JPS6127429B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-insoluble polyelectrolyte polymer soil conditioner and a method for modifying a soil matrix. In another aspect, the present invention relates to novel compositions for modifying plant growth. This novel composition comprises a soil matrix and/or an activator or agro-horticultural agent incorporated within or mixed with polyelectrolyte polymer particles rendered insoluble by cross-linking. Various treatments of soil are well known in the art. First, organic polymer additives were mixed with the soil to improve soil structure (arable land). For example, U.S. Pat. No. 762,995 and U.S. Pat. No. 2,625,529 disclose aqueous polyelectrolytes, such as salts of hydrolyzed polyacrylonitonyl, and salts of copolymers and copolymers of maleic anhydride and vinyl esters. Discloses the use of a method to agglomerate fine soil particles to form crumb-like granules. Agglomeration improves the porosity and permeability of soils, especially cohesive soils that tend to form crusts when subjected to wetting and drying cycles. US Pat. No. 2,889,320 discloses the use of non-polyelectrolytes such as N-methylol polyacrylamide to agglomerate fine soil particles. in general,
All of these natural or synthetic organic polymers are substantially water-soluble. Also, insoluble hydrophilic organic polymers have been mixed with soil to improve soil water capacity. Generally, these polymers swell when the soil is irrigated and retains large amounts of water, thus reducing irritation to plants rooted in the soil.
Cross-linked polyethylene oxide, polymeric alkylene ethers,
The use of various crosslinked insoluble polymers such as chemically modified starches or partially hydrolyzed crosslinked polyacrylamide is disclosed in U.S. Pat.
Disclosed in No. 3336129 and No. 3900378. Other known insoluble polymers that increase soil water capacity include phosphorylated polyvinyl acetate as well as Al, Fe to form metal ion-polymer complexes.
and acid-soluble acrylonitrile polymers treated with metal ions such as alkaline earth metals. It has now been discovered that water-insoluble polyelectrolyte polymers in particulate form can be used to increase both the water and air holding capacity of culture compositions. Furthermore, it has been discovered that the water-insoluble polyelectrolyte polymer particles of the present invention are stable in this type of composition. It is therefore an object of the present invention to provide an improved soil conditioner for increasing the air holding capacity and water capacity of a soil matrix, comprising a polyelectrolyte polymer that has been cross-linked to render it water-insoluble. It is to be. Other purposes are to aid seed germination, to contribute to the growth of young plants and saplings that are less susceptible to moisture sting during use, to have increased air-holding capacity and water capacity, and to improve aeration and soil Increases dissolution capacity, aids plant growth under water-deficit conditions, effectively utilizes natural plant nutrients already present in the composition, allows effective use of fertilizers added to the composition, and improves transplantation. reduce the loss of young trees
Another object of the present invention is to provide an improved culture composition that enables effective use of plant protection agents such as plant growth modifiers, fungicides, insecticides, and nematicides. It is another object of the present invention to provide an improved method containing an active plant growth altering agent and allowing for more effective use of the active plant growth altering agent in subsurface applications as well as in soil and root applications. An object of the present invention is to provide a cultivated body composition. Yet another object is to provide a method for promoting plant survival and growth by contacting the plants with the soil conditioner of the present invention containing as an optional ingredient an active plant growth modifier. Another object of the present invention is to provide a soil matrix amendment having the ability to reversibly and repeatedly absorb water and/or a controlled amount of solution and release them gradually into the soil. be. Another object of the present invention is to provide a novel coated soil conditioner that facilitates mixing with a soil matrix containing a small to large amount of water. . The soil matrix improver of the present invention consists of a water-insoluble polymer electrolyte polymer in granular form. This polyelectrolyte polymer is capable of repeatedly and reversibly absorbing and desorbing aqueous media. When an aqueous medium is retained by the polyelectrolyte polymer of the present invention, the polymer is called a hydrogel. Therefore,
The polyelectrolyte polymer of the present invention can vary between an imbibed state and a dehydrated state, and the polymer can be said to be defined as a hydrogel in its imbibed state. The polyelectrolyte polymer particles of the present invention are characterized by having a specific particle size distribution in their dehydrated state. Furthermore, they are characterized by having a certain water capacity in standard fertilizer solutions and solutions containing about 500 ppm calcium ions and by having a certain gel strength in their hydrogel state. In another embodiment, the soil matrix conditioner of the present invention consists of water-insoluble polyelectrolyte polymer particles as described above mixed with up to 5% by weight of a hydrophobic substance in very fine powder form. . The plant cultivation composition of the present invention contains up to about 21 b particulate insoluble crosslinked polyelectrolyte polymer (32 g/) as mixed with 1 cubic foot of soil. In another embodiment of the invention, the plant culture composition comprises up to about 21 b particulate insoluble polyelectrolyte particles coated with up to about 5% by weight particulate hydrophobic material mixed with each cubic foot of soil. Consists of a combination (32g/). Furthermore, the plant cultivation composition of the present invention separately contains water, fertilizer, an active agent such as a fungicide, a nematocide and/or an insecticide, a soil conditioning agent such as sawdust, and a polymer for soil aggregation. It may contain synthetic soil conditioners such as electrolytes as well as other substances as discussed below. Insoluble polyelectrolyte polymer particles or about 5% by weight
In the soil conditioner of the present invention comprising polymer particles of this kind coated with hydrophobic substances, an active agent can be incorporated into the polymer. Furthermore, the soil conditioner may separately contain or be mixed with known diluents, wetting agents and surfactants. Furthermore, this soil conditioner can be used as a cultivation medium without adding soil, particularly as a growth medium for rooting cut flowers of plants and germination of seeds. A more detailed understanding of the invention may be obtained with reference to the accompanying drawings and the description below. As mentioned above, the novel soil matrix modifier and/or composition of the present invention comprises an insoluble polyelectrolyte polymer. The term "polyelectrolyte" as used herein means a polymer having ionic groups in the chain or as pendant groups. The term "hydrogel" as used herein means an insoluble organic compound that can absorb an aqueous fluid and hold it under moderate pressure. As aforementioned,
Insoluble polyelectrolyte polymers are defined as hydrogels when they have absorbed an aqueous medium. The term "insolubility" or "insolubilization" as used herein is used to refer to the production of a material that is at least about 80% essentially insoluble in an aqueous medium. These polyelectrolyte polymers swell in water and can absorb many times their weight in water.
Insolubilization can be accomplished by a wide variety of methods, including but not limited to ionizing and non-ionizing radiation, covalent, ionic and other bond crosslinking. The term "standard fertilizer solution" as used throughout this specification refers to 200 ppm (N) 20-20-20N,
Means P ₂ O ₅ , K ₂ O solution. In fact, a large number of polyelectrolyte polymers can be used to modify the soil matrix and/or to prepare the novel compositions of the present invention. An important requirement for the particular polyelectrolyte polymer selected is that it contains a relatively large amount of aqueous liquid, preferably
Distilled water weighs more than 100 times its weight, a standard fertilizer solution weighs more than 75 times its weight, and a solution containing 500 ppm calcium ions weighs more than 15 times its weight. The solution is to be able to absorb the solution. This includes organic polymeric compounds such as polymers crosslinked by covalent, ionic, van der Waals forces or hydrogen bonds. Examples of polyelectrolyte polymers that can be used to modify the soil matrix and/or to prepare the novel compositions of the present invention include, among others, the following polymers containing anionic groups: Includes salts of copolymers of acrylic acid or methacrylic acid and acrylamide, and derivatives thereof. Potassium and/or ammonium are preferred as the cation component of the bound anion. The pH of the polyelectrolyte polymers of the present invention is between about 6 and about 9. It should be noted that the present invention is not limited to the use of only one of the polyelectrolyte polymers described above, but encompasses mixtures of two or more polyelectrolyte polymers. Furthermore, it is also possible to use salts of co-crosslinked copolymers of the aforementioned polyelectrolyte polymers or compounds similar thereto. For example, salts of copolymers of acrylic acid and acrylamide and small or large amounts of salts of other copolymers can also be used. As mentioned above, polymers are in particulate form, so the term "polymer particle" as used herein means a single particle or an agglomerate of several particles. As mentioned above, insoluble polyelectrolyte polymers can be made by a number of methods including chemical crosslinking and ion irradiation induced crosslinking. The specific methods for rendering various polyelectrolyte polymers insoluble and possessing the essential features of the present invention do not in themselves imply that certain polyelectrolyte polymers can be practiced in the present invention. It cannot be used as a basis for judgment. That is, any insoluble polyelectrolyte polymer having the necessary requirements can be used in the present invention, regardless of the manner in which it is manufactured. Suitable methods are well known and readily understood by those skilled in the art. A known method is to subject a water-soluble polyelectrolyte to sufficient ionizing radiation to crosslink and render it insolubilized to form a water-insoluble hydrophobic polyelectrolyte. The term "ionizing radiation" as used herein refers to radiation having sufficient energy to cause electronic excitation and/or ionization in polymer molecules and solvent molecules (if a solvent is used). Includes radiation that does not have sufficient energy to affect the nuclei of its constituent atoms. Convenient and preferred sources of ionizing radiation include gamma-emitting radioisotopes such as Co ⁶⁰ and Cs ¹³⁷ , spent nuclear fuel elements, and X-rays such as those produced from conventional X-ray equipment.
Electrons generated by means such as electron beams, Van de Graff accelerators, linear electron accelerators, resonant converters, etc. Ionizing radiation suitable for use in the present invention generally ranges from about 0.05 MEV to about 20 MEV.
It has energy levels in the range of . Irradiation of non-crosslinked polyelectrolytes can be carried out in solid phase or in solution. Solid polymer electrolytes can be irradiated in air, vacuum, or various gas atmospheres, but irradiation in solutions can be applied to water, high dielectric constant organic solvents, or mixtures of water and water-miscible organic solvents. It can be carried out on a water-soluble polymer electrolyte dissolved in Any conventional method for contacting the polyelectrolyte solution with ionizing radiation can be used. The methods described above and other methods for producing crosslinked insoluble polyelectrolyte polymers known to those skilled in the art can be used to produce the polymers of the present invention.
