica coating.
[0033] FIG. 9. Release of PO.sub.4 from internal zone incorporated
with Bentonite filler over time.
[0034] FIG. 10A-G. (A) Pea roots growth in CMC--Lab. (B) Corn roots
growth in Alginate--Lab. (C) Pea root growth in k-Carrageenan--Lab.
(D) Pea root growth on CMC--Lab. (E) Corn root grown in Fully
synthetic--Lab. (F) Corn root grown in Fully synthetic--Lab. (G)
Corn roots growth in Alginate--Lab.
[0035] FIG. 11. Phase 1: Banding and incorporating dry "beads",
made from an external zone (hydrogel) and internal zone (coated
minerals) into the upper soil profile. Phase 2: Following watering,
the beads swell (up to, e.g., 5 cm in diameter) and agrochemicals
diffuse to the external zone & soil. Phase 3: Roots grow and
are sustained in/near the external zone, and uptake lasts a few
weeks (6-8).
[0036] FIG. 12. Non-limiting examples of bead content and
dimensions.
[0037] FIG. 13. Dissolved Oxygen System.
[0038] FIG. 14. The field plot experimental setup of Example 3.
[0039] FIG. 15. Soil temperatures at the experimental site of
Example 3. Top line shows maximum soil temperatures and bottom line
shows minimum soil temperatures.
[0040] FIG. 16. Relative weight of the hydrogels and water
application over time in Example 3.
[0041] FIG. 17. Final surface areas of the hydrogel units of
Example 3.
[0042] FIG. 18. Surface areas of the hydrogel units of Example 3
over time.
[0043] FIG. 19. Final surface area to volume ratio of the hydrogel
units of Example 3.
[0044] FIG. 20. Final minimal distance values of the hydrogel units
of Example 3.
[0045] FIG. 21. Minimal distance of the hydrogel units of Example 3
versus time.
[0046] FIG. 22. Final stiffness values of the hydrogel units of
Example 3.
[0047] FIG. 23. Stiffness of the hydrogel units of Example 3 versus
time.
[0048] FIG. 24A-I. Photos of the hydrogels of Example 3 from plots
A-C at the end of the experiment. FIG. 24A: fully synthetic; FIG.
24B: Semisynthetic CMC 6% AAm; FIG. 24C: Semisynthetic CMC 6% AA;
FIG. 24D: Semisynthetic CMC 25% AA; FIG. 24E: Semisynthetic CMC 50%
AA; FIG. 24F: Polysugars Alginate; FIG. 24G: Semisynthetic CMC 6%
AAm-Large; FIG. 24H: Semisynthetic CMC 50% AA-large; FIG. 24I:
Semisynthetic CMC 6% AAm-Small.
[0049] FIG. 25A-I. Photos of the hydrogels of Example 3 from plot D
at the end of the experiment. Left panels of FIGS. 25A-G show
hydrogels in situ. Right panels of FIGS. 25A-G show samples where
roots penetrated through the hydrogel. FIG. 25A: fully synthetic;
FIG. 25B: Semisynthetic CMC 6% AAm; FIG. 25C: Semisynthetic CMC 6%
AA; FIG. 25D: Semisynthetic CMC 25% AA; FIG. 25E: Semisynthetic CMC
50% AA; FIG. 25F: Semisynthetic CMC 6% AAm-Large; FIG. 25G:
Semisynthetic CMC 50% AAm-Large; FIG. 25H: Semisynthetic CMC 25%
AA; FIG. 25I: Semisynthetic CMC 6% AAm-Large.
[0050] FIG. 26. Twenty three rotated weighing lysimeters used in
Example 4.
[0051] FIG. 27A-B. Dehydrated cylindrical shape fertilizer units of
Example 4 prior to application (FIG. 27A) and partly hydrated
fertilizer units at application (FIG. 27B).
[0052] FIG. 28. Application dose of N, P, and K per plant for each
treatment of Example 4, stage 1. Slow release: left bars;
fertilizer units (Full): middle bars; fertilizer units (Half):
right bars.
[0053] FIG. 29A-C. Plant height (FIG. 29A), number of leaves (FIG.
29B), and SPAD values (FIG. 29C) of the plants of Example 4, stage
1.
[0054] FIG. 30A-C. Plant dry matter (FIG. 30A), absolute NPK uptake
amount (FIG. 30B), and NPK uptake efficiency (FIG. 30C) of the
plants of Example 4, stage 1. Fertilizer units (Full): left bars;
Fertilizer units (Half): middle bars; Slow release: right bars.
[0055] FIG. 31. Relative residuals of N, P, and K in the fertilizer
units following harvest of the plants of Example 4, stage 1.
Fertilizer units (Full): left bars; Fertilizer units (Half): right
bars.
[0056] FIG. 32A-D. Plant height (FIG. 32A), number of leaves (FIG.
32B), SPAD values (FIG. 32C), and wet biomass (FIG. 32D) for plants
of stage 2 of Example 4 grown in sandy soil. FIG. 32D: left bars
show data for empty units plus fertigation (Full) and right bars
show data for fertilizer units (Full).
[0057] FIG. 33A-D. Plant height (FIG. 33A), number of leaves (FIG.
33B), SPAD values (FIG. 33C), and wet biomass (FIG. 33D) for plants
of stage 3 of Example 4 grown in Growing Media. FIG. 33D: left bars
show data for SR, middle bars show data for fertilizer units, and
right bars show data for fertigation.
[0058] FIG. 34A-D. Plant height (FIG. 34A), number of leaves (FIG.
34B), SPAD values (FIG. 34C), and wet biomass (FIG. 34D) for plants
of stage 3 of Example 4 grown in clayey Media. FIG. 34D: left bars
show data for fertilizer units and right bars show data for SR.
[0059] FIG. 35A-Q. Photos of fertilizer units and plants at the end
of Example 4. FIG. 35A: hydrated fertilizer unit; FIG. 35B: root
penetration inside hydrated fertilizer unit; FIG. 35C: root
distribution within hydrated fertilizer unit; FIG. 35D: root
distribution within hydrated fertilizer unit; FIG. 35E: stage 1
fertilizer unit (full); FIG. 35F: stage 1 fertilizer unit (half);
FIG. 35G: stage 1 SR (full); FIG. 35H: fertilizer unit full
(right), fertilizer unit half (left) and SR (middle); FIG. 35I:
stage 2 fertilizer unit (full); FIG. 35J: stage 2 fertilizer unit
(full); FIG. 35K: stage 2 empty unit plus fert.; FIG. 35L: stage 2
empty unit plus fert.; FIG. 35M: stage 3 growing media and
fertilizer unit; FIG. 35N: stage 3 growing media and SR; FIG. 35O:
stage 3 growing media and fert.; FIG. 35P: stage 3 clay and
fertilizer unit; FIG. 35Q: stage 3 clay and SR.
[0060] FIG. 36. Plot design of Example 5.
[0061] FIG. 37A-E. Measured parameters throughout the growing
season for plants of Example 5. FIG. 37A: sunflower height; FIG.
37B: sunflower number of leaves; FIG. 37C: sunflower chlorophyll
content optical sensor-SPAD values; FIG. 37D: cabbage leaves
diameter; FIG. 37E: cabbage number of leaves.
[0062] FIG. 38A-B. Macro-nutrient (N, P, and K) content in
sunflower and cabbage leaves of Example 5. Left bars show data for
fertilizer units, middle bars show data for SR, and right bars show
data for fertigation.
[0063] FIG. 39A-B. FIG. 39A: ratio between cabbage head diameter
and weight in cabbage plants of Example 5; FIG. 39B: calculated
cabbage head weight over the growing season of Example 5.
[0064] FIG. 40. Cabbage dry matter and N-uptake in the cabbage
plants of Example 5. FIG. 40A: final cabbage dry matter per plant
in three subplots; FIG. 40B: cabbage nitrogen uptake per plant in
three subplots. Left bars show data for fertilizer units, middle
bars show data for SR, and right bars show data for
Fertigation.
[0065] FIG. 41. Sunflower grain yield and nitrogen uptake per meter
in the 3 subplots of Example 5. Left bars show data for fertilizer
units, middle bars show data for SR, and right bars show data for
fertigation.
[0066] FIG. 42. NPK residuals in fertilizer units for each plot and
crop of Example 5; FIG. 42A: cabbage; FIG. 42B: sunflower. Left
bars show data for plot 1, middle bars show data for plot 2, and
right bars show data for plot 3.
[0067] FIG. 43. Final N soil content in the root zone (>30 cm)
for each crop of Example 5. Left bars show data for sunflower and
right bars show data for cabbage.
[0068] FIG. 44A-H. Calculated N mass balance in the root zone of
cabbage and sunflower plots of Example 5. FIG. 44A: fertilizer
unit, SR, and Fert initial N mass balance for cabbage plots; FIG.
44B: fertilizer unit final N balance for cabbage plots; FIG. 44C:
SR final N balance for cabbage plots; FIG. 44D: Fert final N
balance for cabbage plots; FIG. 44E: fertilizer unit, SR, and Fert
initial N mass balance for sunflower plots; FIG. 44F: fertilizer
unit final N balance for sunflower plots; FIG. 44G: SR final N
balance for sunflower plots; FIG. 44H: Fert final N balance for
sunflower plots.
[0069] FIG. 45A-C. Photographs showing the hydrated fertilizer
units of Example 5. FIG. 45A: hydrated fertilizer unit; FIG. 45B:
root distribution around hydrated fertilizer units; FIG. 45C: Root
penetration inside hydrated fertilizer unit.
[0070] FIG. 46. Fertilizer units made according to the process of
Example 6.
[0071] FIG. 47. A fully swelled fertilizer unit made according to
the process of Example 6 compared to a dried fertilizer unit made
according to the process of Example 6.
[0072] FIG. 48. Combined marketable yield of lettuce and celery
from the crops of Example 8 fertilized with fertilizer units or
solid fertilizer.
DETAILED DESCRIPTION OF THE INVENTION
[0073] The invention provides a unit for delivery of agrochemicals
to the roots of a plant comprising: [0074] i) one or more root
development zones, and [0075] ii) one or more agrochemical zones
containing at least one agrochemical, [0076] wherein the
agrochemical zones are formulated to release the at least one
agrochemical into the root development zones in a controlled
release manner when the root development zones are swelled, and
[0077] wherein the weight ratio of the root development zones to
the agrochemical zones in a dry unit is 0.05:1 to 0.32:1.
[0078] In some embodiments, the total volume of the root
development zones in the unit is at least 0.2 mL when the unit is
fully swelled.
[0079] The invention provides a unit for delivery of agrochemicals
to the roots of a plant comprising: [0080] i) one or more root
development zones, and [0081] ii) one or more agrochemical zones
containing at least one agrochemical, [0082] wherein the
agrochemical zones are formulated to release the at least one
agrochemical into the root development zones in a controlled
release manner when the root development zones are swelled, and
[0083] wherein the total volume of the root development zones in
the unit is at least 0.2 mL when the unit is fully swelled.
[0084] In some embodiments, the weight ratio of the root
development zones to the agrochemical zones in a dry unit is 0.05:1
to 0.32:1.
[0085] In some embodiments, the weight ratio of the root
development zones to the agrochemical zones in a dry unit is
0.05:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, or 0.3:1.
[0086] In some embodiments, the weight ratio of the root
development zones to the agrochemical zones in a dry unit is 0.01:1
to 0.5:1, 0.01:1 to 0.02:1, 0.01:1 to 0.03:1, 0.01:1 to 0.04:1,
0.01:1 to 0.05:1, 0.3:1 to 0.4:1, 0.3:1 to 0.4:1, 0.3:1 to
0.5:1.
[0087] In some embodiments, the total volume of the root
development zones in the unit is at least 0.2 mL, 0.5 mL, at least
1 mL, at least 2 mL, at least 5 mL, at least 10 mL, at least 20 mL,
at least 30 mL, at least 40 mL, at least 50 mL, at least 60 mL, at
least 70 mL, at least 80 mL, at least 90 mL, at least 100 mL, at
least 150 mL, at least 200 mL, at least 250 mL, at least 300 mL, at
least 350 mL, at least 400 mL, at least 450 mL, at least 500 mL, at
least 550 mL, at least 600 mL or larger than 600 mL when the unit
is 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50%, or
5-50% swelled.
[0088] In some embodiments, the total volume of the root
development zones in the unit is at least 2 mL when the unit is 1%,
5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50%, or 5-50%
swelled.
[0089] In some embodiments, the total volume of the root
development zones in the unit is greater than 2 mL, 2-3 mL, 3-4 mL,
4-5 mL, 2-5 mL, 2-10 mL, 5-10 mL, 5-20 mL, 10-15 mL, 10-20 mL,
15-20 mL, 10-40 mL, 20-40 mL, 20-80 mL, 40-80 mL, 50-100 mL, 75-150
mL, 100-150 mL, 150-300 mL, 200-400 mL, 300-600 mL, or 600-1000 mL
when the unit is 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%,
50%, 1-50%, or 5-50% swelled.
[0090] In some embodiments, the total volume of the root
development zones in the unit is at least 0.2 mL, at least 0.5 mL,
at least 1 mL, at least 2 mL, at least 5 mL, at least 10 mL, at
least 20 mL, at least 30 mL, at least 40 mL, at least 50 mL, at
least 60 mL, at least 70 mL, at least 80 mL, at least 90 mL, at
least 100 mL, at least 150 mL, at least 200 mL, at least 250 mL, at
least 300 mL, at least 350 mL, at least 400 mL, at least 450 mL, at
least 500 mL, at least 550 mL, at least 600 mL or larger than 600
mL when the unit is fully swelled.
[0091] In some embodiments, the total volume of the root
development zones in the unit is at least 2 mL when the unit is
fully swelled.
[0092] In some embodiments, the total volume of the root
development zones in the unit is greater than 2 mL, 2-3 mL, 3-4 mL,
4-5 mL, 2-5 mL, 2-10 mL, 5-10 mL, 5-20 mL, 10-15 mL, 10-20 mL,
15-20 mL, 10-40 mL, 20-40 mL, 20-80 mL, 40-80 mL, 50-100 mL, 75-150
mL, 100-150 mL, 150-300 mL, 200-400 mL, 300-600 mL, or 600-1000 mL
when the unit is fully swelled.
[0093] In some embodiments, the total volume of the root
development zones when the unit is 1%-100% swelled is large enough
to contain at least 10 mm of a root having a diameter of 0.5
mm.
[0094] In some embodiments, the total volume of the root
development zones when the unit is 1-100% swelled is large enough
to contain 10-50 mm of a root having a diameter of 0.5-5 mm.
[0095] In some embodiments, the total volume of the root
development zones when the unit is 1%, 5%, 10%, 15%, 20%, 25%, 30%,
35%, 40%, 45%, 50%, 1-50%, or 5-50% swelled is large enough to
contain at least 10 mm of a root having a diameter of 0.5 mm.
[0096] In some embodiments, the total volume of the root
development zones when the unit is 1%, 5%, 10%, 15%, 20%, 25%, 30%,
35%, 40%, 45%, 50%, 1-50% or 5-50% swelled is large enough to
contain 10-50 mm of a root having a diameter of 0.5-5 mm.
[0097] In some embodiments, the unit has a dry weight of 0.1 g to
20 g.
[0098] In some embodiments weight of the dry unit is 1-10 g. In
some embodiments, the weight of the dry unit is 1, 2, 3, 4, 5, 6,
7, 8, 9, or 10 g.
[0099] In some embodiments, the total weight of the agrochemical
zones of the unit is 0.05 to 5 grams.
[0100] In some embodiments, the unit is in the shape of a
cylinder.
[0101] In some embodiments, the unit is in the shape of a
polyhedron.
[0102] In some embodiments, the unit is in the shape of a cube.
[0103] In some embodiments, the unit is in the shape of a disc.
[0104] In some embodiments, the unit is in the shape of a
sphere.
[0105] In some embodiments, the agrochemical zones and the root
development zones are adjoined.
[0106] In some embodiments, the unit consists of one root
development zone which is next to one agrochemical zone.
[0107] In some embodiments, the agrochemical zones are partially
contained within the root development zones such that the surface
of the unit is formed by both the root development zones and the
agrochemical zones.
[0108] In some embodiments, the root development zones are
partially contained within the agrochemical zones such that the
surface of the unit is formed by both the root development zones
and the agrochemical zones.
[0109] In some embodiments, an agrochemical zone is sandwiched
between two root development zones.
[0110] In some embodiments, the agrochemical zone is surrounded by
a root development zone which forms a perimeter around the
agrochemical zone but which covers less than all of the surface of
the agrochemical zone, or vice versa. In some embodiments, the
perimeter is ring shaped.
[0111] In some embodiments, the unit is a bead comprising an
external zone surrounding an internal zone, wherein the root
development zones form the external zone and the agrochemical zones
form the internal zone.
[0112] In some embodiments, the unit comprises one root development
zone and one agrochemical zone.
[0113] In some embodiments, the root development zones comprise a
super absorbent polymer (SAP).
[0114] In some embodiments, the root development zones are capable
of absorbing at least about 10, 15, 20, 25, 30, 35, 40, 45, 50, 75,
80, 85, 90, 95, 100, 200, 300, 400, 500, or 1000 times their weight
in water.
[0115] In some embodiments, the root development zones are capable
of absorbing at least about 20-30 times their weight in water.
[0116] In some embodiments, the root development zones are
permeable to oxygen.
[0117] In some embodiments, the root development zones are
permeable to oxygen such that at least about 6 mg/L of dissolved
oxygen is maintained in the root development zones when the root
development zones are swelled.
[0118] In some embodiments, the root development zones when fully
swelled are at least about 70, 75, 80, 85, 90, 95, or 100% as
permeable to oxygen as swelled alginate or swelled semi-synthetic
CMC.
[0119] In some embodiments, the root development zones comprise an
aerogel, a hydrogel or an organogel.
[0120] In some embodiments, the root development zones comprise a
hydrogel.
[0121] In some embodiments, the root development zones comprise an
aerogel.
[0122] In some embodiments, the root development zones comprise a
geotextile.
[0123] In some embodiments, the root development zones comprise a
sponge.
[0124] In some embodiments, the wherein the root development zones
further comprise a polymer, a porous inorganic material, a porous
organic material, or any combination thereof.
[0125] In some embodiments, the agrochemical zones further comprise
an aerogel, a hydrogel, an organogel, a polymer, a porous inorganic
material, a porous organic material, or any combination
thereof.
