Granular fertilizer

FIELD OF THE INVENTION

[0002] A fertilizer comprising plant nutrient(s) and soil conditioner(s) to maximize nutrient availability by minimizing leaching, dilution and runoff and a method of producing the same.

BACKGROUND OF THE INVENTION

[0003] The rapid increase in the world's population is the main driving force for the growing demand for agricultural and horticultural products. As this demand has increased, so has the demand for nutrients to support plant growth. By 2050, world population will be approximately 11,000,000,000; and as a result, the need for plant nutrients (fertilizer) will continue to grow.

[0004] Fertilizers are essential in today's agricultural and horticultural systems to replace the elements removed from the soil by some means. Fertilizers are materials containing at least one of the plant nutrients in a form assimilable or “available” to plants in known amounts. Generally, a plant nutrient is taken up by plant roots or foliage in the form of a solution in water. Soil nutrients removed, must be replenished or the soil becomes impoverished of those nutrients, and plant growth decreases. The failure to maintain soil nutrients has led to the downfall of many ancient societies. When nutrients are not replenished to soils, sometimes even the growth of native vegetation cannot be supported and the areas are left environmentally degraded.

[0005] Soils are the loose, unconsolidated materials covering the earth, which are derived from rock materials, either in place or carried by wind or water from another location, and serve to physically support plants and provide water and nutrients for growth. They also contain populations of microorganisms and soil fauna that are integral to soil development, nutrient and water dynamics, weathering of rock materials, and the physical characteristics of soil.

[0006] Collectively, the fertilizers and soils play a significant role in the development and growth of plants since plant nutrient is taken up by plant roots or foliage. All species of plants need practically the same nutrients, but they differ both in the amounts of particular nutrients needed for growth and their ability to use nutrients that are available in the soil. Soil factors such as soil pH, cation exchange in soils, and organic matter in soils influence nutrient availability and are important consideration in fertilizer use.

[0007] The concept of ecology of ecologically sustainable industrial development motivated producers and consumers to use products and operate industry using the best technologies and techniques to minimize adverse environmental impact. In relation to fertilizer, leaching and runoff are two primary areas of concern. Leaching is the process by which a fertilizer is carried downward in the soil. Where the plants' roots reside near soil surface, dilution of the fertilizer within substantial depth of soil may reduce the fertilizer concentration available to the plant. Runoff is the surface movement of the fertilizer across the soil. Eroded soil particles carry adsorbed chemicals with them, especially phosphorous which is adsorbed strongly by most mineral soils. Organic matter, crop debris, applied fertilizer and animal waste can also be physically transported by runoff water. The dissolution of nutrients from all such transported suspended material will continue or perhaps increase in receiving water bodies, sometimes causing serious water quality problems. When runoff extends to a non-target site, serious consequences can result with some fertilizers.

[0008] Traditionally, when fertilizers are added to soil, there is little consideration given to the soils ability to hold the nutrients for uptake by the plants. Rather, there is an “assumed” expectation that the soil will manage the nutrients effectively. In reality, there are soil measures such as soil permeability (as measured and reported by US EPA) that have a dramatic effect on water and fertilizer performance throughout the soil. Ignoring these facts would be similar to ignoring the fact that seeds in general do not germinate and establish well in compacted soil. Just as soil is tilled first to establish most seeds, the soil needs to be conditioned to maximize fertilization results.

[0009] Over-fertilization leads to two serious concerns. The first is simply that of cost. Every dollar spent on fertilization that does not return at least the same amount in increased yield is wasted. Besides wasting money, over-fertilization leads to a second, off-farm concern: pollution of groundwater supplies and downstream ecosystems due to transport of fertilizer nutrients. Discharges of nutrients into surface and subsurface waters can be detrimental to the beneficial uses, aesthetic appeal, flora and fauna of receiving water bodies. When this happens, growers suffer only indirectly; society as a whole bears the brunt of the cost.

[0010] Fertilizer management is by far the most critical practice for controlling nutrient losses and crop production. In essence, the more fertilizer that is applied to a field, the greater is the potential for losses. Therefore, a good fertilizer program is one that applies the minimum amount of fertilizer needed to obtain the most profitable yield. Since only dissolved materials usually move in percolating water, the soluble forms of nitrogen and phosphorous will be most likely to move downwards. The way to control nutrient losses is straightforward: limit the amount of soluble nutrients in the soil-water and reduce the transport capacity of the water. Important practices which reduce nutrient loss are soil conservation, efficient irrigation and fertilization techniques.

[0011] Water soluble polyacrylamides (PAMs) have been proposed as soil amendments for various agricultural purposes. Water soluble polymers, generically described as polyacrylamides (PAMs) appear to have a variety of beneficial soil amendment properties, including minimization of water run-off, erosion, and crusting, stabilization of soil structure, and binding of nutrients and microbes within soil.

[0012] Since the late 1980's there has been renewed interest in the use of water soluble polymers for soil physical improvement. Although PAM has been used for soil structure improvement since the 1940's and in agriculture since the 1950's the kinds of PAM used and the methods of application were different. Early PAMs had lower molecular weights than today's PAMs. They were applied to the soil at high rates, and were incorporated into the top soil by tillage.

[0013] In addition to the current interest in anionic PAMs as soil conditioners, they are widely used for other applications. PAMs are used for mineral and coal processing, petroleum production, paper making, water treating, food processing, and other miscellaneous applications.