However, some changes in reactant ratios, saponification conditions, reaction parameters, radiation doses, etc. may be necessary to produce compounds with appropriate physicochemical properties. For example, adjustment of crosslink density can be used to produce compounds with gel strengths greater than 0.3 psi. Also, the ratio of ionic to nonionic groups can be adjusted to produce compounds with adequate water uptake capacity and desired stability towards polyvalent cations such as calcium. The term "soil matrix" as used herein refers to any medium in which plants can grow and which provides support, oxygen, water and nutrients and which may include the following media or mixtures thereof: (1) a natural culture consisting of crushed and decomposed rocks and minerals mixed with organic matter in all stages of decay and other ingredients added as fertilizer; (2) glass beads, expanded polystyrene or expanded polyurethane; There are non-natural cultivars such as foamed organic materials, foamed inorganic materials, calcined clay particles, finely ground plastics, etc. Examples of natural crops included within the above definition of soil matrix are peat moss, bark, sawdust, vermiculite, perlite, sand and any mixtures thereof. Note that the terms "soil" and soil matrix are used interchangeably in this specification. Physically speaking, the soil matrix consists of two or three distinct phases: one solid phase, two gaseous phases, and three liquid phases consisting of liquid solutions of water, dissolved salts, and dissolved gases.
These phases are defined by a large number of fine inorganic and organic particles packed together to form a semi-rigid sponge body. The voids or pores between the particles form a substantially interconnected network of channels or tunnels through the soil body. The amount of soil pore space, or soil porosity, determines how much soil volume is potentially available to roots, water, and air. While soil porosity determines how much water can potentially be stored within the soil matrix, pore size, pore distribution and pore number are important factors in determining how much water can potentially be stored in a given soil matrix after irrigation and drainage. Determine the amount actually stored in The same factors are also important in determining the rate of water movement through the soil matrix and are also particularly important in ensuring proper aeration in the potting soil. These factors can be effectively regulated by the addition of soil conditioners of the present invention as discussed below. Soil aeration is the exchange of oxygen and carbon dioxide between the soil and the surface atmosphere. This exchange is
It occurs primarily due to unfilled or open soil pores and is essential to maintain oxygen supply for root growth and uptake. Poor soil aeration causes poor root growth, poor water and nutrient uptake, and makes soil susceptible to the action of pathogens. Water is necessary for plants to grow in soil. However, there must still be good drainage to ensure proper soil aeration. In potting soils commonly used in agricultural gardens, these various purposes are met by a mixture of ingredients. For example, peat moss, humus and other similar organic materials often provide high water capacity, but these will produce poor drainage and aeration. Therefore, nodules such as sand, vermiculite, perlite, bark, wood chips, pumice, etc. are commonly added to increase drainage and aeration. However, not all the water in the soil matrix is available to plant roots. Ingredients that readily absorb water, such as peat moss, for example, do not easily release all of the water to the plants. Therefore, what is important is the available water in the soil matrix or the water potential of the soil solution. The water potential corresponds to the thermodynamic free energy of water, ie, the energy per unit mass.
Per unit volume, it has the same pressure dimension. Therefore, it is often referred to as pressure potential or water potential. Pure liquid water by definition has zero potential. Water located higher than the soil matrix has a positive potential. Also, water used by plants has a small negative potential. Since all soil water contains dissolved salts, there is a seepage effect that reduces water potential. Solid soil particles absorb water. This sorbed water is also at a low potential, so the plants must compete with the soil for water. The surface tension of water within the capillary is another effect that reduces water potential. The physical phenomena of osmotic pressure, adsorption, and capillary action each compete with plants in the soil matrix for water. Only water at a small negative potential is available to plant roots. When the soil matrix is saturated with water, the water potential of the soil matrix approaches the zero value of pure water, and plants grow thick. When the soil matrix is almost dry, the residual water has high negative values, ie up to -100 bar. The water potential of the soil solution is approximately −12
Most plants approach their permanent wilting point in the soil matrix when approaching ~-15 bar. What is permanent withering point?
A condition in which plants do not recover overnight in the dark and at 100% relative humidity. When water is available to plants, the soil matrix is less than about 0 and about -12
It has a larger negative potential than Bar.
Approximately half of the water sorbed by high capacity water sorbing components such as peat moss has a negative water potential that is too large to be available to pre-wilt plants. On the other hand, it has been found that the water retained by the soil conditioner of the present invention is highly available to the plants, ie about 95% is available before reaching the permanent withering point. Therefore, addition of the soil conditioner of the present invention to the soil matrix increases the ability of the improved soil matrix to retain water. This increases the amount of effective water in the water potential available to the plant and extends the time the plant can survive without additional irrigation. All soil bodies contain a large amount of pores of various sizes depending on the components that make up the soil matrix. Many of these pores are very small and do not drain after watering. The percentage (volume) of undrainable pores is called the water capacity of the soil matrix ( _Cw ).
Some of the larger pores drain and therefore fill with air. The percentage (volume) of air contained within the drained pores is the air holding capacity (C _a , air
capacity). Ideally, the soil matrix should have at least 65% water capacity, or 0.65 c.c. of soil.
cc water, and at least 25% air holding capacity,
That is, there should be 0.25 cc of air per 1 c.c. of soil. However, it is well known that adding components to the soil matrix that increase water capacity decreases air holding capacity and vice versa. The fundamental physical relationship between soil matrix water content and air holding capacity depends on the pore size distribution. Generally, an increase in average pore size increases air holding capacity and decreases water capacity, and vice versa. It has now been discovered that when the polyelectrolyte polymer soil conditioner of the present invention is added to the soil matrix, the relationship between air holding capacity and water capacity is disrupted. Addition of these modifiers not only increases the water capacity of the culture composition of the present invention, but also increases the air holding capacity. The increase in air holding capacity of the culture composition occurs due to the increase in total pore volume and pore size due to changes in the soil matrix structure caused by the water-swollen hydrogel particles. However, it was found that the water capacity of the composition did not decrease. In fact, water capacity increases due to the readily available water within the swollen hydrogel particles, as discussed below. Referring to FIG. 1, there is shown a soil matrix 10 consisting of a number of soil particles 12, which are randomly aggregated to form a sponge-like object with pores 14 between the particles 12. The pores also create a generally interconnected network of channels that penetrate the soil body. Moreover, what is randomly distributed in the soil matrix 10 is the polymer electrolyte of the present invention, which is in a dehydrated (unexpanded) state in FIG. 1 and in a water-swollen state in FIG. These are polymer particles 20. As discussed above, each polymer particle of the present invention is capable of absorbing large amounts of aqueous liquid. Addition of the granular polyelectrolyte polymer improver of the present invention to the soil matrix increases the water capacity of the soil matrix. This is because each polymer particle absorbs a large amount of water and swells, as illustrated in FIG. The base soil matrix still has the ability to retain large proportions of water that it would normally retain in the absence of polyelectrolyte hydrogel particles. Furthermore, it has been discovered that when the polymer particles swell to form hydrogel particles, the volume of the soil matrix actually increases, likely due to the creation of its own pores. This swollen hydrogel particle is not only stiff enough to support the weight of the soil matrix, thus creating a place for itself, but also due to the irregularities in the shape of the soil particle are spaced further apart from each other to increase the overall open pore volume of the soil matrix. The above phenomenon is illustrated in Figures 1 and 2 by reference to soil particles 12a-12f and polymer particles 20a. In FIG. 1, the initial position of each particle is shown, with particle 20a surrounded by and in contact with soil particles 12a-12f. A pore volume 14a exists between particles 12a-12f. As mentioned above, in FIG.
a is shown in the dehydrated (unswollen) state. However, in FIG. 2, the soil particles 20a are in a water-swollen state (as hydrogel particles) after absorbing an aqueous medium.
It is shown. Swelling particles 20a are soil particles 12
a to 12f at their initial positions (shown in Figure 1)
They are pushed far apart from each other. Although the swollen hydrogel particles 20a are still surrounded by soil particles 12a-12f, particles 12a-1
The open pore volume 14a between 2f was increased. Furthermore, the swollen hydrogel particles 20a are now particles 12b,
It is in contact with 12c, 12d and 12f. The swelling and gel strength influenced the relative positioning of surrounding particles 12a-12f. Therefore, it appears that the increase in air holding capacity (free pore volume) of the culture composition is caused by the formation of voids within the soil matrix due to swelling of the polymer particles. In short, the swollen hydrogel particles appear to act as perlite-like agglomerates, except when they are essentially all water.
The fact that the hydrogel particles are essentially all water evidences an increased water capacity of the culture composition. Significant morphological changes in the soil matrix with the addition of soil matrix amendments of the present invention result in soil amendments or air that increase water capacity but have little or no effect on air holding capacity. It is a feature that distinguishes it from modifiers that increase retention capacity but decrease water capacity. Amendants commonly used to increase the air-holding capacity of soils, such as peat moss, perlite, and vermiculite, generally increase the average pore size of the soil, thus reducing the soil's ability to retain water through capillary forces. I tend to let it happen. Also, amendments commonly used to increase soil water capacity generally do not have the wet stiffness to increase drainage pore space. They often simply fill existing pores within the soil, thus reducing the soil's air holding capacity. However, the soil conditioner of the present invention does not retain water by capillary forces and is rigid even when swollen with water. As a result, they cause a simultaneous and significant increase in the water and air holding capacity of the culture composition. In practice, it has been found that in order to maximize the air holding capacity of the cultivar composition with the soil conditioner of the present invention, it is necessary to adjust the particle size and gel strength within certain limits. It was done. Additionally, the particle size distribution of the polymer before mixing with the soil matrix is such that essentially all particles in the dehydrated state are smaller than about 8 mesh, preferably about 10 mesh, as measured by the American Standard Sieve.
It was recognized that the particles should be smaller than mesh. Additionally, essentially all of the polymer particles of the present invention are larger than about 200 meshes, preferably about 100 meshes.
The particles are larger than a mesh, most preferably larger than about 40 mesh (US Standard Sieve).
The particle size distribution of polymer particles can be determined by conventional methods,
For example, it can be obtained by grinding large particles or agglomerating small particles. The (water-swellable) hydrogel particles of the present invention are approximately