[0126] In some embodiments, roots of a plant are capable of
penetrating the root development zones when the root development
zones are about 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%,
50%, 1-50% or 5-50% swelled.
[0127] In some embodiments, roots of a plant are capable of growing
within the root development zones when the root development zones
are swelled.
[0128] In some embodiments, roots of a plant are capable of growing
within the root development zones when the root development zones
are about 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%,
1-50% or 5-50% swelled.
[0129] In some embodiments, microbes are capable of penetrating and
growing within the root development zones when the root development
zones are swelled.
[0130] In some embodiments, the plant is a crop plant.
[0131] In some embodiments, the crop plant is a wheat plant, a
maize plant, a soybean plant, a rice plant, a barley plant, a
cotton plant, a pea plant, a potato plant, a tree crop plant, or a
vegetable plant.
[0132] In some embodiments, the root development zones are capable
of repeated swelling cycles that each comprises hydration followed
by dehydration.
[0133] In some embodiments, the root development zones are capable
of repeated swelling cycles in soil that each comprise hydration
followed by dehydration while in the soil.
[0134] In some embodiments, the unit is in the shape of a sphere or
an equivalent polyhedron.
[0135] In some embodiments, the unit is in the shape of a sphere or
an equivalent polyhedron after repeated swelling cycles.
[0136] In some embodiments, the root development zones, when
swelled, maintain at least about 75%, 80%, 85%, 90%, or 95% of
their water content over a period of at least about 25, 50, 100, or
150 hours in soil.
[0137] In some embodiments, the root development zones, when
swelled, maintain at least about 75%, 80%, 85%, 90%, or 95% of
their water content over a period of at least about 25, 50, 100, or
150 hours in sandy soil.
[0138] In some embodiments, the root development zones, when
swelled, maintain at least about 75%, 80%, 85%, 90%, or 95% of
their volume over a period of at least about 25, 50, 100, or 150
hours in soil.
[0139] In some embodiments, the root development zones, when
swelled, maintain at least about 75%, 80%, 85%, 90%, or 95% of
their volume over a period of at least about 25, 50, 100, or 150
hours in sandy soil.
[0140] In some embodiments, the root development zones, when
swelled, maintain their shape over a period of at least about 25,
50, 100, or 150 hours in soil.
[0141] In some embodiments, the root development zones, when
swelled, maintain their shape over a period of at least about 25,
50, 100, or 150 hours in sandy soil.
[0142] In some embodiments, the root development zones, when
swelled, maintain their shape after repeated swelling cycles that
each comprises hydration followed by dehydration.
[0143] In some embodiments, the root development zones, when
swelled maintain their shape after at least 3 swelling cycles that
each comprises hydration followed by dehydration.
[0144] In some embodiments, the root development zones are
biodegradable.
[0145] In some embodiments, the root development zones, when
swelled in soil, have a pH or osmotic pressure that differs from
the pH or osmotic pressure of the surrounding soil by at least
about 10%.
[0146] In some embodiments, the root development zones do not
contain the at least one agrochemical before the unit is swelled
for the first time.
[0147] In some embodiments, the root development zones further
comprise the at least one agrochemical before the unit is swelled
for the first time.
[0148] In some embodiments, the amount of the at least one
agrochemical in the root development zones is about 5%, 10%, 15% or
20% (w/w) of the amount of the at least one agrochemical that is in
the agrochemical zones.
[0149] In some embodiments, the widest part of the unit is about 1,
2, 3, 4, 5, 6, 7, 8, 9, 10 cm, or more than 10 cm when the root
development zones are about 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%,
40%, 45%, 50%, 1-50% or 5-50% swelled.
[0150] In some embodiments, when the root development zones are
about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 5-50%
swelled, the total weight of the root development zones is at least
about 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90,
100 or more than 100 times greater than the total weight of the
agrochemical zones.
[0151] In some embodiments, the root development zones comprise a
synthetic hydrogel, a natural carbohydrate hydrogel, or a pectin or
protein hydrogel, or any combination thereof.
[0152] In some embodiments, the synthetic hydrogel comprises
acrylamide, an acrylic derivative, or any combination thereof.
[0153] In some embodiments, the natural carbohydrate hydrogel
comprises agar, cellulose, chitosan, starch, hyaluronic acid, a
dextrine, a natural gum, a sulfated polysaccharide, or any
combination thereof.
[0154] In some embodiments, the pectin or protein hydrogel
comprises gelatin, a gelatin derivative, collagen, a collagen
derivative, or any combination thereof.
[0155] In some embodiments, the root development zones comprise a
natural super absorbent polymer (SAP), a poly-sugar SAP, a
semi-synthetic SAP, a fully-synthetic SAP, or any combination
thereof.
[0156] In some embodiments, the root development zones comprise a
combination of at least one natural SAP and at least one
semi-synthetic or synthetic SAP.
[0157] In some embodiments, the root development zones comprise a
poly-sugar SAP.
[0158] In some embodiments, the poly-sugar SAP is alginate.
[0159] In some embodiments, the alginate is at least about 0.2%
alginate.
[0160] In some embodiments, the root development zones comprise a
semi-synthetic SAP.
[0161] In some embodiments, the semi-synthetic SAP is a
CMC-g-polyacrylic acid SAP.
[0162] In some embodiments, the Caboxymethyl cellulose (CMC)
grafted polyacrylic acid SAP comprises 6% CMC relative to the
acrylic monomers (Acrylamide-acrylic), 6% CMC relative to acrylic
acid, 25% CMC relative to acrylic acid, or CMC 50% AA.
[0163] In some embodiments, the CMC grafted SAP comprises 5-50% CMC
relative the acrylic monomers.
[0164] In some embodiments, the CMC grafted SAP comprises 6-12% CMC
relative the acrylic monomers.
[0165] In some embodiments, the semi-synthetic SAP is k-carrageenan
cross-linked-polyacrylic acid SAP.
[0166] In some embodiments, the SAP is other than alginate or a
k-carrageenan cross-linked-polyacrylic acid SAP.
[0167] In some embodiments, the root development zones comprise a
fully synthetic SAP.
[0168] In some embodiments, the fully synthetic SAP is acrylic acid
or acrylic amide or any of the combinations thereof.
[0169] In some embodiments, the amount of cross-linker in the root
development zones is below 5% relative to the total monomer content
by weight. In some embodiments, the amount of cross-linker in the
root development zones is below 2% relative to the total monomer
content by weight. In some embodiments, the amount of cross-linker
in the root development zones is below 1% relative to the total
monomer content by weight.
[0170] In some embodiments, the polymer content of a swelled unit
is below 5% by weight. In some embodiments, the polymer content of
a swelled unit is below 4%, below 3%, below 2%, or below 1% by
weight.
[0171] In some embodiments, the root development zones further
comprise at least one oxygen carrier that increases the amount of
oxygen in the root development zones compared to corresponding root
development zones not comprising the oxygen carrier.
[0172] In some embodiments, the at least one oxygen carrier is a
perfluorocarbon.
[0173] In some embodiments, the agrochemical zones comprise an
organic polymer, a natural polymer, or an inorganic polymer, or any
combination thereof.
[0174] In some embodiments, the agrochemical zones are partially or
fully coated with a coating system.
[0175] In some embodiments, the coating system dissolves into the
root development zones when the root development zones are
swelled.
[0176] In some embodiments, the coating system slows the rate at
which the at least one agrochemical dissolves into the root
development zones when the root development zones are swelled.
[0177] In some embodiments, the units comprise a coating system
which covers all surfaces of the agrochemical zones which would
otherwise be on the surface of the unit and which is impermeable to
the at least one agrochemical.
[0178] In some embodiments, the coating system is silicate or
silicon dioxide.
[0179] In some embodiments, the coating system is a polymer.
[0180] In some embodiments, the coating system is an
agrochemical.
[0181] In some embodiments, the agrochemical zones comprise a
polymer.
[0182] In some embodiments, the polymer is a highly cross-linked
polymer.
[0183] In some embodiments, the highly cross-linked polymer is a
poly-sugar or a poly-acrylic polymer.
[0184] In some embodiments, the agrochemical zones comprises a
filler.
[0185] In some embodiments, the filler comprises a cellulosic
material, a cellite, a polymeric material, a silicon dioxide, a
phyllosilicate, a clay mineral, metal oxide particles, porous
particles, or any combination thereof.
[0186] In some embodiments, the filler comprises a phyllosilicate
of the serpentine group.
[0187] In some embodiments, the a phyllosilicate of the serpentine
group is antigorite (Mg.sub.3Si.sub.2O.sub.5(OH).sub.4), chrysotile
(Mg.sub.3Si.sub.2O.sub.5(OH).sub.4), or lizardite
(Mg.sub.3Si.sub.2O.sub.5(OH).sub.4).
[0188] In some embodiments, the filler comprises a clay mineral,
which is halloysite (Al.sub.2Si.sub.2O.sub.5(OH).sub.4), kaolinite
(Al.sub.2Si.sub.2O.sub.5(OH).sub.4), illite
((K,H.sub.3O)(Al,Mg,Fe).sub.2(Si,Al).sub.4O.sub.10[(OH).sub.2,(H.sub.2O)]-
), montmorillonite
((Na,Ca).sub.0.33(Al,Mg).sub.2Si.sub.4O.sub.10(OH).sub.2.nH.sub.2O),
vermiculite
((MgFe,Al).sub.3(Al,Si).sub.4O.sub.10(OH).sub.2.4H.sub.2O), talc
(Mg.sub.3Si.sub.4O.sub.10(OH).sub.2), palygorskite
((Mg,Al).sub.2Si.sub.4O.sub.10(OH).4(H.sub.2O), or pyrophyllite
(Al.sub.2Si.sub.4O.sub.10(OH).sub.2).
[0189] In some embodiments, the filler comprises a phyllosilicate
of the mica group.
[0190] In some embodiments, the phyllosilicate of the mica group is
biotite (K(Mg,Fe).sub.3(AlSi.sub.3)O.sub.10(OH).sub.2), muscovite
(KAl.sub.2(AlSi.sub.3)O.sub.10(OH).sub.2), phlogopite
(KMg.sub.3(AlSi.sub.3)O.sub.10(OH).sub.2), lepidolite
(K(Li,Al).sub.2-3(AlSi.sub.3)O.sub.10(OH).sub.2), margarite
(CaAl.sub.2(Al.sub.2Si.sub.2)O.sub.10(OH).sub.2), glauconite
((K,Na)(Al,Mg,Fe).sub.2(Si,Al).sub.4O.sub.10(OH).sub.2), or any
combination thereof.
[0191] In some embodiments, the filler comprises a phyllosilicate
of the chlorite group.
[0192] In some embodiments, the a phyllosilicate of the chlorite
group is chlorite
((Mg,Fe).sub.3(Si,Al).sub.4O.sub.10(OH).sub.2.(Mg,Fe).sub.3(OH).-
sub.6).
[0193] In some embodiments, the filler forms a beehive-like
structure.
[0194] In some embodiments, the beehive-like structure is
microscopic.
[0195] In some embodiments, the filler comprises clay.
[0196] In some embodiments, the filler comprises zeolite.
[0197] In some embodiments, the agrochemical zones comprise at
least about 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1
grams of the at least one agrochemical.
[0198] In some embodiments, the agrochemical zones comprise 1-10
grams of the at least one agrochemical.
[0199] In some embodiments, the agrochemical zones are about 30%,
35%, 40%, 45%, 50%, 55%, or 60% of the at least one agrochemical by
weight.
[0200] In some embodiments, the agrochemical zones are
biodegradable.
[0201] In some embodiments, the unit comprises one agrochemical
zone.
[0202] In some embodiments, the unit comprises 2, 3, 4, 5, 6, 7, 8,
9, 10 or more than 10 agrochemical zones.
[0203] In some embodiments, the unit comprises 2, 3, 4, 5, 6, 7, 8,
9, 10 or more than 10 root development zones.
[0204] In some embodiments, the at least one agrochemical is:
[0205] i) at least one fertilizer compound; [0206] ii) at least one
pesticide compound, [0207] iii) at least one hormone compound;
[0208] iv) at least one drug compound; [0209] v) at least one
chemical growth agents; [0210] vi) at least one enzyme; [0211] vii)
at least one growth promoter; and/or [0212] viii) at least one
microelement.
[0213] In some embodiments, the at least one fertilizer compound is
a natural fertilizer.
[0214] In some embodiments, the at least one fertilizer compound is
a synthetic fertilizer.
[0215] In some embodiments, the at least one pesticide compound is:
[0216] i) at least one insecticide compound; [0217] ii) at least
one nematicide compound; [0218] iii) at least one herbicide
compound; and/or
[0219] iv) at least one fungicide compound.
[0220] In some embodiments, the at least one insecticide compound
is imidacloprid.
[0221] In some embodiments, the at least one herbicide compound is
pendimethalin.
[0222] In some embodiments, the at least one fungicide compound is
azoxystrobin.
[0223] In some embodiments, the at least one nematicide compound is
fluensulfone.
[0224] In some embodiments, the at least one fertilizer compound is
PO.sub.4, NO.sub.3, (NH.sub.4).sub.2SO.sub.2,
NH.sub.4H.sub.2PO.sub.4, and/or KCl.
[0225] In some embodiments, the at least one fertilizer compound
comprises multiple fertilizer compounds which include PO.sub.4,
NO.sub.3, (NH.sub.4).sub.2SO.sub.2, NH.sub.4H.sub.2PO.sub.4, and/or
KCl.
[0226] In some embodiments, the at least one agrochemical is at
least one fertilizer compound and at least one pesticide
compound.
[0227] In some embodiments, the at least one agrochemical is at
least one pesticide compound.
[0228] In some embodiments, the at least one agrochemical is at
least one fertilizer compound.
[0229] In some embodiments, the at least one pesticide compound is
at least one pesticide compound that is not suitable for
application to an agricultural field.
[0230] In some embodiments, the at least one pesticide compound
that is not suitable for application to an agricultural field is
too toxic to be applied to an agricultural field.
[0231] In some embodiments, the at least one pesticide compound is
toxic to animals other than arthropods or mollusks when applied to
an agricultural field in an amount that is sufficient to kill an
arthropod or a mollusk.
[0232] In some embodiments, the at least one agrochemical is
released from the agrochemical zones over a period of at least
about one week when the root development zones are swelled.
[0233] In some embodiments, the at least one agrochemical is
released from the agrochemical zones into the root development
zones over a period of at least about 2, 3, 4, 5, 6, 7, 8, 9, 10,
or 20 weeks when the root development zones are swelled.
[0234] In some embodiments, the at least one agrochemical is
released from the agrochemical zones into the root development
zones over a period of at least about 2, 3, 4, 5, 6, 7, 8, 9, 10,
or 20 weeks when the root development zones are about 1%, 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50% or 5-50% swelled.
[0235] In some embodiments, when the root development zones are
swelled and the unit is in soil, the at least one agrochemical
diffuses from the surface of the unit into the surrounding soil at
a linear rate beginning about 25 days after hydration.
[0236] In some embodiments, when the root development zones of the
unit are swelled and the unit is in soil, the at least one
agrochemical diffuses from the surface of the unit into the
surrounding soil for at least about 50 or 75 days after
hydration.
[0237] In some embodiments, the unit is not swelled.
[0238] In some embodiments, the unit contains less than about 35%,
30%, 25%, 20%, 15%, or 10% water by weight.
[0239] In some embodiments, the unit comprises one or more
interface zone between the agrochemical zones and the root
development zones, which interface zone is formed by at least one
insoluble salt or solid, at least one cross-linking agent, or at
least one inorganic compound.
[0240] In some embodiments, diffusion between the root development
zones and the agrochemical zones is limited by altering the pH or
the cation concentration in the agrochemical zones, the root
development zones, or the interface zone.
[0241] In some embodiments, diffusion between the root development
zones and the agrochemical zones is limited by altering the pH
and/or cation concentration in the agrochemical zone or the root
development zone.
[0242] In some embodiments, the pH in the agrochemical zones or the
root development zones is altered by a buffer.
[0243] In some embodiments, the pH in the agrochemical zones, the
interface zones, and the root development zones is altered by a
buffer.
[0244] The invention provides a method of growing a plant,
comprising adding at least one unit of the invention to the medium
in which the plant is grown.
[0245] In some embodiments, the method comprises a step of
selecting the size of the unit based upon the specific plant to be
grown. For example, it may be desirable to select a unit having a
large swelled size when growing a plant having large diameter roots
and it may be desirable to select a unit having a smaller swelled
size when growing a plant having small diameter roots. In some
embodiments, it may be desirable to use more units of a given size
when growing a plant having a large root system than when growing a
plant having a small root system.
[0246] In some embodiments, the medium in which the plant is grown
comprises soil.
[0247] In some embodiments, the medium in which the plant is grown
is soil.
[0248] In some embodiments, the soil comprises sand, silt, clay, or
any combination thereof.
[0249] In some embodiments, the soil is clay, loam, clay-loam, or
silt-loam.
[0250] In some embodiments, the soil is an Andisol.
[0251] In some embodiments, the at least one unit is added to the
soil at one or more depths below the soil surface. In some
embodiments, the at least one unit is added at a depth of 5-50 cm.
In some embodiments, the at least one unit is added at a depth of 5
cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, or 50
cm, or any combination of 2, 3, or 4 of the foregoing depths.
[0252] The invention provides a method of reducing environmental
damage caused by an agrochemical, comprising delivering the
agrochemical to the root of a plant by adding at least one unit of
the invention to the medium of the plant.
[0253] The present invention provides a method of minimizing
exposure to an agrochemical, comprising delivering the agrochemical
to the root of a plant by adding at least one unit of the invention
to the medium of the plant.
[0254] In some embodiments, minimizing exposure to the agrochemical
is minimizing the exposure of a farmer to the agrochemical.
[0255] In some embodiments, minimizing exposure to the agrochemical
is minimizing exposure of a person other than the farmer to the
agrochemical.
[0256] The present invention provides a method of generating an
artificial zone with predetermined chemical properties within the
root zone of a plant, comprising: [0257] i) adding one or more
units of the invention to the root zone of the plant; or [0258] ii)
adding one or more units of the invention to the anticipated root
zone of the medium in which the plant is anticipated to grow.
[0259] In some embodiments, step i) comprises adding at least two
different units to the root zone of the plant; and step ii)
comprises adding at least two different units to the anticipated
root zone of the medium in which the plant is anticipated to grow,
wherein at least one of the at least two different units is a unit
of the invention.