It should have a gel strength greater than 0.3psi. Gel strength is measured by the following method. Attach a 20 mesh stainless steel sieve (American standard sieve type) to cover the mouth of the cylinder. Approximately 100 g of hydrogel particles swollen to equilibrium with excess water are placed in this cylinder. The particle size of the swollen hydrogel should be larger than the sieve pore size. For example, polymer particles having a particle size larger than 80 mesh (U.S. standard sieve), i.e., those that pass through an 80 mesh sieve,
Normally swells to particle sizes greater than 20 mesh.
Therefore, the swollen hydrogel will not pass through the sieve until pressure is applied. The pressure required to extract the hydrogel through the sieve is determined by placing a piston against the sieve and applying various loads to the piston. Pressure is applied until a pressure is reached that continuously extrudes the hydrogel. From knowledge of the applied load and the cross-sectional area of the piston, the pressure at which the hydrogel is continuously extruded through a 20-mesh sieve (US standard sieve system)
1b/in ² can be calculated. This pressure is called gel strength. The benefits of the soil amendments of the present invention are evaluated by comparing the increase in water and air holding capacity of soils mixed with the amendments to control soil samples. Soil matrix water capacity is the percent volume of water that the soil contains when compared to the volume of soil and water in the soil. The air holding capacity of a soil is the total pore volume minus the water-filled pores. The total pore volume is determined from the wet bulk density and particle density of the soil matrix. In evaluating soil matrix improvers, it is important to increase the water and air holding capacity per unit weight of the improver. The total pore volume percentage (%) can be expressed as: T = (1-D _b /D _p )100 where T = total pore volume percentage (%), D _b = bulk density, i.e. dry solid weight divided by soil volume, D _p = particle density, i.e. soil mixture. In addition, the water capacity and air holding capacity can be expressed as follows. C _w = % water volume = water volume (cc) x 100/soil volume (cc) C _a = % air holding capacity = T-C _w The increase in water and air content per unit weight of amendment is as follows: It can be expressed as X _w = (g of water retained by treated soil) - (g of water retained by control soil) / soil conditioner g X _a = (cc of air in treated soil) - (cc of air in control soil) / Soil conditioner g The polyelectrolyte hydrogel of the present invention simultaneously increases both the % air holding capacity and % water volume of the soil matrix. Approximately 20g _more water per gram of improver
An increase of more than about 30 grams of water per gram of modifier is generally obtained, with an increase of more than about 30 grams of water per gram of modifier being preferred, and an increase of more than about 40 grams of water per gram of modifier being most preferred. In addition, X a _is larger than air, which is approximately 15 c.c. per gram of improver.
is generally achieved, approximately 25 c.c. per gram of improver.
A greater increase than air is preferred, and the improver
An increase of about 35 c.c. of air per gram is most preferred. It was found that the crosslinked polyelectrolyte has a very large water capacity. Charged groups on a polymer interact when in solution and the polymer chain tends to expand to release the charges as much as possible. The actual water capacity is controlled by a number of factors, many of which interact. The important factors are (1) chemical composition, (2) charge density (mole fraction of ionic groups or distance between charges) as well as ionic strength and ionic composition of the aqueous solution absorbed by the polymer, and (3) cross-linking. The molecular weight or crosslink density between Polymer structures that are more hydrophilic absorb more water. Furthermore, the higher the charge density, the greater the water capacity in distilled water; however, compositions with higher charge densities are most influenced by ions dissolved in the water. These ions shield the polymer ions from each other. The polymer chains then assume a less strong and less expanded configuration and therefore do not absorb as much water or swell. Other relevant factors are crosslinking with polyvalent ions, ie, the reaction of polyanions with polyvalent cations and the reactions of polycations with polyvalent anions. When crosslinking occurs, the polymer swells and gradually loses its ability to retain water. The degree of crosslinking is a function of the number and proximity of charged groups and the multivalent ion concentration. Based on tests and observations, the polyelectrolyte of the present invention has a nutrient content of about 75 times its weight in a standard fertilizer solution, and
It can be characterized as having an ionic to nonionic group ratio and crosslink density sufficient to absorb about 15 times its weight or more in a solution containing 500 ppm calcium ions. The ratio of ionic to nonionic monomer units in the polymer backbone or polymer chain for the polyelectrolyte polymers of the present invention is up to about 1, preferably up to about 0.5, and most preferably up to about 0.3. It seems that it should be between about 0.4. The problem of multivalent ion crosslinking is particularly acute when polyelectrolyte polymer amendments are mixed into the soil matrix. Soil solutions usually contain excess amounts of cations such as calcium ions and other multivalent ions (especially when the soil is dry). And crosslinking by calcium is virtually irreversible. However, even so, the polyelectrolyte polymer of the present invention has a concentration of 500 ppm.
Approximately 15% of its weight in soil solution containing Ca ⁺⁺
It was found that the water capacity was more than twice as large. Therefore, a polyelectrolyte polymer containing cationic groups has a water capacity of approximately 15 times or more of its weight in a soil solution containing 500 ppm of polyvalent anions, such as anions such as sulfuric acid and carbonic acid. Seem. Still other factors are the molecular weight or crosslink density between crosslinks. The distance between crosslinks in the polyelectrolyte polymer of the present invention is directly related to its water capacity. Large distances give large water capacities. In another embodiment, the soil conditioner of the invention consists of an insoluble polyelectrolyte polymer whose external surface has been modified by treatment with a hydrophobic substance. Polymers so modified are easy to mix with damp or wet soil. The term "hydrophobic" material refers to a material that floats when placed at a water-air interface. Preferably, the hydrophobic substance is in a very finely divided state. The hydrophobic particles are much finer and have a lower density than the polymer particles of the present invention.
It also has a large surface area. For this purpose, a small amount of hydrophobic particles can be used to provide a thin coating on the external surface of the bulk polymer particles. Surface treatment of polyelectrolyte polymer particles involves physically mixing the polymer particles with up to about 5% by weight of hydrophobic microparticles so that the hydrophobic microparticles physically adhere to the external surface of the polymer particles. This can be conveniently done by producing surface-treated polymer particles that have a surface-treated surface. This is theorized to be due to the ultrafine hydrophobic particles covering or adhering to the external surface of the polymer particles due to electrostatic attraction. Other methods of applying hydrophobic microparticles to polymer particles are well known and include methods such as compounding, mechanical mixing, powder coating, spraying, brushing, shoveling, and the like. It has also been found that the surface coating of hydrophobic particles is physically removed or rendered ineffective in the soil. In-situ removal or neutralization of the hydrophobic surface coating occurs after irrigation of the soil mixture. This is consistent with the theory of electrostatic attraction between polymer particles and hydrophobic microparticles. This is because the presence of polyvalent cations or anions tends to block or cut off electrostatic attraction. Therefore,
It appears that if thoroughly mixed with soil, the electrostatic attraction between polymer particles and hydrophobic particles tends to be broken by the presence of multivalent ions in the soil. Therefore, once the surface coating is removed, the polymer particles can function normally and effectively as hydrophilic substances. It is usually difficult to mix uncoated polyelectrolyte polymer particles with damp or wet soil. Polyelectrolyte polymers tend to aggregate, making it difficult to distribute them evenly in the soil matrix.
The term "moist or wet soil" means a soil in which the water content is substantially greater than about 5% by volume of the aqueous medium and in which the uncoated polyelectrolyte polymer is It becomes increasingly difficult to mix with soils approaching drainage values (field water capacity).
These problems are substantially eliminated by using the surface-coated polymer particles of the present invention. Suitable hydrophobic microparticles include talc, wood flour, hydrophobic silica particles, such as U.S. Pat. No. 3,661,810 and
No. 3,710,510, and strongly hydrophobic metal oxides such as those described in US Pat. No. 3,710,510. Particularly preferred are hydrophobic finely divided silicas having an average equivalent spherical diameter of about 100 mμ or less, a surface area of about 50 m ² /g or more, and no external hydroxyl groups. Activators that can be incorporated into the soil amendments of the present invention are generally known in the art. The term "active agent" as used herein is an agent that directly or indirectly alters the growth of a plant when in contact with or in close proximity to the plant;
Defined to mean an organic, inorganic, organometallic or metal-organic substance that modifies, accelerates or retards. Active agents that can be incorporated into the plant composition of the present invention include: water; fertilizers containing all elements and combinations of elements in organic or inorganic form, solid, liquid or gaseous, essential for plant growth; Algaecides containing quaternary ammonium salts, technical abiethylamine acetate and copper sulfate; Bactericides containing quaternary ammonium salts, antibiotics and N-chlorsuccinimide; Flowering thinners containing phenols; Phosphotrithioates, phthalates, phosphorus Defoliants including lotrichioites and chlorates; fumigants including dithiocarbonates, cyanides, dichloroethyl ethers and halogenated ethane; lime, sulfur, antibiotics, mono- and dithiocarbamates, thiodiazines, sulfonamides, phthalimides, petroleum ethers , naphthoquinone, benzoquinone, disulfide, thiocarbamate, mercuric compound,
Fungicides including tetrahydrophthalimide, arsenate, cupric salts, guanidine salts, triazines, glyoxalidine salts, quinolinium salts and phenylcrotonate; quaternary ammonium salts, phenolic compounds, quaternary pyridinium salts, peracids and formaldehyde Fungicides containing; sulfamates, thorazines, borates, alpha-haloacetamides, carbamates, substituted phenoxy acids, substituted phenoxy alcohols, halogenated fatty acids and salts, substituted phenols, arsonates, substituted ureas, phthalates, dithiocarbamates, thiocarbamates, disulfide, cyanate, chlorate, xanthate,
Substituted benzoic acid, N-1-naphthylphthalamic acid,
Herbicides containing allyl alcohol, aminotriazole, hexachloroacetone, maleic hydrazide and phenylmercuric acetate; natural products (e.g. pyrethrins), arsenic compounds and arsenite, fluosilicates and aluminates, benzoates,
Chlorinated hydrocarbons, phosphates, creato oils and cresylic acids, phosphorothioates, thiophosphates, phosphonates, phosphoro mono- and di-thioates, xanthones, thiocyanodiethyl ether, fluorophosphines, pyrrolidine, phosphorous anhydride, thiazines , carbamates, chlorinates, terpenes, tartrate, thallous sulfate and anabasis; sulfonates;
Acaricides, including sulfites, azobenzines, diimides, benzylates, sulfides, phosphorodithioates, substituted phenols and salts, chlorophenol ethanol, phosphonates, oxalates, sulfones, chlorphenoxymethane, selenates and strychnine, halogenated propane and Nematicides containing propene, dithiocarbamates, phosphorothioates and methyl bromides; insect repellents containing polypropylene glycose, succinates, phthalates, furfural, asafuetida, ethylhexanediol and butyl mesityl oxide; 2-chloro-4-dimethylamino -6-methylpyrimidine, fluoride, coumarin, phosphorus,