[0260] In some embodiments, each of the at least two different
units contains at least one agrochemical that is not contained
within one of the other at least two different units.
[0261] In some embodiments, the plant is grown in a field.
[0262] In some embodiments, the plant is a crop plant.
[0263] In some embodiments, the crop plant is a grain or a tree
crop plant.
[0264] In some embodiments, the crop plant is a fruit or a
vegetable plant.
[0265] In some embodiments, the plant is a banana, barley, bean,
cassava, corn, cotton, grape, orange, pea, potato, rice, soybean,
sugar beet, tomato, or wheat plant.
[0266] In some embodiments, the plant is a sunflower, cabbage
plant, lettuce, or celery plant.
[0267] The present invention provides a method of increasing the
yield of a plant, comprising (i) adding one or more units of the
invention to a medium where the plant is growing or is to be grown,
and (ii) growing the plant, wherein the yield of the plant is
higher when grown in the medium containing the units than in the
medium not containing the units.
[0268] The present invention provides a method of increasing the
growth rate of a plant, comprising (i) adding one or more units of
the invention to a medium where the plant is growing or is to be
grown, and (ii) growing the plant, wherein the plant grows faster
in the medium containing the units than in the medium not
containing the units.
[0269] The present invention provides a method of increasing the
size of a plant, comprising (i) adding one or more units of the
invention to a medium where the plant is growing or is to be grown,
and (ii) growing the plant, wherein the plant grows larger in the
medium containing the units than in the medium not containing the
units.
[0270] The present invention provides a method of increasing N, P,
and/or K uptake by a plant, comprising (i) adding one or more units
of the invention to a medium where the plant is growing or is to be
grown, and (ii) growing the plant, wherein the N, P, and/or K
uptake of the plant is greater in the medium containing the units
than in the medium not containing the units.
[0271] The present invention provides a method of protecting a
plant from low ambient temperatures, comprising (i) adding one or
more units of the invention to a medium where the plant is growing
or is to be grown, and (ii) growing the plant, wherein plants grown
in the medium containing the units have greater survival rates
under low ambient temperatures than plants grown in the medium not
containing the units.
[0272] In some embodiments, low ambient temperature is below
15.degree. C., below 12.degree. C., below 10.degree. C., below
8.degree. C., below 6.degree. C., below 4.degree. C., below
2.degree. C., or below 0.degree. C.
[0273] In some embodiments, the units are added to the medium where
the plant is growing.
[0274] In some embodiments, the units are added to the medium where
the plant is to be grown.
[0275] In some embodiments, seeds for growing the plant are added
to the medium before the units are added to the medium.
[0276] In some embodiments, seeds for growing the plant are added
to the medium at the same time the units are added to the
medium.
[0277] In some embodiments, seeds for growing the plant are added
to the medium after the units are added to the medium.
[0278] In some embodiments, the medium is soil.
[0279] In some embodiments, the units comprise one fertilizer
compound. In some embodiments, the units comprise two fertilizer
compounds. In some embodiments, the units comprise three fertilizer
compounds. In some embodiments, the units comprise more than three
fertilizer compounds.
[0280] In some embodiments, the units comprise one to three
fertilizer compounds, such that the total N, P, and/or K content as
(NH.sub.4).sub.2SO.sub.2, NH.sub.4H.sub.2PO.sub.4, and KCl in the
medium as part of the units is about 5-50, 1-10, and 5-60
g/m.sup.2, respectively.
[0281] In some embodiments, the units comprise three fertilizer
compounds, such that the total N, P, and K content as
(NH.sub.4).sub.2SO.sub.2, NH.sub.4H.sub.2PO.sub.4, and KCl in the
medium as part of the units is about 25, 5, and 30 g/m.sup.2,
respectively.
[0282] The invention also provides a method of making a unit of the
invention comprising encapsulating at least one agrochemical zone
within a SAP.
[0283] In some embodiments, encapsulating comprises polymerizing
the SAP around the at least one agrochemical zone.
[0284] In some embodiments, encapsulating comprises a first
polymerization step and a second polymerization step.
[0285] In some embodiments, the first polymerization step comprises
forming a three dimensional structure of SAP having a cavity into
which the at least one agrochemical zone can be placed, and the
second polymerization step comprises sealing the cavity with
additional SAP.
[0286] In some embodiments, the at least one agrochemical zone is
placed in the cavity prior to the second polymerization step.
[0287] The present invention provides a bead comprising: [0288] i)
an external zone comprising a super absorbent polymer (SAP) that is
capable of absorbing at least about 5 times its weight in water,
[0289] surrounding [0290] ii) at least one internal zone comprising
a core that contains at least one agrochemical, wherein the
external zone is permeable to oxygen when hydrated, or the internal
zone is formulated to release the at least one agrochemical into
the external zone over a period of at least about one week when the
hydrogel of the external zone is hydrated.
[0291] The present invention provides a bead comprising: [0292] i)
an external zone comprising a super absorbent polymer (SAP) that is
capable of absorbing at least about 5 times its weight in water,
[0293] surrounding [0294] ii) at least one internal zone comprising
a core that contains at least one agrochemical, wherein the
external zone is permeable to oxygen when hydrated, and the
internal zone is formulated to release the at least one
agrochemical into the external zone over a period of at least about
one week when the hydrogel of the external zone is hydrated.
[0295] In some embodiments, the SAP is capable of absorbing at
least about 50, 75, 80, 85, 90, 95, 100, 200, 300, 400, 500, or
1000 times its weight in water.
[0296] In some embodiments, the SAP is permeable to oxygen.
[0297] In some embodiments, the SAP is permeable to oxygen such
that it maintains at least about 6 mg/L of dissolved oxygen in the
SAP when it is hydrated.
[0298] In some embodiments, the SAP when fully hydrated is at least
about 70, 75, 80, 85, 90, 95, or 100% as permeable to oxygen as
hydrated alginate or hydrated semi-synthetic CMC.
[0299] In some embodiments, the SAP is an aerogel, a hydrogel or an
organogel.
[0300] In some embodiments, the SAP is a hydrogel.
[0301] In some embodiments, the external zone further comprises a
polymer, a porous inorganic material, a porous organic material, or
any combination thereof.
[0302] In some embodiments, the internal zone further comprises an
aerogel, a hydrogel, an organogel, a polymer, a porous inorganic
material, a porous organic material, or any combination
thereof.
[0303] In some embodiments, roots of a crop plant are capable of
penetrating the hydrogel when the hydrogel is about 1%, 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50% or 5-50%
hydrated.
[0304] In some embodiments, roots of a crop plant are capable of
penetrating the hydrogel when the hydrogel is about 1%, 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50% or 5-50%
hydrated.
[0305] In some embodiments, roots of a crop plant are capable of
growing within the hydrogel when the hydrogel is hydrated.
[0306] In some embodiments, roots of a crop plant are capable of
growing within the hydrogel when the hydrogel is about 1%, 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50% or 5-50%
hydrated.
[0307] In some embodiments, roots of a crop plant are capable of
growing within the hydrogel when the hydrogel is hydrated.
[0308] In some embodiments, roots of a crop plant are capable of
growing within the hydrogel when the hydrogel is about 1%, 5%, 10%,
15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 1-50% or 5-50%
hydrated.
[0309] In some embodiments, the crop plant is a sunflower plant. In
some embodiments, the crop plant is a cabbage plant. In some
embodiments, the crop plant is wheat plant. In some embodiments,
the crop plant is maize plant. In some embodiments, the crop plant
is a soybean plant. In some embodiments, the crop plant is a rice
plant. In some embodiments, the crop plant is a barley plant. In
some embodiments, the crop plant is a cotton plant. In some
embodiments, the crop plant is a pea plant. In some embodiments,
the crop plant is a potato plant. In some embodiments, the crop
plant is a tree crop plant. In some embodiments, the crop plant is
a vegetable plant.
[0310] In some embodiments, the hydrogel is capable of repeated
swelling cycles that each comprises hydration followed by
dehydration.
[0311] In some embodiments, the hydrogel is capable of repeated
swelling cycles in soil that each comprise hydration followed by
dehydration while in the soil.
[0312] In some embodiments, the bead is in the shape of a sphere or
an equivalent polyhedron. In some embodiments, the polyhedron is
six sided. In some embodiments, the polyhedron is a cube.
[0313] In some embodiments, the bead is in the shape of a sphere or
an equivalent polyhedron after repeated swelling cycles.
[0314] In some embodiments, the bead is in the shape of a cylinder.
In some embodiments, the bead is in the shape of a cylinder after
repeated swelling cycles.
[0315] In some embodiments, the bead is in the shape of a disc.
[0316] In some embodiments, the hydrogel, when hydrated, maintains
at least about 75%, 80%, 85%, 90%, or 95% of its water content over
a period of at least about 25, 50, 100, or 150 hours in soil.
[0317] In some embodiments, the hydrogel, when hydrated, maintains
at least about 75%, 80%, 85%, 90%, or 95% of its water content over
a period of at least about 25, 50, 100, or 150 hours in sandy
soil.
[0318] In some embodiments, the hydrogel, when hydrated, maintains
at least about 75%, 80%, 85%, 90%, or 95% of its volume over a
period of at least about 25, 50, 100, or 150 hours in soil.
[0319] In some embodiments, the hydrogel, when hydrated, maintains
at least about 75%, 80%, 85%, 90%, or 95% of its volume over a
period of at least about 25, 50, 100, or 150 hours in sandy
soil.
[0320] In some embodiments, the hydrogel, when hydrated, maintains
its shape over a period of at least about 25, 50, 100, or 150 hours
in soil.
[0321] In some embodiments, the hydrogel, when hydrated, maintains
spherical shape over a period of at least about 25, 50, 100, or 150
hours in sandy soil.
[0322] In some embodiments, the hydrogel, when hydrated, maintains
its shape after repeated swelling cycles that each comprises
hydration followed by dehydration.
[0323] In some embodiments the hydrogel, when hydrated maintains
its shape after at least 3 swelling cycles that each comprises
hydration followed by dehydration.
[0324] In some embodiments, the SAP is biodegradable.
[0325] In some embodiments, when hydrated in soil, the external
zone of the bead has a pH or osmotic pressure that differs from the
pH or osmotic pressure of the surrounding soil by at least about
10%.
[0326] In some embodiments, the external zone does not contain the
at least one agrochemical before the bead is hydrated for the first
time.
[0327] In some embodiments, the external zone also contains the at
least one agrochemical.
[0328] In some embodiments, the amount of the at least one
agrochemical in the external zone is about 5%, 10%, 15% or 20%
(w/w) of the amount of the at least one agrochemical that is in the
internal zone.
[0329] In some embodiments, the bead has a maximum diameter of
about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 cm when the SAP of the
external zone is about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%,
50%, or 5-50% hydrated.
[0330] In some embodiments, when the SAP of the external zone is
about 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 5-50%
hydrated, the weight of the external zone is at least about 2, 3,
4, 5, 6, 7, 8, 9, or 10 times greater than the weight of the
internal zone.
[0331] In some embodiments, the hydrogel is a synthetic hydrogel, a
natural carbohydrate hydrogel, or a pectin or protein hydrogel, or
any combination thereof.
[0332] In some embodiments, the synthetic hydrogel comprises
acrylamide, an acrylic derivative, or any combination thereof.
[0333] In some embodiments, the natural carbohydrate hydrogel
comprises agar, cellulose, chitosan, starch, hyaluronic acid, a
dextrine, a natural gum, a sulfated polysaccharide, or any
combination thereof.
[0334] In some embodiments, the pectin or protein hydrogel
comprises gelatin, a gelatin derivative, collagen, a collagen
derivative, or any combination thereof.
[0335] In some embodiments, the hydrogel comprises a natural super
absorbent polymer (SAP), a poly-sugar SAP, a semi-synthetic SAP, a
fully-synthetic SAP, or any combination thereof.
[0336] In some embodiments, the hydrogel comprises a combination of
at least one natural SAP and at least one semi-synthetic or
synthetic SAP.
[0337] In some embodiments, the hydrogel comprises a poly-sugar
SAP.
[0338] In some embodiments, the poly-sugar SAP is alginate.
[0339] In some embodiments, the alginate is at least about 0.2%
alginate.
[0340] In some embodiments, the hydrogel comprises a semi-synthetic
SAP.
[0341] In some embodiments, the semi-synthetic SAP is a
CMC-g-polyacrylic acid SAP.
[0342] In some embodiments, the Caboxymethyl cellulose (CMC)
grafted polyacrylic acid SAP comprises 6% CMC relative to the
acrylic monomers (Acrylamide-acrylic), 6% CMC relative to acrylic
acid, 25% CMC relative to acrylic acid, or CMC 50% AA.
[0343] In some embodiments, the SAP is other than alginate or a
k-carrageenan cross-linked-polyacrylic acid SAP.
[0344] In some embodiments, the SAP is a k-carrageenan
cross-linked-polyacrylic acid SAP.
[0345] In some embodiments, the hydrogel comprises a fully
synthetic SAP.
[0346] In some embodiments, the fully synthetic SAP is acrylic acid
or acrylic amide or any of the combinations thereof.
[0347] In some embodiments, the external zone further comprises at
least one oxygen carrier that increases the amount of oxygen in the
external zone compared to a corresponding external zone not
comprising the oxygen carrier.
[0348] In some embodiments, the at least one oxygen carrier is a
perfluorocarbon.
[0349] In some embodiments the internal zone comprises an organic
polymer, a natural polymer, or an inorganic polymer, or any
combination thereof.
[0350] In some embodiments, the at least one core is coated with at
least one coat compound.
[0351] In some embodiments, the at least one coat compound
dissolves into the SAP when the SAP is hydrated.
[0352] In some embodiments, the at least one coat compound slows
the rate at which the at least one agrochemical dissolves into the
SAP when the SAP is hydrated.
[0353] In some embodiments, the at least one coat compound is
silicate or silicon dioxide.
[0354] In some embodiments, the at least one coat compound is the
at least one agrochemical.
[0355] In some embodiments, the at least one core comprises a
polymer.
[0356] In some embodiments, the polymer is a highly cross-linked
polymer.
[0357] In some embodiments, the highly cross-linked polymer is a
poly-sugar or a poly-acrylic polymer.
[0358] In some embodiments, the at least one core comprises a
filler.
[0359] In some embodiments, the filler comprises a cellulosic
material, a cellite, a polymeric material, a silicon dioxide, a
phyllosilicate, a clay mineral, metal oxide particles, porous
particles, or any combination thereof.
[0360] In some embodiments, the filler comprises a phyllosilicate
of the serpentine group.
[0361] In some embodiments, the a phyllosilicate of the serpentine
group is antigorite (Mg.sub.3Si.sub.2O.sub.5(OH).sub.4), chrysotile
(Mg.sub.3Si.sub.2O.sub.5(OH).sub.4), or lizardite
(Mg.sub.3Si.sub.2O.sub.5(OH).sub.4).
[0362] In some embodiments, the filler comprises a clay mineral,
which is halloysite (Al.sub.2Si.sub.2O.sub.5(OH).sub.4), kaolinite
(Al.sub.2Si.sub.2O.sub.5(OH).sub.4), illite
((K,H.sub.3O)(Al,Mg,Fe).sub.2(Si,Al).sub.4O.sub.10[(OH).sub.2,(H.sub.2O)]-
), montmorillonite
((Na,Ca).sub.0.33(Al,Mg).sub.2Si.sub.4O.sub.10(OH).sub.2.nH.sub.2O),
vermiculite
((MgFe,Al).sub.3(Al,Si).sub.4O.sub.10(OH).sub.2.4H.sub.2O), talc
(Mg.sub.3Si.sub.4O.sub.10(OH).sub.2), palygorskite
((Mg,Al).sub.2Si.sub.4O.sub.10(OH).4(H.sub.2O), or pyrophyllite
(Al.sub.2Si.sub.4O.sub.10(OH).sub.2).
[0363] In some embodiments, the filler comprises a phyllosilicate
of the mica group.
[0364] In some embodiments, the a phyllosilicate of the mica group
is biotite (K(Mg,Fe).sub.3(AlSi.sub.3)O.sub.10(OH).sub.2),
muscovite (KAl.sub.2(AlSi.sub.3)O.sub.10(OH).sub.2), phlogopite
(KMg.sub.3(AlSi.sub.3)O.sub.10(OH).sub.2), lepidolite
(K(Li,Al).sub.2-3(AlSi.sub.3)O.sub.10(OH).sub.2), margarite
(CaAl.sub.2(Al.sub.2Si.sub.2)O.sub.10(OH).sub.2), glauconite
((K,Na)(Al,Mg,Fe).sub.2(Si,Al).sub.4O.sub.10(OH).sub.2), or any
combination thereof.
[0365] In some embodiments, the filler comprises a phyllosilicate
of the chlorite group.
[0366] In some embodiments, the a phyllosilicate of the chlorite
group is chlorite
((Mg,Fe).sub.3(Si,Al).sub.4O.sub.10(OH).sub.2.(Mg,Fe).sub.3(OH).-
sub.6).
[0367] In some embodiments, the filler forms a beehive-like
structure.
[0368] In some embodiments, the beehive-like structure is
microscopic.
[0369] In some embodiments, the filler comprises clay.
[0370] In some embodiments, the filler comprises zeolite.
[0371] In some embodiments, the core comprises at least about 0.05,
0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1 grams of the at
least one agrochemical. In some embodiments, the core comprises
1-10 grams of the at least one agrochemical.
[0372] In some embodiments, the core is about 30%, 35%, 40%, 45%,
50%, 55%, or 60% of the at least one agrochemical by weight.
[0373] In some embodiments, weight of the bead is 1-10 g. In some
embodiments, the weight of the bead is 6-7 g. In some embodiments,
the weight of the bead is 3.5-4 g.
[0374] In some embodiments, the at least one core is
biodegradable.
[0375] In some embodiments, the internal zone contains one
core.
[0376] In some embodiments, the internal zone contains more than
one core.
[0377] In some embodiments, the at least one agrochemical is:
[0378] i) at least one fertilizer compound; [0379] ii) at least one
pesticide compound, [0380] iii) at least one hormone compound;
[0381] iv) at least one ding compound; [0382] v) at least one
chemical growth agents; and/or [0383] vi) at least one
microelement.
[0384] In some embodiments, the at least one fertilizer compound is
a natural fertilizer.