Includes insecticides including reddosquil, arsenite and indandione; compatibilizers including carboxyimides, piperonyl radicals and sulfoxides. The novel soil amendments can, if desired, contain, in addition to the above-mentioned active agents, one or more substances that may or may not directly or indirectly influence plant growth. The liquid substance is water, hydrocarbon oil, organic alcohol,
Includes ketones and chlorinated hydrocarbons. Solid substances include pentonite, pumice, china clay, attapulgiaite, talc, quartzite, quartz, diatomaceous earth, fuller's earth, graphite, phosphate, sulfur, pickled pentonite, precipitated calcium carbonate, precipitated calcium phosphate, colloidal silica, sand, vermiculite,
It can contain perlite, pulverized plant material such as corn cob. If desired, the soil conditioner may also contain wetting agents such as anionic wetting agents, nonionic wetting agents, cationic wetting agents, such as alkylaryl sulfonates, polyethylene glycol derivatives, conventional soaps, amino soaps, sulfonate wetting agents, etc. Contains processed animal oils, vegetable and mineral oils, quaternary salts of high molecular weight acids, rosin soaps, sulfates of high molecular weight organic compounds, ethylene oxide condensates of fatty acids, alkylphenols and mercaptans. The plant cultivation composition consists of soil and the granular crosslinked polyelectrolyte polymer of the present invention. The polyelectrolyte hydrogel or polymer can be applied to the surface of the soil or incorporated into the soil to create a mixture of soil and crosslinked polyelectrolyte hydrogel or polymer, respectively. Many variations of the basic composition are possible. For example, the plant composition may consist of a mixture of soil and the dry particulate crosslinked polyelectrolyte polymer itself. Polyelectrolyte polymers sorb water during rainfall or irrigation. Sorption of water by polyelectrolyte polymers prevents excessive loss of water. Naturally occurring nutrients in soil are solubilized by soil water and also sorbed by polyelectrolyte polymers. Here the polyelectrolyte hydrogel acts as a reservoir of natural nutrients. This minimizes leaching of natural nutrients from the soil. Another benefit of adding the dry polyelectrolyte polymer itself to the soil is that it reduces soil compaction, thereby increasing the infiltration of moisture and oxygen into the subsurface growth area. Furthermore, as mentioned above, a major advantage of adding polyelectrolyte polymers to soil is to simultaneously increase the water and air holding capacity of the improved soil matrix. The polyelectrolyte polymers of the present invention are particularly useful for improving soil used in containers. It is well known in the art that container soils present unique problems due to the relatively short soil columns posed by the container shape. After watering, the soil in the container tends to remain well saturated with water and therefore in a state of air starvation. This phenomenon is caused by a stagnant water layer (perched water layer).
table). A common way to alleviate this problem is to use large amounts of nodules such as perlite, vermiculite, pumice, finely ground plastic scrap, and bark in the soil matrix. This nodule can improve air holding capacity if used in sufficient quantities, but generally this is done at the expense of water capacity. That is, as the air holding capacity increases, the water capacity decreases.
Therefore, the ability of polyelectrolyte polymers to increase both the air holding capacity and water capacity of the soil matrix is
Particularly useful in container soils. Water may be incorporated into the polyelectrolyte polymer prior to mixing with the soil. As mentioned above, each individual adsorbent polyelectrolyte particle retains its particulate sacrificiality as it absorbs and sorbs many times its weight in water and swells. The resulting water-swollen particles (defined herein as hydrogels) have water substantially immobilized therein. The water absorbed within this hydrogel is available to the plant roots and is reversibly released by the hydrogel to the plant or soil. When the absorbed water is released, the hydrogel dehydrates and returns to substantially its original size and polymeric state. According to the present invention, seed germination, early growth of seedlings or seedlings and growth of transplants can be effectively improved by contacting the water-swollen hydrogel of the present invention in soil. Hydrogels may be applied to the soil before or after planting seeds, seedlings or transplants. In these applications, water is supplied from the polyelectrolyte hydrogel reservoir and efficiently used by the plant when needed. Thus, this hydrogel is a reservoir of water. There is no excessive water loss due to downward permeability, as is the case with some sandy soils. Fertilizers or other active agents can also be incorporated into the polyelectrolyte hydrogel using water and/or organic solvents before adding the hydrogel material to the soil.
In this case, the polyelectrolyte hydrogel acts as a reservoir and carrier for water, fertilizer, or other active agents, preventing excessive loss of water, fertilizer, and other active agents due to leaching. Fertilizers or other activators are first added to water and/or
Dissolved in organic solutions, insoluble polyelectrolyte polymers are then combined with these solutions. However,
The solution containing the activator becomes incorporated into the polyelectrolyte polymer as it swells into the hydrogel state. The water or organic solvent is then removed from the polyelectrolyte hydrogel to produce a substantially dry polyelectrolyte polymer containing only the active agent before applying the polymer to the soil. The active agent-containing polymer or growth modifier is added to the soil to produce the plant composition of the present invention. When water is applied to this soil, the polymers sorb water. The active agent contained in and on the polymer is solubilized within the polymer. The liquid-swollen hydrogel then acts as a reservoir and carrier for readily available water and active agents to alter plant growth. The active agent is not leached from the soil as rapidly by heavy rainfall or during other accidental or prolonged water applications.
This aspect of the invention has great utility as a means of adding herbicide at the same time as seeding without excessive loss of herbicide through leaching. The polymer is mixed with or covered with soil under dry or substantially dehydrated conditions with substantially dry active agents such as fertilizers, herbicides, nematicides, and insecticides. When water is added to the soil, the active agent is solubilized and the water and active agent are sorbed by the polyelectrolyte polymer. Excessive loss of water through evaporation or loss to the natural water layer and loss of active agent through leaching are thus reduced. Additionally, activation of the activator can be initiated without additional rainfall, since the activated carrier is able to sorb water from so-called dry soils. A particular and distinct advantage of the plant composition of the present invention lies in the manner in which the plant roots utilize polyelectrolyte hydrogels. Plant roots grow into the polyelectrolyte hydrogel itself and come into contact with water and other active agents incorporated within the hydrogel.
The ability of plant roots to grow into the hydrogel allows for even more effective utilization of water and other active agents because they are in direct contact with the roots. Additionally, plants whose roots grow into the hydrogel and become entangled with the cross-linked hydrogel have a high resistance to water stress over long periods of time, especially when removed from the soil for transplantation. . The term "water stress" is defined herein to mean a situation in which the internal water of a plant transpires or evaporates at a rate greater than the rate at which water enters the plant. The former rate is mainly due to the lack of available water. If plants such as tobacco, lettuce, celery, tomatoes, strawberries, annual and perennial plants, hardy annual plants, trees, ornamental plants, young seedlings, etc. are shipped or transplanted, if they are Destruction of these young trees and seedlings is very low if they are grown in a soil composition of In another embodiment of the invention, the plant is further made water stress tolerant by a method comprising contacting its roots with an aqueous slurry of particulate crosslinked hydrogel useful in the invention before planting it in soil. can be done. The physical properties of this slurry are adjusted so that when pulled up, a sufficient amount of hydrogel adheres to the plant roots. A particularly convenient way to increase the effectiveness of this slurry is to add up to 10% by weight of water-soluble thickeners such as high molecular weight polyethylene oxide, hydroxyethyl cellulose, and the like. The roots can be contacted with the slurry by spraying, dipping or other convenient methods. The following examples are given to illustrate the invention and are not to be construed as limiting the invention. Example 1 Three types of soil conditioners are
The comparison was made using ``column)''. What is a soil column?
Generally refers to a soil sample in a columnar glass container in which soil and water can be observed. 350ml glass Buchner funnel (height 18cm, diameter 9.5cm, height 7cm above the 0.5cm fritted glass filter)
was used. Several 0.5 cm holes were drilled in each filter to mimic normal drainage from the pot. The specific gravity of each soil mixture was determined by a standard method, pycnometer according to the method of the National Institutes of Health (1954). Each soil mixture was dried at 110°C for 16 hours and weighed. Each amendment was added to the soil in each column and mixed on each base. The soil in the control column was mixed in a large plastic bag in the same manner. After filling, each sample was pounded in the same gentle manner to avoid unnatural compaction of the soil sample. After gentle pounding as described above, the height of each soil column was measured, and the volume was determined by a predetermined height-to-volume calibration. The soil column was watered with 200 ml of water and then allowed to drain, preferably overnight or for at least 4 to 6 hours. After this drainage time, each container was weighed and the weight of water absorbed by the dry soil was calculated as follows: Weight of water = (total weight) - (container tare) - (dry fill weight). Water supply was repeated six times until a constant value was observed. The volume was then measured again. If the soil volume and water weight are determined in this way, the % volume water content is calculated, and since the specific gravity of water is 1, C _w =water weight/soil volume. The air holding capacity (C _a ) is calculated by the above relation C _a =T-C _w , T=(1-D _b /D _p )100. Three columns were tested for each variation in Examples 1-4. The initial volume of soil was 280 c.c. Depending on the soil type, this weighed between 47 and 320 g. Amount of soil conditioner between 1 and 4 g per column (this is equivalent to between 3.6 and 14.4 g/column)
I added it. Water supply is Peter's solution, i.e. 200ppm
(N) with a strong fertilizer solution. Peter's solution was made from a commercial fertilizer, so _- called 20-20-20 fertilizer, containing 20% nitrogen, 20% _P2O5 and 20% _K2O . In Example 1, a Cornell-type potting soil consisting of half peat moss and half vermiculite was used. The four soil conditioners compared are (1)
Viterra Hydrogel Soil Conditioner (Viterra is a 50% polyethylene oxide and
(2) General Mills product SPG-502S;
(3) An illustrative polymer electrolyte hydrogel soil conditioner of the present invention, a crosslinked polymer of potassium acrylate and acrylamide. First, appropriate amounts of acrylic acid, acrylamide and water are mixed, followed by a neutralization step using 50% by weight potassium hydroxide to create a solution containing 19% by weight potassium acrylate and 35% by weight acrylamide. Ivy. The ratio of monomer units used, ie, potassium acrylate/acrylamide, was 0.348. This solution was then cast onto a paper backing material and
It was conveyor fed under a 1.5 MeV Van de Graaf accelerator operated with a μamp beam stream. The conveyor was placed so that the approach distance to the sample was 5 ft directly below the output window of the accelerator. At a conveyor speed of 8 ft/min, the total dose received by the sample is on the order of 1 megarad. The resulting gel was then dried, ground and classified according to the desired size of the particles by conventional techniques. The experiment was conducted for 3 days in each of the 3 pots, with 6 waterings, 2 waterings per pot. X
The values of _w and X _a represent the increase in the respective water and air content per g of additive, and water is in g
In numbers, air is expressed in units of ^cm3 . The sample results are summarized in the table below.