[0385] In some embodiments, the at least one fertilizer compound is
a synthetic fertilizer.
[0386] In some embodiments, the at least one pesticide compound is:
[0387] i) at least one insecticide compound; [0388] ii) at least
one nematicide compound; [0389] iii) at least one herbicide
compound; and/or [0390] iv) at least one fungicide compound.
[0391] In some embodiments, the at least one insecticide compound
is imidacloprid.
[0392] In some embodiments, the at least one herbicide compound is
pendimethalin.
[0393] In some embodiments, the at least one fungicide compound is
azoxystrobin.
[0394] In some embodiments, the at least one nematicide compound is
fluensulfone.
[0395] In some embodiments, the at least one fertilizer compound is
PO.sub.4, NO.sub.3, (NH.sub.4).sub.2SO.sub.2,
NH.sub.4H.sub.2PO.sub.4, and/or KCl.
[0396] In some embodiments, the at least one fertilizer compound
comprises multiple fertilizer compounds which include PO.sub.4,
NO.sub.3, (NH.sub.4).sub.2SO.sub.2, NH.sub.4H.sub.2PO.sub.4, and/or
KCl.
[0397] In some embodiments, the at least one agrochemical is at
least one fertilizer compound and at least one pesticide
compound.
[0398] In some embodiments, the at least one agrochemical is at
least one pesticide compound.
[0399] In some embodiments, the at least one agrochemical is at
least one fertilizer compound.
[0400] In some embodiments, the at least one pesticide compound is
at least one pesticide compound that is not suitable for
application to an agricultural field.
[0401] In some embodiments, the at least one pesticide compound
that is not suitable for application to an agricultural field is
too toxic to be applied to an agricultural field.
[0402] In some embodiments, the at least one pesticide compound is
toxic to animals other than arthropods or mollusks when applied to
an agricultural field in an amount that is sufficient to kill an
arthropod or a mollusk.
[0403] In some embodiments, the at least one agrochemical is
released from the core of the internal zone over a period of at
least about one week when the SAP of the external zone is
hydrated.
[0404] In some embodiments, the at least one agrochemical is
released from the core of the internal zone over a period of at
least about one week when the SAP of the external zone is
hydrated.
[0405] In some embodiments, the at least one agrochemical is
released from the internal zone into the external zone over a
period of at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, or 20 weeks
when the SAP of the external zone is hydrated.
[0406] In some embodiments, the at least one agrochemical is
released from the internal zone into the external zone over a
period of at least about 2, 3, 4, 5, 6, 7, 8, 9, 10, or 20 weeks
when the SAP of the external zone is about 5%, 10%, 15%, 20%, 25%,
30%, 35%, 40%, 45%, 50%, or 5-50% hydrated.
[0407] In some embodiments, when the SAP of the bead is hydrated
and the bead is in soil, the at least one agrochemical diffuses
from the surface of the bead into the surrounding soil at a linear
rate beginning about 25 days after hydration.
[0408] In some embodiments, when the SAP of the bead is hydrated
and the bead is in soil, the at least one agrochemical diffuses
from the surface of the bead into the surrounding soil for at least
about 50 or 75 days after hydration.
[0409] In some embodiments, the bead is not hydrated.
[0410] In some embodiments, the bead contains less than about 35%,
30%, 25%, 20%, 15%, or 10% water by weight.
[0411] In some embodiments, the bead further comprises an interface
zone between the internal zone and the external zone, which
interface zone is formed by at least one insoluble salt or solid,
at least one cross-linking agent, or at least one inorganic
compound.
[0412] In some embodiments, diffusion between the external zone and
the internal zone is limited by altering the pH or the cation
concentration in the internal zone, the external zone, or the
interface zone.
[0413] In some embodiments, diffusion between the external zone and
the internal zone is limited by altering the pH and/or cation
concentration in the internal zone or the external zone.
[0414] In some embodiments, the pH in the internal zone or the
external zone is altered by a buffer.
[0415] In some embodiments, the pH in the internal zone, the
external zone, or the interface zone is altered by a buffer.
[0416] The present invention provides a method of growing a plant,
comprising adding at least one bead of the invention to the medium
in which the plant is grown.
[0417] In some embodiments, the medium in which the plant is grown
comprises soil.
[0418] In some embodiments, the medium in which the plant is grown
is soil.
[0419] In some embodiments, the soil comprises sand, silt, clay, or
any combination thereof.
[0420] In some embodiments, the soil is clay, loam, clay-loam, or
silt-loam.
[0421] The present invention provides a method of growing a plant,
comprising adding multiple beads of the invention to the medium of
the plant, wherein the multiple beads comprise three fertilizer
compounds, such that the total N, P, and K content as
(NH.sub.4).sub.2SO.sub.2, NH.sub.4H.sub.2PO.sub.4, and KCl in the
medium as part of the beads is about 25, 5, and 30 g/m.sup.2,
respectively.
[0422] The present invention provides a method of generating an
artificial zone with predetermined chemical properties within the
root zone of a plant, comprising: [0423] i) adding at least two
different beads to the root zone of the plant; or [0424] ii) adding
at least two different beads to the anticipated root zone of the
medium in which the plant is anticipated to grow, wherein at least
one of the at least two different beads is a bead of an embodiment
of the invention.
[0425] In some embodiments, each of the at least two different
beads contains at least one agrochemical that is not contained
within one of the other at least two different of beads.
[0426] In some embodiments, the plant is grown in a field.
[0427] In some embodiments, the plant is a crop plant. In some
embodiments, the crop plant is a grain or a tree crop plant. In
some embodiments, the crop plant is a fruit or a vegetable
plant.
[0428] In some embodiments, the plant is a banana, barley, bean,
cassava, corn, cotton, grape, orange, pea, potato, rice, soybean,
sugar beet, tomato, or wheat plant.
[0429] The present invention provides an artificial environment for
plant growth comprising two parts, wherein part A forms a
continuous system with part B, whereas; [0430] Part A is a
controlled release reservoir of additive with a weight of at least
0.05 gr, and wherein; [0431] Part B is an artificial environment
comprised of at least 90% water when fully swelled, and its weight
is at least 5 times larger than part A.
[0432] The present invention provides an artificial environment for
plant growth comprising two parts, wherein part A is located inside
part B, whereas; [0433] Part A is a controlled release reservoir of
additive with a weight of at least 0.05 gr, and wherein; [0434]
Part B is a artificial environment comprised of at least 90% water
when fully swelled, and its weight is at least 5 times larger than
part A.
[0435] In some embodiments, the artificial environment is
synthesized so that one of the moisture, pH or osmotic pressure
inside the artificial environment is different by at least 10% from
the surrounding soil; and plant roots can penetrate and grow inside
the artificial environment volume.
[0436] In some embodiments, parts A and B are fabricated from
materials consisting of polymers, aerogels, hydrogels, organogels,
porous inorganic, porous organic material or a combination
thereof.
[0437] In some embodiments, part A is selected from the group
consisting of organic polymer, natural polymer, inorganic polymer
or a combination thereof.
[0438] In some embodiments, part A also comprises components in the
solids form.
[0439] In some embodiments, part A contains fillers selected from
the group consisting from clays, metal oxide particles, porous
particles or a combination thereof.
[0440] In some embodiments, additive is selected from the group
consisting of nutrients, agrochemicals, pesticides, microelements,
drugs or a combination thereof.
[0441] In some embodiments, part A comprises both structural
materials and functional materials.
[0442] In some embodiments, part B contains no fraction of said
additive, or at least 10 times lower concentration of said
additives then in Part A, when added to the soil.
[0443] In some embodiments, part B is selected from the group
consisting of organic polymer, natural polymer, inorganic polymer
or a combination thereof.
[0444] In some embodiments, part B contains fillers selected from
the group consisting from air, porous particles or a combination
thereof.
[0445] In some embodiments, the artificial environment is
transported to the field in a dry form, containing less than 30%
water.
[0446] In some embodiments, the dimension of the artificial
environment is at least 30 mL in the fully swelled form.
[0447] In some embodiments, the additive concentration in Part A is
at least 50%.
[0448] In some embodiments, after contacting Part A and Part B, an
interface is formed between the two parts by means of: the
formation of insoluble salts or solids, cross linking agents,
inorganic component chemistry or by altering pH or cation
concentration so as to limit the diffusion between the two parts
and the combination thereof.
[0449] In some embodiments, part A also comprises components in the
solids form.
[0450] In some embodiments, part A comprises both structural
materials and functional materials.
[0451] In some embodiments, the distance between the artificial
environment and the plant seed is between 0.1 to 500
centimeters.
[0452] In some embodiments, the distance between the artificial
environment and the plant seed is between 0.1 to 500 centimeters.
In some embodiments, the distance between the artificial
environment and the plant seed is about 0.5, 1, 15, 2, 2.5, 3, 3.5,
4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 15, 20, 25, 30,
35, 40, 45, 50, or 100 centimeters.
[0453] Non-limiting examples of structural materials of the present
invention are materials that give the structure of the system for
example water, aerogels, treated starch, treated cellulose,
polymers, superadsorbents and the functional materials are the
materials consumed by the plant for example, a fertilizer
compound.
[0454] Each embodiment disclosed herein is contemplated as being
applicable to each of the other disclosed embodiments. Thus, all
combinations of the various elements described herein are within
the scope of the invention.
[0455] It is understood that where a parameter range is provided,
all integers within that range, and tenths thereof, are also
provided by the invention. For example, "0.2-5 mg/kg/day" is a
disclosure of 0.2 mg/kg/day, 0.3 mg/kg/day, 0.4 mg/kg/day, 0.5
mg/kg/day, 0.6 mg/kg/day etc. up to 5.0 mg/kg/day.
Terms
[0456] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by a
person of ordinary skill in the art to which this invention
belongs.
[0457] As used herein, and unless stated otherwise or required
otherwise by context, each of the following terms shall have the
definition set forth below.
[0458] As used herein, "about" in the context of a numerical value
or range means .+-.10% of the numerical value or range recited or
claimed, unless the context requires a more limited range.
[0459] An "agrochemical zone" is a component of a unit of the
invention which contains at least one agrochemical and which
releases the at least one agrochemical into the root development
zones of a unit of the invention. In some embodiments, the at least
one agrochemical is released into the root development zones of a
unit of the invention by diffusion when the root development zones
of the unit are hydrated.
[0460] The term "coating system" means one or more compounds which
delays or prevents the release of an agrochemical from the surface
of an agrochemical zone which is covered by the coating system. In
some embodiments, the coating system comprises a single coat
compound. In some embodiments, the coating system comprises more
than one coat compound. In some embodiments, the coating system
comprises more than one layer. In some embodiments, each layer of
the coating system is of the same composition. In some embodiments,
each layer of the coating composition is of a different
composition. In some embodiments, the coating system comprises two,
three, or four layers.
[0461] The term "controlled release" when used to refer to an
agrochemical zone means that the agrochemical zone is formulated to
release the one or more agrochemicals of the agrochemical zone
gradually over time. In some embodiments, the agrochemical zones
are formulated to release the at least one agrochemical into the
root development zones over a period of at least about one week
when the root development zones are hydrated. In some embodiments,
the agrochemical zones are formulated to release the at least one
agrochemical into the root development zones over a period greater
than one week when the root development zones are hydrated.
"Controlled release" is interchangeable with the term "slow
release" ("SR").
[0462] "DAP" means days after planting.
[0463] Unless required otherwise by context, a "unit" refers to a
unit for delivery of agrochemicals to the roots of a plant as
described herein. A "fertilizer unit" refers to a unit for delivery
of agrochemicals to the roots of a plant as described herein which
comprises a fertilizer.
[0464] An "empty unit" comprises the root development zone
component of a unit of the invention unaccompanied by the
agrochemical zone component. In some embodiments, an empty unit has
the same shape and/or dimensions as the corresponding unit of the
invention.
[0465] A "root development zone" is a component of a unit of the
invention which, when hydrated, can be penetrated by a growing
root. In some embodiments, the growing root can grow and develop
within the root development zone of a unit. In some embodiments, a
root development zone is a super absorbent polymer (SAP). In some
embodiments, the root development zone is an aerogel, a geotextile,
or a sponge. In some embodiments, the root development zone will
take up water from the surrounding environment when, for example,
the unit is placed in soil which is subsequently irrigated. In some
embodiments, the hydrated root development zones create a
artificial environment in which a growing root can uptake water and
nutrients. In some embodiments, the root development zones of a
unit are formulated to contain one or more agrochemicals which are
the same or different than the agrochemicals of the agrochemical
zones of the unit. While the invention described herein is not
limited to any particular mechanism of action, it is believed that
a growing root is attracted to the root development zones of a unit
because of the presence of water and/or agrochemicals (e.g.
minerals) in the root development zones. It is believed that roots
can continue to grow and develop within the root development zones
of units because of the continued availability of water and/or
agrochemicals in the units.
[0466] Use of the term "root development zones" means one or more
root development zones and use of the term "agrochemical zones"
means one or more agrochemical zones unless stated otherwise or
required otherwise by context.
[0467] In some embodiments, a unit of the invention is in the form
of a "bead" having an "external zone" which surrounds an "internal
zone." In some embodiments, the "external zone" is a root
development zone and the "internal zone" is an agrochemical
zone.
[0468] Plants provided by or contemplated for use in embodiments of
the present invention include both monocotyledons and dicotyledons.
In some embodiments, a plant is a crop plant. As used herein, a
"crop plant" is a plant which is grown commercially. In some
embodiments, the plants of the present invention are crop plants
(for example, cereals and pulses, maize, wheat, potatoes, tapioca,
rice, sorghum, millet, cassava, barley, or pea), or other legumes.
In some embodiments, the crop plants may be grown for production of
edible roots, tubers, leaves, stems, flowers or fruit. The plants
may be vegetable or ornamental plants. Non-limiting examples of
crop plants of the invention include: Acrocomia aculeata (macauba
palm), Arabidopsis thaliana, Aracinis hypogaea (peanut),
Astrocaryum murumuru (murumuru), Astrocaryum vulgare (tucuma),
Attalea geraensis (Indaia-rateiro), Attalea humilis (American oil
palm), Attalea oleifera (andaia), Attalea phalerata (uricuri),
Attalea speciosa (babassu), Avena sativa (oats), Beta vulgaris
(sugar beet), Brassica sp. such as Brassica carinata, Brassica
juncea, Brassica napobrassica, Brassica napus (canola), Camelina
sativa (false flax), Cannabis sativa (hemp), Carthamus tinctorius
(safflower), Caryocar brasiliense (pequi), Cocos nucifera
(Coconut), Crambe abyssinica (Abyssinian kale), Cucumis melo
(melon), Elaeis guineensis (African palm), Glycine max (soybean),
Gossypium hirsutum (cotton), Helianthus sp. such as Helianthus
annuus (sunflower), Hordeum vulgare (barley), Jatropha curcas
(physic nut), Joannesia princeps (arara nut-tree), Lemna sp.
(duckweed) such as Lemna aequinoctialis, Lemna disperma, Lemna
ecuadoriensis, Lemna gibba (swollen duckweed), Lemna japonica,
Lemna minor, Lemna minuta, Lemna obscura, Lemna paucicostata, Lemna
perpusilla, Lemna tenera, Lemna trisulca, Lemna turionifera, Lemna
valdiviana, Lemna yungensis, Licania rigida (oiticica), Linum
usitatissimum (flax), Lupinus angustifolius (lupin), Mauritia
flexuosa (buriti palm), Maximiliana maripa (inaja palm), Miscanthus
sp. such as Miscanthus.times.giganteus and Miscanthus sinensis,
Nicotiana sp. (tabacco) such as Nicotiana tabacum or Nicotiana
benthamiana, Oenocarpus bacaba (bacaba-do-azeite), Oenocarpus
bataua (pataua), Oenocarpus distichus (bacaba-de-leque), Oryza sp.
(rice) such as Oryza sativa and Oryza glaberrima, Panicum virgatum
(switchgrass), Paraqueiba paraensis (mari), Persea amencana
(avocado), Pongamia pinnata (Indian beech), Populus trichocarpa,
Ricinus communis (castor), Saccharum sp. (sugarcane), Sesamum
indicum (sesame), Solanum tuberosum (potato), Sorghum sp. such as
Sorghum bicolor, Sorghum vulgare, Theobroma grandifrum (cupuassu),
Trifolium sp, Trithrinax brasiliensis (Brazilian needle palm),
Triticum sp. (wheat) such as Triicum aestivum, Zea mays (corn),
alfalfa (Medicago sativa), rye (Secale cerale), sweet potato
(Lopnoea batatus), cassava (Manihot esculenta), coffee (Cofea
spp.), pineapple (Anana comosus), citris tree (Citrus spp.), cocoa
(Theobroma cacao), tea (Camellia senensis), banana (Musa spp.),
avocado (Persea americana), fig (Ficus casica), guava (Psidium
guajava), mango (Mangifer indica), olive (Olea europaea), papaya
(Carica papaya), cashew (Anacardium occidentale), macadamia
(Macadamia intergrifolia) and almond (Prunus amygdalus).
[0469] Unless stated otherwise or required otherwise by context,
"swelled" means that a material has an absorbed amount of water
which is at least about 1% of the amount of water that would be
absorbed by the material if placed in deionized water for 24 hours
at 21.degree. C. When the material is a hydrogel, a "swelled"
hydrogel can be referred to as a "hydrated" hydrogel. In some
embodiments, a swelled material has an absorbed amount of water
which is at least about 2% of the amount of water that would be
absorbed by the material if placed in deionized water for 24 hours
at 21.degree. C. In some embodiments, a swelled material has an
absorbed amount of water which is at least about 3% of the amount
of water that would be absorbed by the material if placed in
deionized water for 24 hours at 21.degree. C. In some embodiments,
a swelled material has an absorbed amount of water which is at
least about 4% of the amount of water that would be absorbed by the
material if placed in deionized water for 24 hours at 21.degree. C.
In some embodiments, a swelled material has an absorbed amount of
water which is at least about 5% of the amount of water that would
be absorbed by the material if placed in deionized water for 24
hours at 21.degree. C.
[0470] Unless stated otherwise or required otherwise by context,
"hydrated" means at least about 1% hydrated. In some embodiments,
"hydrated" means at least about 2% hydrated. In some embodiments,
"hydrated" means at least about 3% hydrated. In some embodiments,
"hydrated" means at least about 4% hydrated. In some embodiments,
"hydrated" means at least about 5% hydrated.