【table】

[Table] These data indicate that although other polymeric materials were able to increase soil water capacity, only the cross-linked copolymerization of the polyelectrolyte polymer of the present invention, potassium acrylate and acrylamide, increased the air holding capacity. This shows that both the water capacity and water capacity can be significantly increased. This is in contrast to hydrolyzed polyacrylonitonyl graft copolymers of starch materials which actually reduced air holding capacity. Example 2 This example illustrates the effect on standard physical properties of the same three soil amendments as in Example 1 with a commercially available potting soil, humus-enriched field soil. Example 1
The same experimental method as described was used. The results are summarized in the table below.

[Table] Similarly, only the soil conditioner of the present invention, exemplified by the crosslinked copolymer of potassium acrylate and acrylamide, significantly increased both air holding capacity and water capacity. Example 3 This example illustrates the effect of adding certain soil additives to soil/peat moss/perlite 1-1-1 (by volume) type potting soil compared to the soil conditioner of the present invention. The same experimental procedure used in Example 1 was used. The results are summarized in the table below.

【table】

[Table] These data show that even in this 1-1-1 type soil, only the insoluble polyelectrolyte polymer of the present invention (crosslinked copolymer of potassium acrylate and acrylamide) has a large air retention capacity and capacity. This shows that it has a truly remarkable effect on both the amount of water. Example 4 In this example, a soil conditioner was ground and finely ground to pass through two particle size fractions, one from -10 mesh to +40 mesh (US standard sieve) and the other through a 40 mesh sieve. ). In the latter case there was a significant amount of material smaller than 100 meshes in size. Viterra hydrogel soil conditioner and copolymer of potassium acrylate and acrylamide were studied in the same manner as in Example 1. The results are summarized in the table below.