[0471] As used herein, a "fully swelled" unit of the invention is a
unit which contains an amount of absorbed water which is equal to
the amount of water the unit would absorb if placed in deionized
water for 24 hours at 21.degree. C.
[0472] As used herein, an artificial environment means a media
located within the root zone of an agricultural field or a garden
plant loaded with at least one agrochemical, encourages root growth
and uptake activity within its internal periphery. Non-limiting
examples of agrochemicals include pesticides, including
insecticides, herbicides, and fungicides. Agrochemicals may also
include natural and synthetic fertilizers, hormones and other
chemical growth agents.
[0473] In some embodiments, the medium may comprise multiple
sub-zones, such as: [0474] i) an agrochemical zone (for example, an
Internal Zone); and [0475] ii) a root development zone (for
example, an External Zone).
[0476] In some embodiments, the agrochemical zone is formulated to
release the at least one agrochemical into the root development
zone over a period of at least about one week when the hydrogel of
the root development zone is hydrated. In some embodiments, the
agrochemical zone is formulated to release the at least one
agrochemical into the root development zone over a period of at
least about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, or 20 weeks when the hydrogel of the root development zone
is hydrated. The agrochemical zone may be formulated to control the
release of the at least one agrochemical into the root development
zone by a variety of means described herein. For example, the at
least one agrochemical may be incorporated into a dense polymer in
the core of the agrochemical zone, from which the at least one
agrochemical diffuses when root development zone is hydrated.
Additionally, the core may be coated with a compound or compounds
that slow the rate of the at least one agrochemical's diffusion
into the root development zone. In some embodiments, the coat
compound may diffuse into the root development zone when the root
development zone is hydrated, thereby slowing the rate of the at
least one agrochemical's diffusion into and/or through the root
development zone. In some embodiments, the core comprises a filler
comprising the at least one agrochemical, from which the at least
one agrochemical diffuses. In some embodiments, the at least one
agrochemical diffuses from the core or the filler at a linear rate.
The filler may slow the rate of the at least one agrochemical from
the core. In some embodiments filler may has a physical structure,
such as a beehive-like structure, into which the at least one
agrochemical is incorporated, and from which the at least one
agrochemical slowly diffuses. Bentonite is a non-limiting example
of a filler having a beehive-like structure that is useful in
embodiments of the present invention.
[0477] The agrochemical zone may contain the input (fertilizer or
other agrochemical) in a structure that controls its release into
the root development zone. The release rate is designed to meet
plant demands throughout the growing season. In some embodiments,
no input residuals remain at the end of a predetermined action
period.
[0478] In some embodiments, the agrochemical zone comprises one or
more fertilizers and/or other agrochemicals such as nitrogen,
phosphorus, potassium, fungicide, insecticide, etc., in a beehive
like structure made from highly cross linked polymer coated with
silica or highly cross linked poly acrylic acid/poly sugar with a
clay filler. In some embodiments, the agrochemical zone comprises
fertilizer and/or at least one other agrochemical in a beehive like
structure with or without an external coating.
[0479] In some embodiments, the root development zone is a super
absorbent polymer (SAP) in contact with or surrounding the
agrochemical zone, which attracts the growth and uptake activity of
plant roots. In some embodiments, the root development zone is a
super absorbent polymer-made from CMC-g-poly(acrylic acid)/celite
composite system or modified corn starch cross linked poly (acrylic
acid). A root development zone which surrounds an agrochemical zone
may be referred to herein as a "shell."
[0480] Root development zones of the present invention are
sustainable in soils, and encourage root penetration, uptake
activity, and growth and/or development in the root development
zone. In some embodiments, a super absorbent polymer may serve as
the root development zone since during watering it can absorb soil
moisture, swell and maintain its high water content over long
period of time. These features establish a zone where gradual
transition of chemical concentration exists between the
agrochemical zone to the periphery of the root development zone
allowing root uptake activity during the unit of the invention's
life cycle. In some embodiments, the root development zone has
features such as mechanical resistance (in order to maintain its
shape and geometry in the soil); swelling cycle capability (capable
of repeated hydration and dehydration in response to soil water
content); oxygen permeability--(maintaining sufficient oxygen level
to support root activity, such as root development); and root
penetration (allowing the growth of roots into it).
[0481] Materials that may be used in the present invention include
but are not limited to: 1) clay 2) zeolite 3) tuff 4) fly ash 5)
hydrogel 6) foam.
[0482] In some embodiments, an artificial environment of the
present invention serves as a buffer for soil type and pH to
provide universal root growth environment. In some embodiments, an
artificial environment of the present invention contains needed
materials and nutrients in the desired conditions, such as but not
limited to water, fertilizers, drugs, and other additives.
Oxygen Permeability
[0483] Aspects of the present invention relate to root development
zones having SAPs that are permeable to oxygen when hydrated. Roots
use oxygen for growth and development (Drew, 1997; Hopkins 1950).
Therefore, the oxygen permeability of a SAP is an important factor
in determining whether it will support root growth and development
within a root development zone that comprises the SAP.
[0484] Without wishing to be bound by any scientific theory, since
hydrogels of the present invention supply water, nutrients and weak
resistance, the data hereinbelow show that provided the gas
diffusion is high enough, roots will develop in most types of
small-volume hydrogels and hydrogel containing units, installed in
a field soil. For example, alginate hydrogel, which is suitably
permeable to oxygen, encourages root development, whereas starch
hydrogel, which is poorly permeable to oxygen does not encourage
root development. Additionally, semi-synthetic CMC is also suitably
permeable to oxygen. The ability of oxygen to diffuse into root
development zones of the present invention is important for root
development within them.
[0485] Aspects of the present invention relate to the selection of
SAPs, such as hydrogels, that are sufficiently permeable to oxygen
when hydrated. Oxygen permeability may be measured to determine
whether a hydrated SAP is sufficiently permeable to oxygen for use
in embodiments of the present invention. In some embodiments, the
SAP is permeable to oxygen such that it supports root growth and/or
development. In some embodiments, the SAP when hydrated is at least
about 70, 75, 80, 85, 90, 95, or 100% as permeable to oxygen as
hydrated alginate. In some embodiments, the SAP when hydrated is at
least about 70, 75, 80, 85, 90, 95, or 100% as permeable to oxygen
as hydrated semi-synthetic CMC.
[0486] Oxygen permeability may be measured according to assays that
are well known in the art. Non-limiting examples of methods that
may be useful for measuring oxygen permeability of SAPs of the
invention are described in Aiba et al. (1968) "Rapid Determination
of Oxygen Permeability of Polymer Membranes" Ind. Eng. Chem.
Fundamen., 7(3), pp 497-502; Yasuda and Stone (1962) "Permeability
of Polymer Membranes to Dissolved Oxygen" Cedars-Sinai Medical
Center Los Angeles Calif. Polymer Div, 9 pages, available from
www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=AD0623983;
Erol Ayranci and Sibel Tune (March 2003) "A method for the
measurement of the oxygen permeability and the development of
edible films to reduce the rate of oxidative reactions in fresh
foods" Food Chemistry Volume 80, Issue 3, Pages 423-431; and Compan
et al. (July 2002) "Oxygen permeability of hydrogel contact lenses
with organosilicon moieties" Biomaterials Volume 23, Issue 13,
Pages 2767-2772, the entire contents of each of which are
incorporated herein by reference. The permeability of a SAP may be
measured when it is partially or fully hydrated, e.g. when the SAP
is 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 5-50%
hydrated.
Mechanical Resistance
[0487] In preferred embodiments of the present invention, the root
development zones of a unit of the invention are both i)
sufficiently permeable to oxygen to encourage root growth, and ii)
do not disintegrate in soil. In especially preferred embodiments,
the root development zones of a unit of the invention are
mechanically resistant, i.e., are capable of repeated swelling
cycles in soil without fragmenting in the soil. In particularly
preferred embodiments, all of the SAP of the root development zones
remains part of the root development zones after repeated swelling
cycles.
[0488] Despite alginate's permeability to oxygen, root development
zones consisting of alginate are not suitable in preferred
embodiments of the invention because alginate tends to disintegrate
in soil. However, semi-synthetic CMC, which does not tend to
disintegrate and is capable of repeated swelling cycles without
fragmenting in soil (i.e., is mechanically resistant), is suitable
for use in root development zones in preferred embodiments the
invention.
Implementation of Artificial Environments
[0489] Some embodiments of the present invention comprise the
following phases:
[0490] Phase 1: Banding and incorporating into the upper soil
profile.
[0491] Phase 2: Following watering (rainfall and/or irrigation) the
root development zones (comprising, e.g. a SAP) absorbs moisture
from the soil and swells; water penetrates the coating (if present)
and dissolves the fertilizer and/or other agrochemical(s) which
then diffuse into the root development zones (e.g. towards the
periphery of a bead).
[0492] Phase 3: Roots grow, develop, and remain in the root
development zones where uptake lasts a predetermined period.
Methods for Testing Properties of Root Development Zones
[0493] The following is a non-limiting example of a method that may
be used to test the properties of root development zones (e.g. bead
shells). [0494] Distribute empty units (e.g. shells) of different
sizes in a pot. In some embodiments, empty units of three sizes are
used. The shells may have a dry radius of, e.g., 0.5, 1, 1.5, 2,
2.5, 3, 3.5, 4, 4.5, or 5 cm or a length of, e.g., 0.5, 1, 1.5, 2,
2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, 9, or 10 cm. In some embodiments a
10, 11, 12, 13, 14, 15, 20, 25, or 30 liter pot is used. In some
embodiments the empty units are distributed in the pot with soil.
In some embodiments, the soil is sandy soil. [0495] Monitor the
final size and geometry of the empty units following watering. In
some embodiments, the final geometry is spherical, cylindrical, or
box shaped. [0496] Installing ceramic suction cups to mimic roots
water uptake and applying suction through the syringes. [0497]
Altering watering frequency over time (e.g., from high--few times
per day to low--once a week). [0498] Monitoring the volume of water
in the syringes and water drained from the bottom of the pot over
time.
[0499] The following is another non-limiting example of a method
that may be used to test the properties of root development zones
(e.g. bead shells), [0500] Distribute empty units (e.g. shells) of
one size (base, e.g. on findings from the method described above
phase) in a transparent cell. In some embodiments, the cell is made
of Perspex- and is 60.times.2.times.30 cm). In some embodiments,
the empty units are distributed with soil. In some embodiments, the
soil is sandy soil. [0501] Monitoring root location and empty unit
status. In some embodiments, root location and empty status is
monitored by photography or/and scanning. [0502] Repeat with units
with/without nutrients. [0503] Monitoring roots location to
conclude if roots attract by nutrients or water. [0504] Altering
watering frequency over time (e.g., from high--few times per day to
low--once a week).
Methods for Testing Properties of Units of the Invention
[0505] The following is a non-limiting example of a method that may
be used to test the properties of root development zones (e.g. bead
shells). [0506] Growing a plant in a pot. In some embodiments, the
pot is a 10, 11, 12, 13, 14, 15, 20, 25, or 30 liter pot. [0507]
Installing filter paper cups to monitor concentrations in the root
zone and drainage over time.
[0508] Additionally: [0509] Growing a plant in a transparent cell
with mixture of units (e.g. beads) and soil. In some embodiments,
the soil is sandy soil. [0510] Add dying agents to units which are
sensitive to environmental conditions (e.g., pH, Salinity, or N, P,
and K). [0511] Altering watering frequency over time (e.g. from
high--few times per day to low--once a week).
Super Absorbent Polymers
[0512] Super Absorbent Polymers are polymers that can absorb and
retain extremely large amounts of a liquid relative to their own
mass. Non-limiting examples of SAPs that are useful in embodiments
of the subject invention are described in K. Horie, M. Bairon, R.
B. Fox, J. He, M. Hess, J. Kahovec, T. Kitayama, P. Kubisa, E.
Marechal, W. Mormann, R. F. T. Stepto, D. Tabak, J. Vohlidal, E. S.
Wilks, and W. J. Work (2004). "Definitions of terms relating to
reactions of polymers and to functional polymeric materials (IUPAC
Recommendations 2003)". Pure and Applied Chemistry 76 (4): 889-906;
Kabiri, K. (2003). "Synthesis of fast-swelling superabsorbent
hydrogels: effect of crosslinker type and concentration on porosity
and absorption rate". European Polymer Journal 39 (7): 1341-1348;
"History of Super Absorbent Polymer Chemistry". M2 Polymer
Technologies, Inc. (available from
www.m2polymer.com/html/history_of_superabsorbents.html); "Basics of
Super Absorbent Polymer & Acrylic Acid Chemistry". M2 Polymer
Technologies, Inc. (available from
www.m2polymer.com/html/chemistry_sap.html); Katime Trabanca,
Daniel; Katime Trabanca, Oscar; Katime Amashta, Issa Antonio
(September 2004). Los materiales inteligentes de este milenio: Los
hidrogeles macromoleculares. Sintesis, propiedades y aplicaciones.
(1 ed.). Bilbao: Servicio Editorial de la Universidad del Pais
Vasco (UPVIEHU); and Buchholz, Fredric L; Graham, Andrew T, ed.
(1997). Modern Superabsorbent Polymer Technology (1 ed.), John
Wiley & Sons, the entire contents of each of which are hereby
incorporated herein by reference.
[0513] Non-limiting examples of hydrogels that are useful in
embodiments of the subject invention are described in Mathur et
al., 1996. "Methods for Synthesis of Hydrogel Networks: A Review"
Journal of Macromolecular Science, Part C: Polymer Reviews Volume
36, Issue 2, 405-430; and Kabiri et al., 2010. "Superabsorbent
hydrogel composites and nanocomposites: A review" Volume 32, Issue
2, pages 277-289, the entire contents of each of which are hereby
incorporated herein by reference.
Geotextiles
[0514] Geotextiles are permeable fabrics which are typically used
to prevent the movement of soil or sand when placed in contact with
the ground. Non-limiting examples of geotextiles that are useful in
embodiments of the subject invention are described in U.S. Pat.
Nos. 3,928,696, 4,002,034, 6,315,499, 6,368,024, and 6,632,875, the
entire contents of each of which are hereby incorporated herein by
reference.
Aerogels
[0515] Aerogels are gels formed by the dispersion of air in a
solidified matrix. Non-limiting examples of aerogels that are
useful in embodiments of the subject invention are described in
Aegerter, M., ed. (2011) Aerogels Handbook. Springer, the entire
contents of which is hereby incorporated herein by reference.
Aerochemicals
Fertilizers
[0516] A fertilizer is any organic or inorganic material of natural
or synthetic origin (other than liming materials) that is added to
a plant medium to supply one or more nutrients that promotes growth
of plants.
[0517] Non-limiting examples of fertilizers that are useful in
embodiments of the subject invention are described in Stewart, W.
M.; Dibb, D. W.; Johnston, A. E.; Smyth, T. J. (2005). "The
Contribution of Commercial Fertilizer Nutrients to Food
Production". Agronomy Journal 97: 1-6.; Erisman, Jan Willem; MA
Sutton, J Galloway, Z Klimont, W Winiwarter (October 2008). "How a
century of ammonia synthesis changed the world" Nature Geoscience 1
(10): 636.; G. J. Leigh (2004). The world's greatest fix: a history
of nitrogen and agriculture. Oxford University Press US, pp.
134-139; Glass, Anthony (September 2003). "Nitrogen Use Efficiency
of Crop Plants: Physiological Constraints upon Nitrogen
Absorption". Critical Reviews in Plant Sciences 22 (5): 453; Vance;
Uhde-Stone & Allan (2003), "Phosphorus acquisition and use:
critical adaptations by plants for securing a non renewable
resource". New Phythologist (Blackwell Publishing) 157 (3):
423-447.; Moore, Geoff (2001). Soilguide--A handbook for
understanding and managing agricultural soils. Perth, Western
Australia: Agriculture Western Australia. pp. 161-207; Hitussinger,
Peter; Reiner Lohmiiller, Allan M. Watson (2000). Ullmann's
Encyclopedia of Industrial Chemistry, Volume 18. Weinheim, Germany:
Wiley-VCH Verlag GmbH & Co. KGaA. pp. 249-307.; Carroll and
Salt, Steven B. and Steven D. (2004). Ecology for Gardeners.
Cambridge: Timber Press.; Enwall, Karin; Laurent Philippot, 2 and
Sara Hallin1 (December 2005). "Activity and Composition of the
Denitrifying Bacterial Community Respond Differently to Long-Term
Fertilization". Applied and Environmental Microbiology (American
Society for Microbiology) 71 (2): 8335-8343.; Birkhofera, Klaus; T.
Martijn Bezemerb, c, d, Jaap Bloeme, Michael Bonkowskia, Soren
Christensenf, David Duboisg, Fleming Ekelundf, Andreas
Flie.beta.bachh, Lucie Gunstg, Katarina Hedlundi, Paul Maderh, Juha
Mikolaj, Christophe Robink, Heikki Setalaj, Fabienne Tatin-Frouxk,
Wim H. Van der Puttenb, c and Stefan Scheua (September 2008).
"Long-term organic farming fosters below and aboveground biota:
Implications for soil quality, biological control and
productivity". Soil Biology and Biochemistry (Soil Biology and
Biochemistry) 40 (9): 2297-2308.; Lal, R. (2004). "Soil Carbon
Sequestration Impacts on Global Climate Change and Food Security".
Science (Science (journal)) 304 (5677): 1623-7.; and Zublena, J.
P.; J. V. Baird, J. P. Lilly (June 1991). "SoilFacts--Nutrient
Content of Fertilizer and Organic Materials". North Carolina
Cooperative Extension Service. (available from
www.soil.ncsu.edu/publications/Soilfacts/AG-439-18/), the entire
contents of each of which are hereby incorporated herein by
reference.
[0518] Non-limiting examples of fertilizers which may be useful in
embodiments of the present invention include Ammonium nitrate,
Ammonium sulfate, anhydrous ammonia, calcium nitrate/urea, oxamide,
potassium nitrate, urea, urea sulfate, ammoniated superphosphate,
diammonium phosphate, nitric phosphate, potassium carbonate,
potassium metaphosphate, calcium chloride, magnesium ammonium
phosphate, magnesium sulfate, ammonium sulfate, potassium sulfate,
and others disclosed herein.
[0519] Pesticides
[0520] Pesticides are substances or mixtures of substances capable
of preventing, destroying, repelling or mitigating any pest.
Pesticides include insecticides, nematicides, herbicides and
fungicides.
[0521] Insecticides
[0522] Insecticide are pesticides that are useful against insects,
and include but are not limited to organochloride, organophosphate,
carbamate, pyrethroid, neonicotinoid, and ryanoid,
insecticides.
[0523] Non-limiting examples of insecticides that are useful in
embodiments of the subject invention are described in van Emden H
F, Pealall D B (1996) Beyond Silent Spring, Chapman & Hall,
London, 322 pp; Rosemary A. Cole "Isothiocyanates, nitriles and
thiocyanates as products of autolysis of glucosinolates in
Cruciferae" Phytochemutry, 1976. Vol. 15, pp. 759-762; and Robert
L. Metcalf "Insect Control" in Ullmann's Encyclopedia of Industrial
Chemistry" Wiley-VCH, Weinheim, 2002, the entire contents of each
of which are incorporated herein by reference.
[0524] Nematicides
[0525] Nematicides are pesticides that are useful against
plant-parasitic nematodes.
[0526] Non-limiting examples of nematicides that are useful in
embodiments of the subject invention are described in D. J.
Chitwood, "Nematicides," in Encyclopedia of Agrochemicals (3), pp.
1104-1115, John Wiley & Sons, New York, N.Y., 2003; and S. R.
Gowen, "Chemical control of nematodes: efficiency and
side-effects," in Plant Nematode Problems and their Control in the
Near East Region (FAO Plant Production and Protection Paper--144),
1992, the entire contents of each of which are incorporated herein
by reference.
[0527] Herbicides
[0528] Herbicides are pesticides that are useful against unwanted
plants. Non-limiting examples of herbicides that are useful in
embodiments of the subject invention include 2,4-D, aminopyralid,
atrazine, clopyralid, dicamba, glufosinate ammonium, fluazifop,
fluroxypyr, imazapyr, imazamox, metolachlor, pendimethalin,
picloram, and triclopyr.
[0529] Fungicides
[0530] Fungicides are pesticides that are useful against fungi
and/or fungal spores.
[0531] Non-limiting examples of fungicides that are useful in
embodiments of the subject invention are described in Pesticide
Chemistry and Bioscience edited by G. T Brooks and T. R Roberts.
1999. Published by the Royal Society of Chemistry; Metcalfe, R. J.
et al. (2000) The effect of dose and mobility on the strength of
selection for DMI (sterol demethylation inhibitors) fungicide
resistance in inoculated field experiments. Plant Pathology 49:
546-557; and Sierotzki, Helge (2000) Mode of resistance to
respiration inhibitors at the cytochrome bc1 enzyme complex of
Mycosphaerella fijiensis field isolates Pest Management Science
56:833-841, the entire contents of each of which are incorporated
herein by reference.
[0532] Microelements
[0533] Non-limiting examples of microelements that are useful in
embodiments of the subject invention include iron, manganese,
boron, zinc, copper, molybdenum, chlorine, sodium, cobalt, silicon,
and selenium nickel.
[0534] Hormones
[0535] Plant hormones may be used to affect plant processes.
[0536] Non-limiting examples of plant hormones that are useful in
embodiments of the subject invention include but are not limited
to, auxins (such as heteroauxin and its analogues, indolylbutyric
acid and a-naphthylacetic acid), gibberellins, and cytokinins.
[0537] All publications and other references mentioned herein are
incorporated by reference in their entirety, as if each individual
publication or reference were specifically and individually
indicated to be incorporated by reference. Publications and
references cited herein are not admitted to be prior art.
[0538] This invention will be better understood by reference to the
Experimental Details which follow, but those skilled in the art
will readily appreciate that the specific experiments detailed are
only illustrative of the invention as defined in the claims which
follow thereafter.
EXPERIMENTAL DETAILS
[0539] Examples are provided below to facilitate a more complete
understanding of the invention. The following examples illustrate
the exemplary modes of making and practicing the invention.
However, the scope of the invention is not limited to specific
embodiments disclosed in these Examples, which are for purposes of
illustration only.
Example 1
The External Zone
[0540] Four specific criteria were defined as the following, where
each condition was tested experimentally: [0541] Mechanical
resistance--maintain shape and geometry in the soil [0542] Swelling
cycles--hydrate and dehydrate in corresponds to soil water content
[0543] Oxygen permeability--maintain sufficient oxygen level to
root activity [0544] Root penetration--allows the growth of root
into it.
[0545] Mechanical resistance was tested by flushing water
throughout a container filled with SAP and sand soil, Initial,
final weights and dimensions were recorded. A pass mark was
accepted for SAP that maintains a single element and didn't wash
away or split into several parts. Three groups of SAP were
synthesized and tested:
TABLE-US-00001 SAPs Group Poly sugar Semi synthetic Fully synthetic
Type Alginate CMC-g-poly (acrylic acid)/Celite Acrylic composite
system Carboxymethyl Acid/Acryl cellulose grafted polyacrylics acid
Amide with Celite as a filler. k-Carrageenan poly(acrylic
acid)SAP
[0546] Each type of SAP was formulated with variable mixture of
poly sugars, crosslinked agents, filler and additive. Moreover,
samples were oven dried and immersed in distilled water in order to
calculate the equilibrium swelling (ES) according to the following
equation:
ES = weight of swollen gel - weight of Dried gel weight of Dried
gel ##EQU00001##
[0547] Table 1 summarizes the findings of the mechanical resistance
tests:
TABLE-US-00002 Bis- SAP-Group SAP-type AAm/AA % PS/AA NaOH ES Semi-
CMC 0.75-1.25 50-75 15-25 73-467 synthetic k-Carrageenan 1.6-2.5
33-66 -- 25-72 Poly sugar Alginate-2% -- 100 -- 38 Fully Acrylic --
0 -- 180 synthetic (AA/AM) "Bis-AAm/AA" means (Acrylic acid
crosslinked with Bis acrylamide," "% PS/AA, semi-synthetic
Polysugar - acrylic acid hydrogel" and "ES" means "equilibrium
swelling." "Alginate-2%." means 2% in water when hydrated.
1) Poly Sugar:
[0548] 16 gr of sodium alginate was dissolved in 800 ml distilled
water at 50.degree. C. using mechanical stirrer (1000 RPM). Then 20
gr from the alginate solution was added in to 50 ml beaker, then 10
gr of 0.1 M solution of CaCl.sub.2, was added in to the beaker
(CaCl.sub.2 served as the cross-linking agent). The beads were left
in the solution for 12 hr.
2) CMC-g-Poly (Acrylic Acid)/Celite
[0548] [0549] Various amounts of CMC (Carboxymethyl cellulose
sodium Salt) (0.5-2 g) were dissolved in 25 ml distilled water and
were added to a 100 ml beaker with magnetic stirrer. The beaker was
immersed in a temperature controlled water bath preset at
80.degree. C. After complete dissolution of CMC, various amounts of
Celite powder (0.3-0.6 g in 5 ml water) were added (if any) to the
solution and allowed to stir for 10 min. Then, certain amounts of
AA (Acrylic Acid) (2-3 ml) and MBA (N--N methylene bis acrylamide)
(0.025-0.1 g in 5 ml water) were added to the reaction mixture and
allowed to stir for 5 min. Then the initiator solution (0.07 g APS
(Ammonium persulfate) in 5 ml water) was added to the mixture, the
mixture was placed immersed in a temperature controlled water bath
preset at 85.degree. C. for 40 minutes to complete polymerization.
To neutralize (0-100%) acrylic groups, appropriate amount of NaOH
(0-1 gr in 5 ml water) was added. The obtained gel was poured to
excess nonsolvent ethanol (80 ml) and remained for 1 h. 3)
k-Carrageenan (kC) Cross-Linked-Poly(Acrylic Acid)
[0550] 0.5-1 gr of kC (k-Carrageenan) was dissolved in 25 mL of
distilled water, which was under vigorous stirring in a 100 ml
beaker with a magnetic stirrer. The flask was immersed in a
temperature controlled water bath at 80.degree. C. After complete
dissolution of kC to form a homogeneous solution, certain amounts
of AA (Acrylic Acid), and MBA (N--N methylene his acrylamide)
simultaneously added to the reaction mixture. Afterward, the
solution was stirred and purged with nitrogen for 2 min to remove
the dissolved oxygen. Then, a definite amount of APS (Ammonium
persulfate) solution was added dropwise to the reaction flask under
continuous stirring to generate free radicals. The reaction
maintained at this temperature for 1 h to complete
polymerization.
4) Fully Synthetic System (a Sample for AAm):
[0551] AAm (Acrylamide) (10 g) was mix with 25 ml distilled water
at room temperature in a 50 ml beaker equipped with magnetic
stirrer. Then MBA (N--N methylene his acrylamide) (0.008 gr) was
added into the mixture and allowed to stir for 10 min. Then an
initiator solution was added (0.07 g SPS (Sodium persulfate)). The
mixture was placed into 5 ml template (4 gr solution each) and
placed in a convention furnace (85.degree. C.) for 20 min. The
product was washed overnight with ethanol (80 ml) to obtain the
polymerized shell.
Starch Systems--Sample for Non-Growing Media
1) Modified Starch Cross-Linked Poly(Acrylic Acid)
[0552] 1-2.5 gr of Corn starch dissolved in deionized 20 ml water
in 100 ml beaker at room temperature. The combination was mixed
until a uniform mixture was formed. 2-3 gr AA (Acrylic acid) was
added to the cooled mixture and the resulting mixture was stirred
for five minutes. Next, 1-3 gr AAm (acrylamide) was added to the
mixture, and the resulting mixture was stirred for five minutes.
Then 0.005-0.01 gr of MBA (N--N methylene bis acrylamide) dissolved
in 5 ml of deionized water was added to the mixture, and the
resulting mixture was stirred for five minutes. Lastly, 0.005 gr of
APS (ammonium persulfate) dissolved in 0.5 ml of deionized water;
was added to the mixture and the resulting mixture was stirred
while being heated to 80.degree. C. The mixture was held at that
temperature and stirred for approximately 15 minutes. Because the
resulting viscous mass was acidic, the mixture was neutralized by
titration with 45% potassium hydroxide (KOH) at room temperature.
Titration continued until a pH of 7.0 was reached, which required
addition of between about 0.2-16 g 45% KOH.
2) Similar Process to the CMC-AA System.
[0553] (Exchanging CMC with Corn-Starch): [0554] 1 gr of corn
Starch was dissolved in 25 ml distilled water and were added to a
100 ml beaker with magnetic stirrer. The beaker was immersed in a
temperature controlled water bath preset at 80.degree. C. Then 2 ml
of AA (Acrylic Acid) and MBA (N--N methylene bis acrylamide) (0.015
g in 5 ml water) were added to the reaction mixture and allowed to
stir for 5 min. Then the initiator solution (0.07 g APS (Ammonium
persulfate) in 5 ml water) was added to the mixture, the mixture
was placed immersed in a temperature controlled water bath preset
at 85.degree. C. for 40 minutes to complete polymerization. NaOH
(0.5 gr in 5 ml water) was added in order to neutralize acrylic
groups. The obtained gel was poured to excess nonsolvent ethanol
(80 ml) and remained for 1 h.
[0555] Swelling cycles of selected formulations in water and two
types of soil were tested. The ability of the SAPs to absorb water
in relatively short time is an important physical property that
allows maintaining its functionality in the soil throughout its
life cycle. The following graphs present the swelling behavior of
the different SAPs upon hydration-dehydration cycles in water. The
ES of the investigated SAPs stay constant during three cycles,
meaning good mechanical properties.
[0556] The water content of several SAPs in sandy silica soil was
measured following watering over a time period that is a typical
watering cycle of crops and plants. The various SAPs gain water
from the soil in the first 24 hours following by a mild
decrease/increase over the next 125 hours. When SAPs were
introduced to air dry loess soil, initially it went under rapid de
hydration, yet watering the soil reverse the process and water were
absorbed from the soil the soil recovery percentage were 99 and 50.
The results indicate that all groups of SAPs can maintain their
moisture in the sandy soil over a watering cycle and that CMC base
SAPs can fully recovery from extreme dry condition in soil.
[0557] Oxygen permeability of the SAPs was studied by measuring
dissolved oxygen in water that was exposed to oxygen saturated
water across a SAP, Altering dissolved oxygen level was done by
bubbling nitrogen or oxygen gases into the water reservoir located
opposite the sensor, SAPs made from Alginate and CMC showed an
order magnitude more oxygen permeability than SAP of k-carrageenan
(FIG. 4).
Dissolved Oxygen Test:
[0558] Oxygen electrode place into a pre-swelled hydrogel in a 100
ml beaker. The dissolved oxygen inside the hydrogel was measured
during N.sub.2 bubbling or O.sub.2 bubbling (.about.0.5 liter per
minute) as a function of time.
[0559] The O.sub.2 measurements made by Lutron WA2017SD Analyzer
with dissolved oxygen probe 0-20 mg/L, 0-50.degree. C. The
Dissolved Oxygen System is shown in FIG. 13.
[0560] Root penetration was evaluated visually from a series of
experiments, where various crops grew in pots filled with organic
soil surrounded an artificial environment. Table 2 summarizes the
observations presented in FIG. 10:
TABLE-US-00003 Roots Roots Roots on the penetrated developed
surface of into in the artificial the artificial artificial SAPs
Crop environment environment environment Poly Sugar- Pea - + +
Alginate Semi synthetic- Corn, Pea, + + - CMC Semi synthetic- Pea +
+ - k-Carrageenan Fully synthetic Corn + + -
Example 2
The Internal zone
[0561] Three mechanisms were developed and evaluated to address the
criteria of i) release rate of agrochemicals from the internal zone
over a growing season, and ii) that no input residuals remain at
the end of a predetermined action period. All the three, are based
on integrating the input into a very dense polymer as the basic
mechanism to slow down diffusion, in conjunction to a secondary
mechanism that will additionally decrease the diffusion rate:
[0562] 1) Highly Cross Linked Polymer with silicon coating
(xLP-Si); [0563] 2) Highly Cross linked Poly Acrylic/poly sugar
with filler (xLP-F); and [0564] 3) Hybrid system (SiCLP-).
[0565] The first mechanism is based on precipitation of silica,
originated from silica water, on the surface of the polymer (FIG.
4).
[0566] The second mechanism is based on filler, made from
bentonite, integrated into the polymer and decreases sharply its
diffusion properties (FIG. 6).
[0567] The third mechanism is to mix the silica with the acrylic
while synthesizing the polymer in order to alter its diffusion
coefficient (FIG. 7).
[0568] The reduction in diffusion properties by each mechanism was
experimentally tested. The internal zone was located in a free
water reservoir where the concentration of a certain input
(Nitrogen or Phosphorus) was measured over time.
[0569] The release of nitrate from cornstarch internal zone with
(blue) and without (red) silica coating is presented in FIG. 7. A
reduction of diffused nitrate was measured in the first 24
hours.
[0570] Alternatively, the mixed silica mechanism yielded release of
nitrate and phosphorus in the scale of weeks, as well.
Example 3
Stability, Dimensions, and Mechanical Resistance of Hydrogels
Applied to a Field Plot
Objective
[0571] The objective of this example was to study the
sustainability in soil, hydrated dimensions and mechanical
resistance of different types and sizes of hydrogel within a field
plot. Furthermore, root penetration into these types of hydrogels
was studied.
Hydrogels
[0572] The types and sizes of hydrogels are described in Table 3
below:
TABLE-US-00004 Small Medium Large (hydrated (hydrated size
(hydrated size No. Chemical composition size of 2-3 cm) of 4-5 cm)
of 7-8 cm) Geometry 1 Fully synthetic + Box 2 Semisynthetic CMC 6%
+ + + Cylinder/Box/Cylinder AAm 3 Semisynthetic CMC 6% AA + Box 4
Semisynthetic CMC 25% + Box AA 5 Semisynthetic CMC 50% + + +
Cylinder/Box/Cylinder AA 6 Polysugars Alginate + Cylinder
[0573] The fully synthetic hydrogel had the composition of the
fully synthetic hydrogel described in Example 1.
[0574] The semisynthetic CMC 6% AAm hydrogel comprises 6% CMC
relative to the acrylic acid monomers (Acrylamide-acrylic) and was
made by the following process. 0.25 g AA was mixed with 4.5 ml
distilled water at room temperature in a 50 ml beaker equipped with
a magnetic stirrer. Then 0.1 g NaOH, 0.01 g MBA, 0.75 g AAm and 1.5
gr CMC solution (3.8% w/w) were added into the mixture and allowed
to stir for 10 minutes. Then an initiator solution comprising 0.1 g
SPS was added. The mixture was placed into a 5 ml template (4 g
solution for each shell) and placed in a convention furnace at
85.degree. C. for 20 minutes. The product was washed overnight with
80 ml ethanol to obtain the polymerized shell.
[0575] The semisynthetic CMC 6% AA hydrogel comprises 6% CMC
relative to acrylic acid and was made by the following process. 1 g
AA was mixed with 4.5 ml distilled water at room temperature in a
50 ml beaker equipped with magnetic stirrer. Then 0.4 g NaOH, 0.01
g MBA and 1.5 g CMC solution (3.8% w/w) were added to the reaction
mixture and allowed to stir for 10 minutes. Then 0.1 g of SPS was
added. The mixture was added into a 5 ml template (4 g solution for
each shell), and the template was placed in a convention furnace at
85.degree. C. for 20 minutes. The product was washed overnight with
80 ml ethanol to obtain the polymerized shell.
[0576] The semisynthetic CMC 25% AA hydrogel comprises 25% CMC
relative to acrylic acid and was made by the following process. 2 g
AA was mixed with 12.5 g CMC solution (3.8% w/w) at room
temperature in a 50 ml beaker equipped with magnetic stirrer. Then
0.01 g MBA was added into the mixture and allowed to stir for 10
minutes. Then an initiator solution comprising 0.1 g SPS was added.
The mixture was placed into 5 ml template (4 gr solution for each
shell), and the template was placed in a convention furnace at
85.degree. C. for 20 min. Then NaOH (0.728 molar ratio or 0.8 gr in
50 ml water) was added to the polymerization product. The product
was then washed overnight with 80 ml ethanol to obtain the
polymerized shell.