[Table] The data summarized in the table shows that for soil type 1-1-1 (soil-peat moss-perlite by volume),
It is shown that more finely divided hydrogel particles have increased water capacity but decreased air holding capacity. This phenomenon was enhanced in the crosslinked copolymer of potassium acrylate and acrylamide.
The finely ground particles gave a significantly higher water capacity and a much lower air holding capacity than the larger size particles.
The microparticles of hydrogel appear to block soil capillaries and control drainage. Thus, capillaries that would normally contain air are kept full and the air holding capacity is often reduced to that of similar control soils even without finely divided additives. Example 5 The “in pot” method was used. "In-pot" soil refers to soil in a commercially available flower pot. The soil conditioner was mixed with the soil mixture in each container and added. The control was mixed to homogeneity in the same manner (shaken in a plastic bag). The soil was settled by gentle pounding in the manner described above for the "soil column method," preliminary calibration of soil height versus soil volume, watering, overnight drainage, weighing, % volume water (per soil volume (cc)) Weight or volume of water (cc)
) was calculated. Drainable total pore voids or % air holding capacity was determined as follows. The drainage holes in the pots were covered, and the pots were tilted to one side and watered at the bottom to allow air to escape, carefully flooding the pots to the top of the soil surface. Alternatively, the entire pot was placed in a container of water or fertilizer solution to a depth that filled the pot to soil level. In both cases, the pots were watered overnight (16 hours) to eliminate all air. After it was full, I weighed it. Reweighed after draining. Since the specific gravity of water is 1, the difference in weight is the amount of drainage pores at zero suction.
Therefore, the air holding capacity C _a is drainable pore space (cc)/soil volume (cc). Some adjustments were made for very high capacity hydrogels. Rather than using the drained weight after overnight watering to subtract from the fully saturated weight, the equilibrium weight after normal watering was used. This was done because these high capacity gels sometimes absorb a lot of water during overnight irrigation, leading to spurious results. X _a and X _w values were calculated as described above. That is, for water, the weight difference between the amended soil and control soil per unit weight of amendment, and for air, the air volume difference per unit weight of amendment. In this example, a crosslinked copolymer of potassium acrylate and acrylamide (having a ratio of potassium acrylate monomer units to acrylamide units of 0.387 and having about 1 ionic group for every 3 neutral groups) is used. ) was tested at two particle sizes under environmental conditions in a flowerpot. The soil was a 2-2-1 mixture of 2 parts superficial, 2 parts peat moss, and 1 part perlite. Each pot has a diameter of 16.5cm and weighs 600g (1200c.c.)
soil was added. Crosslinked potassium acrylate-acrylamide copolymer was added at 3g per pot (2.5g/). Each pot was watered 7 times with tap water in an amount of 500 ml and allowed to drain equilibrated at intervals. Each data point below represents the average of two pots. The results are summarized in the table below.

[Table] These data show that although the granular crosslinked copolymer of the present invention is slightly less effective in increasing the water capacity of this reinforced organic soil, it is more effective than the fine powder in increasing the air holding capacity. It has been shown to be extremely effective. Example 6 This example uses the "in-pot method" of Example 5 and illustrates the stability to continuous watering in highly ionic polyelectrolyte polymers. This polyelectrolyte hydrogel contained approximately 3 ionic groups to 1 nonionic group. Watering was first with tap water and then with fertilizer solution. This crosslinked copolymer of potassium acrylate and acrylamide had a potassium acrylate to acrylamide monomer unit ratio of 2.82. A mixture of soil, peat moss and perlite from 2-2-1 was used in a 16.5 cm diameter pot. 5g
(4.2 g/) of polyelectrolyte polymer was added to 600 g of soil (which had a volume of approximately 1200 c.c.).
First, water was supplied with tap water four times, and then soil measurements were performed. Then 200ppm(N) Peter's solution approx.
It was watered 6 times with _a fertilizer solution of 1.32 g/, i.e. 20-20-20N, _P2O5 , _K2O %. The results are summarized in Table 6 below.

Table These data in the table show that certain polyelectrolytes lose significant water capacity after reacting with common fertilizer solutions. And the X _w value is
Note the drop from 87 g H ₂ O/g polymer to 22 g H ₂ O/g polymer. Example 7 The "Hachiuchi method" of Example 5 was used. In this example the soil is
1-1-1 was a commercially available greenhouse mixture consisting of a mixture of soil, peat moss, and sand. 0g, 4.5g (3.5g/) or 7.5g in a 16.5cm diameter pot
Contains (6.3g/) of polyelectrolyte polymer
Filled with 735g of soil (1200c.c.). An appropriate amount of polyelectrolyte soil conditioner was pre-mixed with the soil. The polyelectrolyte polymer was a crosslinked copolymer of potassium acrylate and acrylamide with a potassium acrylate to acrylamide monomer ratio of 0.348. This monomer ratio is equivalent to about 1 ionic group to 3 nonionic groups. The water supply method was three times with 500ml of tap water, then Peter's solution (20-20-2N at 200ppm (N),
Water was supplied twice with 500 ml of P ₂ O ₅ , K ₂ O solution). Each water application was followed by at least 6 hours of free drainage. Each of the data points below represents the average of three pots. The measurements were taken after applying the fertilizer solution. The results are summarized in the table below.

TABLE The data in the table show that the addition of the polyelectrolyte polymers of the present invention significantly increases both the water and air holding capacity of highly organic soils at all amendment levels. Comparison with Example 6 also shows that this polyelectrolyte (after watering with fertilizer solution) has a much higher (more than 2 times) water capacity (X _w ). Example 8 The "Hachiuchi method" of Example 5 was used. In this example, the soil consisted of 2 parts peat moss, 1 part vermiculite, and 1 part perlite and a soluble fertilizer. 210g of soil mixture to 0g, 4.5g (3.8g/) or
It was thoroughly mixed with 7.5 g (6.3 g/) of polyelectrolyte polymer and placed in a 16.5 cm diameter pot. The polyelectrolyte polymer was a crosslinked copolymer of potassium acrylate and acrylamide with a potassium acrylate/acrylamide monomer ratio of 0.348. This is a representative modifier of the present invention. Water supply method is 500ml
Water was supplied six times with tap water. Each data point represents the average of five pots. The results are summarized in the table below.

[Table] The data in the table shows that for this nodule-rich soil, the representative insoluble polyelectrolyte polymer of the present invention increased both air holding capacity and water capacity to high levels. There is. Furthermore, the amount of added polymer was not critical as either amount of amendment produced a soil with excellent properties. Note that the grams of water per pot increased as the amount of amendment increased. Example 9 The "Hachiuchi method" of Example 5 was used. This is a comparative example that illustrates the limitations of the invention. This illustrates the inability of certain polymeric soil conditioners to increase both air holding capacity and water capacity under the environmental conditions of the pot. The soil conditioners were Viterra Hydrogel Soil Conditioner (a trade name for a 50% polyethylene oxide - 50% insoluble component soil conditioner manufactured by Union Carbide), and Gelgard XD1300 (a cross-linked partially hydrolyzed polyacrylamide (approximately 40
% hydrolysis, particles smaller than 100 mesh (US standard sieve)). 2-2-1, 506g, approximately 1200c.c. in a 16.5cm diameter pot
Soil mixture (2 parts topsoil, 2 parts peat moss,
1 part perlite enriched organic soil). Add 15g/pot (12.5g/) of Viterra Hydrogel Soil Conditioner to 8 pots;
3.5g (2.9g/) of modified polyacrylamide
Added to separate pots. Each data point below represents the average of 8 pots. Each pot was watered with 500 ml of tap water seven times, and allowed to drain at regular intervals. The C _a value was calculated by the ``column method'' rather than the ``pot method.'' The results are summarized in the table below.

TABLE The data in the table illustrate that certain soil amendments can greatly increase the water capacity of a soil, but do not necessarily increase the air holding capacity or even decrease it. Example 10 The “Hachiuchi method” of Example 5 was used. Five types of soil conditioners were compared. namely, potassium-bonded polyacrylate (manufactured by Toho Rayon Co., potassium content 30-35% of the weight of the polymer); a product of General Mills Co.
SPG-5025, a hydrolyzed polyacrylonitonyl graft copolymer of starch; Grain Processing Co. product 35-A100, prepared by saponifying a starch-acrylonitonyl graft copolymer with an aqueous alcohol solution. Granular water-insoluble alkali metal carboxylate salt of starch-acrylonitonyl graft copolymer (described in U.S. Pat. No. 3,661,815); Gelgard XD-1300 product, crosslinked partially hydrolyzed polyacrylamide (approximately 40% hydrolyzed;
100 mesh); and the polyelectrolyte polymer of the present invention. The polyelectrolyte polymer was a crosslinked copolymer of potassium acrylate and acrylamide with a potassium acrylate to acrylamide monomer ratio of 0.348. Standard Cornell recommended ingredients including lime (Cornell
Recommendations for Commercial Floriculture
A 2-1-1 mixture (peat moss, vermiculite, perlite) was used, to which was added fertilizer (see Crops. April 1974 issue, p. 3, Cornell University Press). 130g (1200c.c.) of soil mixture to 5g (4.2g/
) and placed in a 16.5 cm diameter pot. The data points below represent the average of three pots for each treatment. Refilled water 20 times. i.e. 6 times with tap water, Peter's 20-20-20,
200ppm (N) fertilizer solution, 14 times with 500ml each.
Each watering was followed by at least 8 hours of ad libitum watering. All pots were dried to normal levels four times before watering to simulate normal growth conditions. Of course, the salt concentration of the soil solution increases as the soil dries. Immediately before data collection, all pots were watered three times with tap water to leach out accumulated salts. The results are summarized in the table below.