[0577] The semisynthetic CMC 50% AA hydrogel comprises 50% CMC
relative to acrylic acid and was made by the following process. 1.5
g CMC were dissolved in 35 ml distilled water and added to a 100 ml
beaker with magnetic stirrer. The beaker was immersed in a
temperature controlled water bath preset at 85.degree. C. After
complete dissolution of CMC, the beaker was placed on a magnetic
stirrer at room temperature with N.sub.2 bubbling at a flow rate of
.about.0.5 LPM. Then 3 g AA and 0.03 g MBA were added to the
reaction mixture and allowed to stir for 20 minutes and the
temperature was allowed to decrease to 35.degree. C. Then the 0.03
g of the initiator SPS in 1 ml water was added. The mixture was
placed into 5 ml template (4 g solution for each shell) and placed
in furnace at 85.degree. C. for 20 minutes. Then NaOH (0.728 molar
ratio or 0.8 gr in 50 ml water) was added to the polymerization
product. The product was then washed overnight with 80 ml ethanol
to obtain the polymerized shell.
[0578] The polysugars alginate hydrogel had the composition of the
polysugar hydrogel described in Example 1.
Experimental Setup
[0579] The experiment took place at the Southern Arava R&D
station. A 125 square meters field plot, divided to 4 beds.times.15
m long was served to test 3 application methods, six types and
three sizes of hydrogels. Root penetration was studied in plot
D.
[0580] The experimental setup is shown in FIG. 14.
[0581] The three application conditions for plots A-C were:
i) Uniform application in loose soil--to mimic conventional beds
for vegetable crops; ii) Uniform application in compacted soil--to
mimic conventional beds for vegetable crops, with compaction; and
iii) Application in a furrow--to mimic a furrow in field row
crops.
[0582] A one square meter or one linear meter sub plots (50 cm
apart) were used to apply 27 units of each hydrogel (plots A-C).
The units were uniformly distributed on the soil surface and
incorporated into the upper 15 cm of the soil profile. Similarly, a
20 cm deep furrow was dug and 27 units were distributed along one
meter. Water was applied through a solid sprinkler set without
fertilizer (1 m.sup.3=8 mm).
[0583] The roots penetration plot (plot D) consisted of a 15 m long
bed, where 25 hydrogels from each type were applied along a 1 m
furrow of 20 cm deep. Maize was sown above the at the same day and
was irrigated with a solid set of sprinklers without fertilizes,
that was switched after germination to a drip line (25 cm spacing,
2 l/h) with Idit liquid fertilizer (100 mg/l N). Irrigation was
shut off on day 31 and was opened again one day before soil
excavation. Visual dimensional measurements and qualitative
information on root penetration were collected on day 50.
[0584] Measurements included individual weight, dimension and
tension of 3 units. Timing of water application to plots A-C and
measurements are shown in Table 4 below:
TABLE-US-00005 Day Irrigation (mm) Measurements 0 Application 1 160
2 1.sup.st 5 40 6 2.sup.nd 8 40 12 40 3.sup.rd (before irrigation)
16 4.sup.th 29 5.sup.th
[0585] Climate during the experiment was clear sky with no
rainfall. Maximum and minimum soil temperatures at 5 cm depth
during the experiment period are presented in FIG. 15. The
hydrogels were exposed to temperatures which ranged between
10.degree. C. at night to 40.degree. C. around midday.
Results for Plots A-C
[0586] Changes in weight for each hydrogel type and size versus
time are shown in FIG. 16. The variable soil moisture was derived
by the irrigation events (vertical bars). During the wetting phase,
comprising of four consecutive irrigations (day-12), most of the
hydrogels gained weight by absorbing soil water. The poly sugar
Alginate was the only type to lose weight throughout the
experiment, although soil moisture fluctuated between very wet to
mild dry soil. While medium and large hydrogels multiplied their
own weight (equal to the amount of absorbed soil water) by 5-11
times, the small hydrogel grew by 18 times. During the 16 days
drying phase, hydrogels lost weight by 2-4 times (of the original
weight) to the drying soil. No correlation between CMC percentage
and water absorbance was found. This may imply that local
conditions are more dominant than chemical composition.
[0587] The final surface area derived from the volume and the
geometry of the hydrogels is shown in FIG. 17. Initial areas ranged
between 25-30 cm.sup.2 for medium size, 35 cm.sup.2 for large size
and 10 cm.sup.2 for small size. Most medium hydrogels experienced a
minor increase, up to 35 cm.sup.2, while Alginate decreased sharply
and Semisynthetic CMC 50% AA (no. 5) increased dramatically to 60
cm.sup.2. The two large sizes increased to over 50 cm.sup.2.
Surface area of hydrogel units versus time is shown in FIG. 18.
[0588] The ratio between surface areas to volume was constant to
most hydrogels at the value of 2.5-3. The poly sugar Alginate and
both small size hydrogels had high ratio due to their relatively
small dimensions. Surface area to volume ratios for the hydrogels
are shown in FIG. 19.
[0589] The distance between a chemical (positioned inside the
hydrogel) and the adjacent soil determines the diffusion rates
towards the soil. The minimal distance stands for the smallest edge
of the hydrogel geometry. Moreover, the same value describes the
potential zone for root growth. The initial minimal distance was in
the range of 1-2 cm and final values increased to 1.5-2.5 cm. This
entails that a chemical will need to diffuse 1-2 cm prior to
reaching the soil. The poly sugar Alginate shrunk over time,
reaching 0.5 cm in width. The small size hydrogel was difficult to
follow, yet it stretched to 0.75 cm. Final minimal distances of the
hydrogels are shown in FIG. 20. FIG. 21 shows the minimal distance
of hydrogel units versus time.
[0590] Stiffness is an important parameter related to the potential
of roots to penetrate the media and the potential of water to be
absorbed. Measurements of stiffness were achieved by using a
penetrometer gauge and a metal disc. The values shown in FIGS. 22
and 23 are in relative scale, representing the force that was
required to push the disc on the surface of the hydrogel. No
differences between medium and large sizes were found. The poly
sugar Alginate was consistently very stiff throughout the
experiments, contrary to the fully synthetic, which was relatively
flexible. A negative trend between CMC content and level of
stiffness was observed.
[0591] A photo of each hydrogel at the end of the experiment is
shown in FIG. 24. The Fully synthetic, Semisynthetic CMC 6% AAm,
Semisynthetic CMC 25% AA maintained the original box shape.
Similarly, Semisynthetic CMC 6% AAm-Large, Semisynthetic CMC 50%
AA-Large and Semisynthetic CMC 6% AAm-Small maintained the
cylindrical geometry. Several hydrogels, made from Semisynthetic
CMC 6% AA, disintegrated into small particles. Semisynthetic CMC
50% AA lost its original box geometry and turned into an undefined
geometry. The poly sugars Alginate turned into a flat disc.
Results for Plot D
[0592] Hydrogels nos. 6, 9 and 10 could not be found in the root
zone at the end of the experiment. Photos of each hydrogel type at
the end of the experiment are shown in FIG. 25. The left photo
shows the hydrogels in-situ and the right shows a few samples where
roots penetrated through it. Fully synthetic, Semisynthetic CMC 6%
AAm, and Semisynthetic CMC 25% AA maintained the original box
shape. Similarly, Semisynthetic CMC 6% AAm-Large and Semisynthetic
CMC 50% AA-Large maintained their cylindrical geometry. Several
hydrogels, made from Semisynthetic CMC 6% AA, disintegrated into
small particles. Semisynthetic CMC 50% AA lost its original box
geometry and turned into an undefined geometry. All types of
hydrogel experienced shrinkage relative to its maximum volume
measured in the bare soil plots. Roots penetrated into all types of
hydrogels. While course roots penetrated into the Fully synthetic,
Semisynthetic CMC 25% AA and Semisynthetic CMC 50% AA hydrogels,
only fine roots were found in the Semisynthetic CMC 6% AAm,
Semisynthetic CMC 6% AA and Semisynthetic CMC 6% AAm-Large.
Summary
[0593] Six types and three sizes of hydrogels were tested in a
field plot during wetting and drying periods. Most of them were in
accordance with soil moisture, absorbing water (up to 10 times
their initial weight) in the first period and releasing water in
the second one. Final surface area was 30-50 cm.sup.2. The minimal
dimension of the medium and large hydrogels was 1.5-2.5 cm,
allowing sufficient volume for root penetration. Small hydrogels
expanded to less than 1 cm, which would constrain the amount of
chemicals which could be encapsulated within the hydrogel.
Stiffness was evaluated and a major difference was found between
hydrogel types. While most types maintained their original 3D
geometry, a few disintegrated or deformed.
[0594] Six types and three sizes of hydrogels were evaluated in a
field plot for root penetration. Most types maintained their
original 3D geometry, yet a few disintegrated, deformed or flushed
away. Roots penetrated into all hydrogels, but a few types had only
fine roots while others had fine and course roots. The amount of
root penetration and development observed in the different size
hydrogels suggests that a minimum volume of hydrogel is required
for root penetration and development.
Example 4
Performance of Hydrogels Loaded with Fertilizer in Different Soil
Types
[0595] Example 3 demonstrated the ability of hydrogels to sustain
in the field soil under wet and drying cycles. Moreover, roots
penetrated into the hydrogels suggesting the potential use to
deliver chemicals directly to roots. Current practices to deliver
fertilizers to the plant roots mostly involve application of
fertilizers to the soil, a highly variable media (physically,
chemically and biologically). Such practices yield low efficiency
of fertilizer uptake.
Objective
[0596] The primary objective was to study the effectiveness of
hydrogels loaded with fertilizer (fertilizer units) to supply plant
uptake requirements throughout the growing season. The secondary
objective was to test the development of fine roots, dominant in
mineral uptake, within the hydrogel.
Fertilizer Units
[0597] The composition of the fertilizer units of Example 4 was as
shown in Table 5:
TABLE-US-00006 % w/w Fertilizer units - composition Osmocote .RTM.
Start 6 Weeks 14% Polymer 86% Polymer composition Acrylic Acid 3%
Acryl-Amide 8% CarboxyMethyl Cellulose sodium <1% salt Sodium
Persulfate 1% N--N methylene bis acrylamide <1% Water 74%
Experimental Setup
[0598] The experiment took place at the Southern Arava R&D
station. Twenty three rotating weighing lysimeters (FIG. 26) served
to test the fertilizer units versus fertigation (Fert.) and slow
release fertilizer (SR, Osmocote.RTM. Start 6 Weeks, Everris). The
system allowed accurate monitoring of quantity and quality of
irrigation and drainage water and plant water uptake. Fertilizer
units, containing 0.625 g of the slow release fertilizer (N:P:K
ratio by weight was 12:4.8:14.1+micronutrients), were distributed
evenly at three depths: 30, 20 and 10 cm (FIG. 27). Total weight of
each unit during application was 6-7 g.
[0599] Sunflowers were used as a model plant. Two sunflowers were
grown in each lysimeter. The lysimeters were irrigated daily (clay
soil-twice a week) at an average rate of 200% of measured actual
Evapotranspiration (ET). The high leaching factor was designed to
minimize drought and salinity effects.
[0600] The experiment was divided into three stages:
[0601] Stage 1: Comparing the application of slow released
fertilizer to fertilizer units.
[0602] Stage 2: Separating between water and fertilizer effect on
plant development.
[0603] Stage 3: Evaluating the fertilizer unit performance in
different soil types.
[0604] The experimental setup is shown in Table 6:
TABLE-US-00007 Fertilizing Fertilizing rate vs. plant Lysimeters
soil technology requirement nos. Note Stage Dune fertilizer unit
100% (Full) 12, 13, 14 90 fertilizer 1 sand units fertilizer unit
50% (Half) 15, 16, 17 45 fertilizer units SR 100% (Full) 4, 5, 6
None Stage Dune fertilizer unit 100% (Full) 9, 10 45 fertilizer 2
sand units Empty unit + 100% (Full) 7, 8 45 Empty Fert. units Stage
Grow- fertilizer unit 100% (Full) 1 45 fertilizer 3 ing unit Media
SR 100% (Full) 21 45 fertilizer units Clay fertilizer unit 100%
(Full) 18 45 fertilizer units SR 100% (Full) 3 45 fertilizer
units
Stage 1
[0605] The sunflowers were sown on day 0 and harvested on day 33.
Dune sand was selected due to its inerratic properties, minimizing
adsorption to clay minerals and precipitation due to low
bicarbonate content. Application dose of N, P and K per plant for
each treatment is depicted in FIG. 28. Plant height, no. of leaves,
Soil Plant Analysis Development (SPAD) values and NPK in drainage
water were recorded at points during the growing season. Final
yield quantification included dry biomass and NPK content of the
whole plant. Following harvest, the fertilizer units were excavated
and NPK content was quantified.
Stage 2
[0606] The sunflowers were sown on day 0 and harvested on day 36.
Application dose of N, P and K per plant for each treatment was
half of the values depicted in FIG. 28. Plant height, no. of
leaves, SPAD values were recorded at points during the growing
season. Final yield was evaluated as wet biomass.
Results
Stage 1
[0607] Plant height, number of leaves and its N content,
represented by SPAD values, throughout the growing season are
presented in FIG. 29.
[0608] Differences in height and leaves between the fertilizer
units and SR started from the beginning of the growing season and
continued till the end (see FIG. 35). SPAD values were higher
during the main nutrient application period (DAP 20-45). The lower
SPAD values measured at the end of the growing season for
fertilizer unit treatment were attributed to earlier maturity,
where nutrients are being transferred from the leaves to the
seeds.
[0609] Plant dry matter, absolute NPK uptake amount and its
efficiency are presented in FIG. 30. The fertilizer units yielded
larger plants and NPK uptake versus the Slow Release fertilizer.
Within the fertilizer unit treatment, the full fertilization
achieved higher plants and uptake, yet the efficiency was equal.
The greatest fertilizer use efficiency of the fertilizer unit
demonstrates the advantage of the new technology over current best
practices.
[0610] Relative residuals of NPK in the fertilizer units are
depicted in FIG. 31. The lower values, less than 6%, indicate that
most of the fertilizer was taken up by the plant or diffused to the
soil.
Stage 2
[0611] The dune sand, used in stage 1, has a low water holding
capacity and high hydraulic conductivity, meaning that daily
irrigation may not optimize day time plant water availability. The
hydrogel's shell has the potential to improve water availability by
absorbing water during irrigation and release it later at dry
periods. Therefore, it was possible that the significant
differences found in stage 1 could relate to two factors, namely
fertilizers and water availability. Therefore, a comparison between
fertilizer units and empty fertilizer units installed in the root
zone & fertigation (Empty units+Fert.) was conducted in stage
2.
[0612] Plant height, no. of leaves, SPAD value along the growing
season and wet biomass from each treatment are presented in FIG.
32. Plants exposed to fertilizer units were advantageous over empty
units+Fert at all parameters (see FIG. 35), suggesting that water
availability plays a minor role relative to fertilizer supply under
the experimental conditions. Plants which were fertilized by
fertilizer units exhibited faster growth and enhanced biomass
production.
Stage 3
[0613] The main drawbacks the invention overcomes in soils are:
[0614] Diminishing leaching, adsorption and precipitation of ions.
[0615] Maintaining high diffusion rate at variable moisture
conditions. [0616] Minimizing root growth resistance. [0617]
Allowing continuous biological activity. [0618] Improving water
holding capacity.
[0619] These drawbacks can be overcome by replacing the soil with
growing media, which is considered to provide the best conditions
for plant growth. This hypothesis was tested by comparing the
fertilizer units, SR and Fert. fertilization methods. The
performance of fertilizer units in heavy clayey soil was tested at
the 3rd stage.
[0620] Plant height, no. of leaves, SPAD value along the growing
season and wet biomass for each treatment are presented in FIG. 33.
No significant differences were measured between treatments (see
FIG. 35), suggesting that growing media generates similar
properties as fertilizer units.
[0621] Plant height, no. of leaves, SPAD value along the growing
season and wet biomass for each treatment are presented in FIG. 34.
Visual results of Example 4 are shown in FIG. 35. Fertilizer units
improved plant growth compared to SR (see FIG. 35), demonstrating
that fertilizer units are advantageous in various soil types.
Summary
[0622] The study demonstrated the ability of the fertilizer units
to deliver nutrients to plants throughout the growing season in
various soils. Moreover, fertilizer units enhanced plant growth and
final yield. The higher fertilizer use efficiency over current
practice was due to various reasons: [0623] Extensive growth of
active roots adjacent to the fertilizer source (See FIG. 35).
[0624] Limited leaching from the fertilizer unit due to lack of
mass flow across it. [0625] Maintaining high diffusion rates within
the fertilizer unit in drying soil due to steady high moisture
levels (unlike soil).
[0626] Since the release rate of the fertilizer in this experiment
was temperature dependent, the extreme high temperature which
existed in the soil (average max. soil temp of 45.3.degree. C.)
enhanced the diffusion rate and therefore the absolute efficiency
values were relatively low (FIG. 30).
[0627] Roots did not penetrate empty units, probably due to a lack
of fertilizer within the hydrogel and sufficient moisture for plant
uptake.
[0628] The uptake efficiency shown in FIG. 30 represents the ratio
between the amount of fertilizer applied to the amount taken up by
the plant. The higher uptake efficiency values observed for the
fertilizer units compared to traditional SR fertilizer (FIG. 30)
suggests that less leaching of fertilizer towards groundwater
occurs when fertilizer is applied using fertilizer units.
Example 5
Comparison of Fertilizer Units to Slow Released Fertilizer and
Fertigation in Sunflower and Cabbage
Objective
[0629] The objective was to study the effectiveness of hydrogel
loaded with SR fertilizer (fertilizer units) as a method of
supplying plant nutritional requirements throughout the growing
season under field conditions.
Experimental Setup
[0630] The experiment took place in a field plot located in the
Western Galilee in Israel (N 33, E55). The site is characterized
with heavy alluvial soil, rich in clay minerals, which induces high
cation exchange capacity (.apprxeq.50 meq/100 g), high pH
(.apprxeq.8) and intermediate salinity salinity (EC of saturated
paste-0.5 dS/m). Dry weather conditions with mostly clear skies
(average direct radiation--670 W/m.sup.2) were prevalent throughout
the experiment. Maximum and minimum air and soil temperatures,
midday relative humidity and day time during the trial are
presented in Table 7:
TABLE-US-00008 Max. Min. Air temp. (.degree. C.) 34.2-24.5
34.2-24.5 Soil temp. (.degree. C.) 32.1-11.4 Midday Relative
humidity (%) 71-12 Day time (hh:mm) 13:41-10:29
[0631] A 150 square meter plot was divided into subplots based on
randomized block design (FIG. 36). To ensure initial low levels of
soil nitrogen (N), millet was grown on the field plot without
complementary fertilization for 30 days prior to trial initiation.