TABLE The data in the table above demonstrate that the only polymers that significantly increase the water and air holding capacity of the compositions are the polymers of the present invention. Example 11 This example compares the equilibrium solution holding capacity (X value) of a number of known polymeric soil amendments and the insoluble polyelectrolyte soil amendment of the present invention. The polymers tested were (1) the polyelectrolyte polymer of the invention described in Example 10; (2) potassium-bonded polyacrylate (manufactured by Toho Rayon Co., Ltd., potassium content 30-35% of the weight of the polymer); ); (3) General Mills products
SPG-5025, a hydrolyzed polyacrylonitonyl graft copolymer of starch; (4) Grain Processing Co. product 35-A100, a starch-acrylonitonyl graft copolymer saponified with an aqueous alcoholic solution of a base; Granular water-insoluble alkali metal carboxylate salts of starch-acrylonitonyl graft copolymers prepared by
3661815); (5) Gelgard XD-1300 product (manufactured by Dow Corning);
It was a trademark of the company (particle size smaller than mesh). Equilibrium capacity (X value) was calculated by the following formula. X value = weight of swollen polymer - weight of dry polymer / weight of dry polymer The test method was as follows. A weighed amount of each dry (dehydrated) polymer was placed in the solution and gently stirred overnight. The water-swollen polymer particles were then separated and weighed. The X value was calculated according to the formula above. An effective soil conditioner must be of suitable chemical composition so that it does not irreversibly crosslink and thereby lose its water capacity in the presence of multivalent ions in the soil solution. Table _XI below shows the equilibrium capacity (X
value). The average concentration in tap water is
Concentrations of 36 ppm Ca ⁺⁺ and 500 ppm Ca ⁺⁺ were used, a concentration commonly found in soil solutions. Ca ⁺⁺ to illustrate the irreversibility of crosslinking by calcium
The swollen polymer in solution was filtered and soaked in excess deionized water overnight and the X value was determined again. The results of these tests are summarized in Table XI below.

TABLE The data in Table XI demonstrate that representative polyelectrolyte polymers of the present invention retain their water capacity and do not irreversibly crosslink in the presence of multivalent ions in soil solutions. Note that the Gelgard product provides significant water capacity in the 500 ppm Ca ⁺⁺ solution, and Examples 9 and 10 illustrate that this reduces the air holding capacity of the soil. Example 12 The “Hachiuchi method” of Example 5 was used. For market ( _Cv )
Cucumbers were grown in soil consisting of 2 parts topsoil, 2 parts peat moss and 1 part perlite. The treated bodies were control soil, control soil and Viterra hydrogel soil conditioner (trademark of 50% polyethylene oxide - 50% inert ingredients soil conditioner manufactured by Union Carbide) or three types of polyelectrolyte polymers of the present invention. It was made of a crosslinked copolymer of potassium acrylate and acrylamide. The crosslinked polyelectrolyte polymers of the present invention used have the same chemical composition, i.e.
It had a potassium acrylate to acrylamide monomer ratio of 0.387. However, each of the three samples had a different degree of crosslinking and therefore had a different water capacity. The amounts used of each of the three species of the invention were varied depending on their equilibrium water content in tap water to obtain approximately the same amount of hydrogel-bound water per pot.
Mix 600g (1200c.c.) of soil with soil conditioner,
I put it in a 16.5cm diameter pot. The amount of each soil conditioner used per pot was 0g for the control example, 15g for the Viterra hydrogel soil conditioner, and the polyelectrolyte polymer sample of the present invention.
They were 4 g of sample A, 3 g of sample B, and 2.5 g of sample C. After obtaining the preliminary data, the water supply method was as follows: 4 times with 500 ml of tap water each, followed by alternating water supply with 200ppm (N) 20-20-20 Peter solution (8 times) and tap water (7 times). The trial was conducted over a total period of about 61 days.
Each data point represents the average of 5 pots. Each pot is 1
I had a real plant. Plant growth data were taken on day 43. The results are summarized in Table XII, Tables and Tables below.

【table】

【table】

【table】

[Table] Improvements in soil properties result from plant growth data. The number of nodes increases by up to 150% compared to the control soil, and the number of leaves extending beyond the nodes with a length of 1.3 cm or more increases by more than 400%. It can therefore be seen that cross-linked copolymers of potassium acrylate and acrylamide aid plant growth in a dramatic manner. Example 13 The “Hachiuchi method” of Example 5 was used. The effects of a cross-linked copolymer of potassium acrylate and acrylamide (with a potassium acrylate to acrylamide monomer unit ratio of 0.348) and Viterra hydrogel soil conditioner on soil properties and growth of red kidney bean (phaseolus vulgris) were determined. . The soil used was a commercially available indoor potting soil mixture (by volume, 45% peat, 40% wood and resin chips, 10% pumice,
and 5% sand and fertilizer). 320g (1200
One plant was planted in each 16.5 cm diameter pot containing cc) soil. Data were taken after four waterings, followed by nine washes with tap water, then two waterings with Peter's 20-20-20 fertilizer solution at 200 (N) ppm. both
It was 500ml each. Viterra hydrogel soil conditioner was added at 10g per pot (8.3g/). The amount of crosslinked copolymer of potassium acrylate and acrylamide was 2 g per pot (1.7 g/). Each data point represents the average of 5 pots. The total growth period is approximately
It was 45 days old. When the plants matured by flowering, the entire pot was watered several times to ensure saturation, and the surface was covered with plastic film to stop evaporative losses and allow the plants to wilt. At the first signs of wilting, moisture was measured in each pot and compared with the soil sample. The results are summarized in the tables and tables below.

【table】

[Table] Cross-linked copolymer of potassium and acrylamide 2g/pot These data demonstrate how the cross-linked copolymer of potassium acrylate and acrylamide increases air holding capacity as well as water capacity during long-term bean growth. It shows how to increase. The crosslinked copolymer of potassium acrylate and acrylamide is
It has been shown to significantly improve soil properties even when added in much lower amounts (1/5) than Viterra hydrogel soil conditioner. These data also demonstrate that the water retained by the polymers of the present invention is highly effective for use by plants. 2g of polyelectrolyte polymer with an extra 100g that the plant would be able to use before wilting
Note that it retains even more water. Example 14 Big Boy (C
_v ) studied the growth of tomato plants. The soil was a 1-1-1 mixture of topsoil, peat moss, and sand by volume. The container was a #44 "Market Bag", a pressed fiber maker approximately 14 x 19.7 x 7 cm in size. 853g in each container
(1200 c.c.) of soil and planted 12 tomato transplants per container. Grew 10 containers (120 plants). That is, 5 were control examples, and 5 containers contained 7.3 g (6.1 g/) of crosslinked copolymer per container. The vessels were watered as needed over a 60 day period and similarly fertilized with 200 ppm (N) Peter's solution (20-20-20). After 60 days, all plants were watered thoroughly and allowed to stand. Control tomato plants wilt in 4 days and treated tomato plants wilt in 7 days.
It wilted within days, thus an improvement of 75%.
After wilting, cut the plant at soil level and 110
dried in an oven for 24 hours at °C and weighed for growth indicators. Control plants (60 plants) averaged 1
The final dry weight was 0.71 g. Tomato plants grown in the treated soil averaged 0.92 g dry weight per plant, thus a 30% improvement. Thus, it can be seen that more mature plants grow in soil treated with cross-linked copolymers and are able to survive longer watering intervals. Example 15 Three chrysanthemum varieties were grown in control soil and in a cross-linked copolymer of potassium acrylate and acrylamide (0.348
was grown in soil amended with potassium acrylate to acrylamide monomer unit ratio of . The soil was 3 parts by volume peat moss, 2 parts each perlite, vermiculite and sand. Three rooted cuttings of one of the following varieties were planted in 20 cm diameter plastic pots each containing 1.445 g of the mixture (2600 c.c.). Granchild, White Granchild or Illini Spinningwheel. There were 18 pots for each variety, thus 162 plants. Half of the pots were a control, and the other half contained 10 g (8.3 g/) of the crosslinked copolymer. These plants are protected by rain or sprinklers.
Watered externally for a week and then transferred to a greenhouse for shelf life testing. The plants were allowed to wilt after one final and thorough watering. The wilting time (withering time) was measured when all the leaves had withered and the flowers began to wither. Of course, withering time is an important parameter for florists. The results for number of wilting days are summarized in the table below.

[Table] Processing
Improvement rate (%) +75 +63 +63
These data demonstrate that treating soils that grow expensive flowers with a cross-linked copolymer of potassium acrylate and acrylamide, which is a representative polyelectrolyte polymer of the present invention, can prolong the wilting time of flowers. This shows that there has been a significant improvement. Example 16 In this example, two poinsettia plant varieties,
Eckespoint C-1 Red
1Red) and Dark Red Annette Hegg were grown in a Gornell-type mixture of peat moss, vermiculite, and perlite, with the addition of 1 part soil per 1 kg of topsoil. The treatments consisted of control soils and soils amended with Viterra hydrogel soil amendment or a cross-linked copolymer of potassium acrylate and acrylamide (having a potassium acrylate to acrylamide monomer unit ratio of 0.348). The purpose of these trials is to grow stock plants for the consumer market, not flower plants. Therefore, the criteria for success were cut flowers (>5 cm long) or total number of branches produced. Twelve pots were used for each treatment of the two varieties. These are approximately 1 per pot.
It was grown in a 16.5 cm diameter pot containing 186 g (1100 c.c.) of soil. Treatment with Viterra Hydrogel Soil Conditioner: 8.8g (8g/) and 13.2g/pot
(12g/). The cross-linked copolymer was studied at a dosage of 4.4 g per pot (4 Kg/m ³ ). Water is supplied as needed, generally at 250ppm (N)
It was carried out using Peter's solution with the composition (25−10−10N−P ₂ O ₅ −K ₂ O). On the 7th day after planting, the top 3-4 cm of the new growth was cut off by hand to induce "breaks", ie, the formation of branches (cut flowers). After 25 days, growth was controlled by spraying the leaves with a growth retardant, Cycocel (salt-cut trimethyl 2-chloroethylammonium manufactured by American Cyanamid) at 3000 ppm. After 45 days, all cut flowers larger than 6 cm, which were classified as valid cut flowers, were removed. Smaller branches were also removed if they were larger than 2 cm. These were called branches. The number of cut flowers and branches was counted. In addition, the total weight of cut flowers and branches was measured to further quantify the beneficial effects of soil amendments. The results are summarized in the tables and tables below.

【table】

Table: Low loadings of Viterra hydrogel soil conditioner did not significantly improve the number of cut flowers or their total weight. High loadings of Viterra hydrogel soil conditioner had significant effects, especially for the Expoint species. The cross-linked copolymer produced significant yield improvements for both poinsettia varieties and at one-third the amount that Viterra hydrogel soil conditioner showed similar improvement. Example 17 Four reagent gardens were used in 40-inch raised beds, two rows per bed, and 10-inch seed spacing. The soil is
It was a high-clay soil component found in the Salinas Valley region of California. The seeding area was made using a hollow digging tool (jibur) to a width of 3/4 inch and a depth of 1/2 inch. One lettuce seed (C _v −
Hartnell) and then subjected to one of the three treatments described below. For the first treatment, i.e. control, approximately 1/2 teaspoon
of vermiculite was placed on top of each of the 50 seeds, and the seeds were pounded to cover each part of each vegetable garden. In the second treatment, vermiculite was added mixed with approximately 0.025 g of dry polymer, also in 50 locations per garden. In the third treatment, approximately 1/2 teaspoon (approximately 2.5 g), which has been sufficiently preswollen with tap water,
of hydrogel (approximately 0.01 g of dry polymer) was placed on top of each seed in 50 locations in each garden. The hydrogel was a fully swollen crosslinked copolymer of potassium acrylate and acrylamide (having a potassium acrylate to acrylamide monomer unit ratio of 0.348). The four gardens were then watered evenly at approximately 1/2 inch. Germination/expression was counted 4 days after planting without rain and the following results were obtained. Control area 0.5% expression Dry polymer treated area 30% expression Hydrogel treated area 49% expression Example 18 Crosslinked copolymer of potassium acrylate and acrylamide (having a potassium acrylate to acrylamide monomer unit ratio of 0.348) and 0.5 Powdered test coatings (dry or wet) at concentrations of ~3% by weight were placed in plastic bags and shaken vigorously to coat the copolymer. The copolymer particles had a particle size between -10 mesh and 60 mesh. In all seven tests, 3.2 g of coated copolymer particles were applied to 200 c.c. of peat moss and humus enriched wetland soil.
and mixed. The six test coatings were as follows. 1)
Superhydrophobic fumed silica particles (trademarked by Tsuruco Co., Ltd., North Billerica, Mass.)
commercially available as Tullonox500). The hydrophobic fumed silica particles had a nominal particle size of 0.007μ, a theoretical surface area of 325 m ² /g, a surface area of 225 m ² /g by nitrogen adsorption measurements, and a bulk density of 31 b/ft ³ . 2) Hydrophobic fumed silica (commercially available from Kabot under the trademark CAB-O-SIL Type M-5). The fumed silica particles have a very small particle size and a large surface area of between 50 and 400 m ² /g. 3) Hydrophobic fumed silica (sold under the trademark Silanox 101 by Kabot Corporation, Boston, Mass.).
4) Wood flour made from Douglas fir (commercially available as grade T-100 from Menashia, Oregon) with a particle size such that 99% of it passes 100 mesh. The polymer particles are made of polyvinyl alcohol.
It was pre-wetted with a wt% solution to make its external surface adhesive to wood flour. 5) Hydrophobic diatomaceous earth filter powder (trademarked by John Manville Products Co., Lapacz, California)
sold as Celite) and 99%
The particle size is such that it can pass 150 meters. 6)
A hydrophobic talcum powder (commercially available as grade 127 from Uittaker-Clark & Daniels, South Plainfield, New Jersey) of a particle size such that 99% passes through the 120 mesh. The effectiveness of each coating in preventing the formation of aggregates due to rapid uptake of soil water was observed in comparison to the uncoated polyelectrolyte polymer of the present invention. Agglomeration will prevent homogeneous mixing of the polymer particles and soil. The results of these tests are summarized in the table below.

[Table] Although various examples described in the present invention were carried out using a crosslinked copolymer of potassium acrylate and acrylamide as a polymer component, the present invention is not limited thereto. The present invention contemplates the use of any of the aforementioned polyelectrolyte polymers as a soil conditioner and as a component in the plant culture compositions of the present invention. The insoluble polyelectrolyte polymers of the present invention are not consumed to a significant extent by the plants themselves, and are not consumed in the plant composition until they absorb soil solution and become a reservoir for the plants. Acts as an active ingredient. They are used for their ability to incorporate or adsorb aqueous or organic solvent solutions of organic or inorganic compounds and/or various solutes into their matrix and to release these adsorbed substances into the surrounding environment, as well as for their ability to Due to its ability to increase the air holding capacity of soil when swollen by. It has widespread utility in the field of agriculture. The aforementioned activators are not chemically affected by or react with the inert polyelectrolyte polymers of the present invention. The polyelectrolyte polymers of the present invention provide an effective and improved means of performing the known functions of water and other known active agents or pesticides.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view showing the improved soil matrix of the present invention containing polyelectrolyte polymer particles in a dehydrated state, and FIG. 2 is an enlarged view showing the polyelectrolyte polymer particles in a water-swollen state. It is an enlarged view showing the improved soil matrix of . 12 (12a, 12b, 12c,
12d, 12e, 12f) are soil particles, 14 (1
4a) is a pore, and 20 (20a) is a polymer particle.

Claims (1)

[Scope of Claims] 1. A soil conditioner suitable for mixing with a soil matrix having a water content of about 5% by volume or less and/or as a cultivated material itself, which is made insoluble by cross-linking and comprising polyelectrolyte polymer particles comprising a salt of a copolymer of (meth)acrylic acid and acrylamide or a derivative thereof having a particle size between about 8 meshes and about 200 meshes, wherein the polymer particles are dissolved in the presence of an aqueous solution. to give a swollen hydrogel with a gel strength greater than about 0.3 psi, and further contains calcium ions at about 100 times its weight in distilled water, about 75 times its weight in standard fertilizer solution, and 500 ppm. A soil conditioner that is further defined as being capable of reversibly absorbing and desorbing approximately 15 times its weight or more in solution. 2. The soil improvement agent according to claim 1, which contains an active agent such as water, fertilizer, or agricultural chemical. 3. The soil conditioner according to claim 1, characterized in that it contains at least one of the following substances; water, hydrocarbon oil, organic alcohol, ketone, chlorinated hydrocarbon, bentonite, pumice, china clay. , attapulgite, talc, pyrofluorite, quartz, diatomaceous earth, fuller's earth, graphite, phosphate, sulfur pickled bentonite, precipitated calcium carbonate, precipitated calcium phosphate, colloidal silica,
Sand, vermiculite, perlite or fine plant debris. 4. The soil conditioner according to claim 1, which contains a wetting agent. 5. The soil conditioner of claim 1, wherein the polymer particles have a particle size of between about 10 mesh and about 100 mesh. 6. The soil conditioner of claim 5, wherein the polymer particles have a particle size of between about 10 mesh and about 40 mesh. 7. A soil conditioner according to claims 1 to 6, characterized in that the polymer electrolyte polymer particles are coated with an ultrafine hydrophobic substance in an amount of up to 5% by weight. 8. The soil conditioner according to claim 7, wherein the hydrophobic substance is composed of hydrophobic silica particles having an average uniform spherical diameter of about 100 mμ or less and a specific surface area of at least 50 m ² /g. .