The fertilizer units were compared to fertigation (Fert.--Urea
based) and to slow released fertilizer application (SR,
Osmocote.RTM. Start 6 Weeks, Everris). Equal irrigation and N
quantities were applied to all treatments. Nitrogen application
rates were based on literature values, where cabbage was reported
to utilize 3.6 g of N per plant and sunflower was reported to
utilize 3 g of N per plant. Plants were irrigated twice a week
based on ET measurements and literature values for plant cover
coefficient. Irrigation of sunflowers was ceased two weeks prior
harvesting. The crops were planted on day 0 with planting densities
of 40,000 plants per hectare. The cabbage was harvested on day 70
and sunflower was harvested on day 89.
[0632] The monitoring plan (Table 8) included plant development
parameters throughout the growing season and final yield analysis.
Data was collected from pre-marked plants, six plants in the middle
row (cabbage) and 6-10 plants which exhibited similar development
stage after two weeks (sunflower).
TABLE-US-00009 TABLE 8 Developing Yield Crop Pre-plant parameters
analysis Post-harvest Cabbage Soil NPK Plant diameter Wet weight of
Soil N content* head and leaves content* No. of leaves Dry weight
of head and leaves Head diameter N content in head and leaves***
Sunflower NPK content in leaves Plant height Wet weight of flower
and leaves No. of leaves Dry weight of flower and leaves Flower N
content in diameter flower*** SPAD values** Weight of dry seeds NPK
content in leaves *SM3500K and SM4500P-NO; ** Chlorophyll content
optical sensor- Minolta, SPAD 502B; ***kjeldahl-colorimetric
Fertilizer Application
[0633] Fertilizer units, weighing 6-7 g and containing 1 g of SR
(N:P:K ratio by weight was 12:4.8:14.1+micronutrients), were evenly
distributed at two depths: 25 and 15 cm. Total fertilizer unit
application was 80 units (80 grams) per meter length for the
cabbage and 100 for sunflower. SR was distributed evenly at similar
rates and depth. The cabbage fertigation treatment was set to
weekly applications of Urea-N with irrigation water, following a
predetermined plan base on literature values of plant N
requirement. The sunflower fertigation treatment was executed
similarly, with the total plant N requirement applied during the
first two weeks.
Results
[0634] Averages and standard deviations (fertilizer units only) of
sunflower height, cabbage leaf diameter, number of leaves and SPAD
values (sunflower only) throughout the growing season are presented
in FIG. 37. Differences were measured between the fertilizer units,
SR and fertigation treatments in height, diameter, leaf number and
SPAD (see Table 9) at variable stages and maintained until the end.
The improved parameters suggested enhanced growth conditions under
fertilizer unit application for both crops.
TABLE-US-00010 TABLE 9 Statistical groups (Anova) Fertilizing
method Crop Parameter fertilizer unit SR Fert. P Sunflower Height A
A A 0.562 Leaves A B B <0.001 SPAD A B B <0.001 Grains yield
A A A 0.537 N uptake A A A 0.696 Cabbage Leaves A B B 0.005
diameter Leaves A B B 0.005 Yield A B AB 0.242 Biomass A AB B 0.005
N uptake A A B 0.004
[0635] Leaf nutrient content was measured at 55 days after
planting, where both crops finalized their vegetative growth. No
significant differences were found between treatments. Plants under
fertilizer unit application did not exhibit nutritional
deficiencies relative to traditional fertilizer application methods
at this stage of growth (FIG. 38).
[0636] The development of cabbage yields (FIG. 39B) was evaluated
from the linear ratio between head diameter and its weight (FIG.
39A). The advantage of the fertilizer unit application was most
noticeable 60-70 days after planting.
[0637] Final yield analysis of cabbage biomass and N uptake for
fertilizer unit versus conventional fertilizer application methods
is shown in FIG. 40, Significant differences were measured between
the fertilizer unit and fertigation treatments, implying that
nutrients are less available for plant uptake using conventional
fertilizing methods.
[0638] The final yield analysis of sunflower showed similar grain
yield and N uptake by plants fertilized by the fertilizer unit
application method relative to conventional fertilizer application
methods (FIG. 41). Although no significant difference was measured,
plants exposed to fertilizer units uptake more N than plants
exposed to conventional fertilizing methods.
[0639] Residuals of NPK in 10 fertilizer units from each plot are
depicted in FIG. 42. Nitrogen residuals were less than 2%, P less
than 8% and K Less than 2.5%. These values indicate that most of
the fertilizer was taken up by the plants or diffused into the
soil.
[0640] Residuals of N in the root zone (upper 30 cm of soil
profile) of each crop are presented in FIG. 43. Nitrogen
accumulation in the root zone was tenfold higher in the sunflower
plots and 4 times higher in the cabbage plots.
[0641] Nitrogen mass balance was calculated in the root zones of
cabbage and sunflower (FIG. 44). Fertilizer units exhibited higher
N uptake efficiency over conventional fertilizing techniques,
suggesting enhanced availability of fertilizers to plant uptake
within the fertilizer units.
Summary
[0642] This study demonstrated the ability of the fertilizer units
to deliver nutrients to plants throughout the growing season under
normal field conditions. Moreover, fertilizer units enhanced plant
growth (sunflower and cabbage) and increased the final yield
(especially cabbage) compared to current practice. The higher N use
efficiency over current practices is attributed to the following
reasons: [0643] 1. Extensive growth of active roots adjacent to the
fertilizer source (determined visually). [0644] 2. Limited leaching
from the fertilizer units due to lack of water flow across it.
[0645] 3. Maintaining high diffusion-dispersion rates within the
fertilizer units in drying soil due to steady high moisture levels
over time (unlike soil).
Example 6
Pilot Scale Production of Fertilizer Units Based on AA-AAm-CMC
Hydrogels with Onsmocote.RTM. 6 Weeks Cores
[0646] This Example describes the production of fertilizer units
useful in the methods of the invention.
Materials
[0647] Acrylic Acid (AA) (Sigma Aldrich catalog #147230)
[0648] Acrylamide (AAm) (Acros catalog #164830025)
[0649] N--N methylene his acrylamide (MBA) (Sigma Aldrich catalog
#146072)
[0650] Carboxymethylcellulose Sodium salt MW=90K (CMC) (Sigma
Aldrich catalog #419273)
[0651] Sodium persulfate (SPS) (Sigma Aldrich catalog #216232)
[0652] Deionized water (DIW)
[0653] Osmocote.RTM. start 11-11-17+2MgO+TE, Everris International
B.V. (Scott).
Methods
[0654] 8 kg of a 3.8% w/w CMC stock solution is made by slowly
adding 304 g of CMC powder to 7,696 g of 90.degree. C. DIW followed
by stirring for 12 hours at 50.degree. C. Additional DIW is added
to replace any water which evaporates during the 12 hours of
stirring.
[0655] 12 kg of a pre-monomer solution is made by first making an
AA solution by slowly adding 336 g of AA to 5,990 g of DIW, then
adding 384 g of KOH 50% (w/w) solution, and mixing the solution for
15 minutes at 36.degree. C. and pH 4.7. 1,009 g of AAm and 10.09 g
MBA is then added to the AA solution and mixed for 15 minutes.
4,238 g of a 3.8% CMC stock solution is then added to the solution
and the solution is mixed for 30 minutes to provide the pre-monomer
solution.
[0656] 2 L of a monomer solution with initiator is made by adding
4.5 g of SPS into 2 kg of the pre-monomer solution and mixed for 20
minutes.
[0657] The fertilizer units are made in two polymerization steps.
In the first step, a bowl-like hydrogel structure is made by adding
4 ml of the monomer solution to a beads pattern using a multi-tip
dosing devise. The beads pattern is then covered with a cones
matrix and placed in a furnace at 85.degree. C. for 60 minutes,
thereby forming the bowl-like hydrogel structure. 1 g of
Osmocote.RTM. beads are then added to the bowl-like structures. In
the second polymerization step, an additional 3.5 ml of monomer
solution is added to the beads pattern using the multi-tip dosing
device. The beads pattern is then placed in a furnace at 85.degree.
C. for 60 minutes, thereby forming the complete fertilizer
unit.
[0658] The fertilizer units are removed from the beads pattern and
washed with ethanol for 10 minutes (50 beads in 1 L ethanol). The
fertilizer units are then washed with water for 10 minutes (50
beads in 1 L ethanol). The fertilizer units are then dried at room
temperature to a final weight of 3.5-4 g. Beads produced using the
above process are shown in FIG. 46.
[0659] A bead produced using the above process swells to 90-100 g
when placed in 200 ml DIW for 24 hours and swells to 35-50 g when
placed in 200 ml saline water (0.45% NaCl by weight) for 24 hours.
FIG. 47 shows a fully swelled fertilizer unit produced by the above
process compared to a fully dried fertilizer unit.
Example 7
Performance of Fertilizer Units Under Low Ambient Temperature
Growth Conditions
Objective
[0660] The objective was to determine the ability of fertilizer
units to improve plant survival under low ambient temperatures.
Experimental Setup
[0661] Fertilizer units similar to those described in Example 6
were added at depths of 10 and 20 cm to 80 L pots filled with sand
and clay soils. Cucumber plants were grown in the pots for 63 days
within a net house. Control plants were grown under same conditions
with fertilizers supplied as liquid with the irrigation water
rather than as fertilizer units.
Results
[0662] Enhanced heat capacity of the root zone, due to the
fertilizer unit application, was demonstrated to improve plant
survival under low ambient conditions as shown in Table 10.
TABLE-US-00011 TABLE 10 Heat capacity Minimum ambient of
temperature during No. of fertilizer Plant experiment Soil
fertilizer units survival DAP* C..degree. type units**
(Kcal/gC..degree.) rate 1-7; 8-12 4-5 Sand 0 0 27/36- 75% 18-28;
12-17 7-8 Sand 56 1380 31/36- 86% 29-36; 45-55; 56-63 9-10 Clay 0 0
19/36- 53% 37-44 11 Clay 83 1380 27/36- 75% *DAP, Day after
planting. **Average value. Fertilizer units contained 25 g of
water.
Example 8
Fertilizer Units as Fertilizer Source for Plants in Volcanic Origin
Soil and Tropical Climate
[0663] A field trial was conducted in Cartago, Costa-Rica
(N9.862039, W83.898665). Local soil is classified as Andisol, a
volcanic origin soil with graded soil particle distribution
(Sand--50%, Silt--20% and Clay--30%), low pH (5.5), low salinity
level (electrical conductivity--0.1 mS/cm), low CEC (13.5 meq/L)
and high organic matter (3.1%). The climate is defined as tropical
with a high annual precipitation rate (400-600 cm per year), high
humidity and steady high temperatures (26-11.degree. C.).
[0664] Celery and Lettuce seedlings, representative leafy crops,
were transplanted on Day 0. The crops were fertilized by fertilizer
units similar to the type described in Example 6 or solid
commercial fertilizer (YaraMila.TM. Hydrocomplex
12:11:18+Mg+Micro).
[0665] Amounts of fertilizer units and solid commercial fertilizer
were calculated so that all plants received equal amounts of
nitrogen: 2.5 and 3 g of N per plant for celery and lettuce,
respectively. Thirty three fertilizer units per meter at 25 cm deep
and 66 fertilizer units per meter at 15 cm deep were applied in the
celery plot. Eighty three fertilizer units per meter at 15 cm deep
were applied in the lettuce plot. Solid fertilizer was applied
after plant transplantation.
[0666] Marketable yield of each crop was evaluated on Day 45. FIG.
48 presents the combined marketable yield of celery and lettuce.
Data is presented as cumulative percentage of yield relative to
control median of each treatment. Plants fertilized with fertilizer
units were significantly larger compared to plants fertilized with
the commercial solid fertilizer.
Example 9
Microbial Examination of Fertilizer Units
[0667] A laboratory analysis of microbial colonies on the surface
and inside fertilizer units was conducted to measure the transport
of microbial communities from the soil to the fertilizer unit
surface and into the internal zone.
[0668] Microbial activity is required in controlling urea
mineralization and enhancing biodegradability of the product.
Fertilizer units were collected from the root zone of the
experiments described in examples 5 and 7. The number of microbial
colonies was measured on the fertilizer unit surface and within the
internal zone after roots penetrated and developed within it. A
control group included new fertilizer units that were not in
contact with soil and plant roots. High concentration of microbial
colonies was found on the surface and within the internal zone for
both soil types and experimental conditions. Surface concentrations
for fertilizer units ranged between 2.2.times.10.sup.4 to
2.9.times.10.sup.5 CFU/cm.sup.2. Internal zone concentrations for
fertilizer units ranged between 3.5.times.10.sup.6 to
1.3.times.10.sup.5 CFU/0.1 g. Internal zone concentrations for new
fertilizer units (control) were below 10 CFU/1 g. The results
suggested unrestricted transport of microbial communities from the
soil towards the fertilizer unit surface and its inner zone.
Materials and Methods
[0669] The outside of the fertilizer units were washed with running
tap water for about one minute and then washed with sterile water.
Each washed sample was placed into a sterile bag containing 100 mL
of sterile water and manually shaken for about 3 minutes. The
rinsing liquid in appropriate dilutions was examined for microbial
count. The fertilizer unit samples were then aseptically cut and
about 0.1 g of inner contents was removed, transferred to a tube
with 10 mL of sterile water and vortexed for extraction of
microorganisms. The extract was diluted and examined for microbial
count. Microbial count was determined using the pour plate method
with tryptic soy broth and incubation at 30-35.degree. C. for two
days. After incubation the number of microbial colonies was
counted.
Discussion
[0670] High rates of inefficient agrochemical use are attributed to
unknown root distribution, spatial variability in soil structure
and texture (i.e. mineral and organic matter content), temporal
variability of soil conditions (i.e. temperature, moisture, pH,
aeration and salinity), temporal changes in plant demands of
fertilizers and agrochemicals (i.e. species, development stage,
root morphology), and climatic fluctuations throughout the growing
season (i.e. rainfall, temperature, humidity, radiation and
wind).
[0671] Soil-less medium, where optimal conditions for efficient
uptake by roots are maintained, is implemented solely in small
scale containers in greenhouses. This practice is not feasible as a
solution for large scale fields.
[0672] An overall goal of the present invention is supplying
fertilizers and other agrochemicals (e.g. nitrogen, phosphorus,
potassium, fungicides, insecticides, etc.) directly to plant roots
at required amounts and timing regardless of soil and crop types
and conditions.
[0673] Availability and uptake of fertilizer from commercial
products are dramatically affected by soil due to the pH and
reactions with various cations. The present invention relates to
universal additives and formulations that are not affected by soil
type or pH, due to the formation of an artificial environment.
[0674] A problem with the additions of small SAP beads (super
absorbent polymer with diameter of 1 cm) is a fast diffusion of the
additives into the soil. In contrast to the SAP beads that are
currently used, the unit for delivery of agrochemicals to the roots
of a plant of the present invention have a bigger size (in some
embodiments, a fully hydrated volume greater than 600 ml), which
prevents this problem. Aspects of the present invention also
prevent properties from changing due to salts entering the soil.
Furthermore, the concepts herein based on the formation of an
artificial environment in the field, in contrast to other
technology that use hydrogels as a solid replacement.
[0675] The an artificial environment formed by the units of the
present invention encourages root growth and development within the
unit, which enhances and promotes efficient nutrient uptake. Thus,
plants fertilized using the units of the present invention can grow
faster and/or produce a greater yield than crops fertilized by
traditional methods. The artificial environment formed by the units
of the present invention mitigates the effects of suboptimal soil
conditions by, for example, providing a root development zone which
minimizes root growth resistance, provides nutrients, maintains
moisture levels, and protects from the effects of low ambient
temperature.
[0676] Aspects of the present invention that are advantageous and
unique over current technologies and practices include but are not
limited to: [0677] Universality--embodiments of the present
invention are not dependant on temporal and spatial variations of
soil, crop and weather. [0678] Simplicity--embodiments of the
present invention relate to a single application using conventional
equipment. [0679] Economy--embodiments of the present invention
save labor and the amount of agrochemical input (fertilizers and
otheragrochemicals, and energy) for the farmer. [0680]
Sustainability--embodiments of the present invention protect the
environment (water bodies and atmosphere) from contamination as a
result of leaching, runoff and volatilization of agrochemicals.
[0681] Yield--embodiments of the present invention enhance plant
growth rates and yield.
[0682] The present invention provides artificial environments that
encourage or promote root growth or development in different soil
types. Root growth and development are a function of moisture,
oxygen, nutrients and mechanical resistance. The data herein showed
that alginate preformed markedly well with respect to root
development. However, additional formulations (semi-synthetic CMC
and fully synthetic-acrylic acid and acrylamide) show root growth
as well. Aspects of the present invention relate to artificial
environments that provide, moisture and nutrients, while being
mechanically resistant and permeable to oxygen. The data herein
described herein demonstrated the ability of the units of the
invention to deliver water and nutrients to plants throughout the
growing season leading to enhanced plant growth. The data described
herein further demonstrated that the units of the invention can be
used to successfully deliver nutrients to plants in variable soil
types and variable climate conditions.
REFERENCE
[0683] Drew M. C., 1997. Oxygen deficiency and root metabolism:
Injury and acclimation under hypoxia and anoxia. ANNUAL REVIEW OF
PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY Volume: 48 Pages:
223-250. [0684] Habarurema and Steiner, 1997. Soil suitability
classification by farmers in southern Rwanda. Geoderma Volume 75,
Issues 1-2, Pages 75-87 [0685] Hopkins H. T., 1950. Growth and
nutrient accumulation as controlled by oxygen supply to plant
roots. Plant Physiology, 25(2): 193-209. [0686] Nicholson S. E. and
Farrar T. J., 1994. The influence of soil type on the relationships
between NDVI, rainfall, and soil moisture in semiarid Botswana. I.
NDVI response to rainfall. Remote Sensing of Environment Volume 50,
Issue 2, Pages 107-120 [0687] Shaviv A., Mikkelsen R. L. 1993.
Controlled-release fertilizers to increase efficiency of nutrient
use and minimize environmental degradation--A review. Fert. Res.
35, 1-12.
* * * * *
References