[0014] Polyacrylamide is a synthetic water-soluble polymer made from monomers of acrylamide. It binds soil particles in the water and irrigated furrow together, making particles larger so the water has a harder time washing them out of the field.

[0015] Polyacrylamides are compounds that hold on to nutrients and troublesome microbes before they can escape from soil and make their way to ponds, lakes, streams, rivers, and/or ground water. PAM has been shown to help keep nutrients, such as nitrogen and phosphorous in fertilizers, from traveling beyond the farm in irrigation runoff. Similarly, PAM helps keep disease causing microbes, like those in cow, pig, or fish manure, from being swept beyond the confines of farmyards or feedlots.

[0016] It has been well documented that PAM improves soil permeability to improve water penetration to shallow plants. PAM is an anionic or neutral long-chained organic polyacrylamide. Therefore, availability of nutrients applied to the soil surface may be enhanced on permeable soil by the movement of the ions down into the rooting zone (infiltration or penetration). PAM also reduces soil movement during rain events on moderate slopes hence reducing soil and fertilizer runoff. Separation performance can be increased by using PAM. PAM bonds together fine particles and increases capture and removal of Nitrogen and Phosphorous nutrients as found by the USDA. The USDA has demonstrated that the combination of PAM and calcium allows the calcium ions to act as a bridge between anionic soil surfaces and anionic PAM macromolecules when using them for infiltration and erosion control. Soil particles, water within the soil, soil microorganisms, and the soil atmosphere form a complex system in which numerous chemical, physical and biological reactions occur. The fate of nutrients and crop responses to them are influenced by each of the above components in a very complex fashion.

[0017] PAM's three most common forms are dry granules, solid blocks (cubes) and emulsified liquids. The application method of PAM chosen depends on the form of PAM selected.

[0018] The use of dry granular PAM into irrigation water requires the use of an augured metering system and excellent mixing and thorough dissolving before the PAM reaches the irrigated furrows. Dry granules of PAM can be applied either by dissolving directly in the irrigation ditch before it hits the furrow, or applied directly in the furrow using what is known as the “patch method”. The patch method involves placing PAM at the point in the furrow where the water first hits; applying it for a length of about 3-5 feet down the furrow to reduce the risk of the PAM becoming buried in the furrow or washing down the furrow with little to no effect. The patch method creates a sort of gel-slab at the top of the furrow where the water slowly dissolves the PAM and carries it down the furrow.

[0019] In order for the PAM to dissolve into a liquid properly in the irrigation ditch it must have proper agitation. Unlike sugar or salt which dissolve fairly quick in water, granular PAM needs to be agitated thoroughly in order for it to dissolve. If not agitated, PAM globules form, and in time the globules can float down the furrow with little effect on the furrow erosion. A way to make sure the applied PAM is dissolved is to have a drop structure in the ditch to add turbulence to the water before it hits the furrow. Another tip to achieve desired dissolving is to apply it close to the point where the irrigation water first hits the ditch. In a concrete ditch, tins or boards will provide sufficient turbulence. In an earthen ditch a drop dam works nicely.

[0020] There are many known problems for applying PAM to the soil using present applications. The dry formulation is easy to handle, but must be kept dry due to its affinity for moisture. The dry material is primarily used for open ditch application due to the difficulty of getting the material into a water pipeline. For best results, the applicators used to dispense the bulk material are placed upstream of the irrigation set and away from any splashing water droplets.

[0021] When exposed to humidity, polyacrylamide granules tend to stick to each other and to drop tubes which can then plug. The flow rate for granular PAM ranges from 2 to 33 grams per minute depending on irrigation flow and desired concentration in the irrigation water. A small error in the rate of metered PAM will lead to large differences in concentration in irrigation inflow water. Dry PAM applicator considerations include: dispensing rates of 1 to 35 grams/min; precalibrated or easily calibrated for fast setup in the field; portability; lasting power supply.

[0022] With a closed pipe system, the liquid formulation is normally recommended. Using an injector pump, the liquid can be pumped directly into the irrigation pipeline. Turbulence in the pipeline, such as an elbow, helps mix the PAM with the water. The natural turbulence in a pipeline 100 feet long or greater is likely sufficient for mixing. The liquid material is, however, difficult to handle outside of the container. To clean up anything that has come in contact with liquid PAM, it is common practice to “wash” the PAM off with soil. The PAM will adhere to the soil particles making cleanup with water possible.

[0023] The liquid formulation also can be used for open ditch applications; however, if a pump is not being used, and the liquid dribbles into the water, the viscosity of the liquid can change with temperature changing the calibrated delivery rate. Keeping the containers out of direct sunlight will reduce, but not eliminate, this problem.

[0024] Liquid PAM can be metered directly from the container into the irrigation ditch, directly into the furrow, or through a pipe line or injector pump. Emulsified PAM (special liquid PAM solutions) can be applied like the granular form into irrigation ditches or into furrows using the patch method. Emulsified PAM doesn't require quite the vigorous mixing as the granular form, but still needs adequate mixing for dissolving. Emulsified PAM is more voluminous than dry forms, but has an easier time dissolving and is the only form of PAM that should be used for sprinkler irrigating systems, due to greatly reduced the risk of clogging the lines.

[0025] The solid formulation of PAM is placed in an area where turbulence is occurring. The action of the water slowly dissolves the polyacrylamide into the flowing water. The only way to control the amount added into the water is to control where the solid PAM is placed and how long it is left in the water. Calibration for dispersion rate has not yet been determined, so trial and error is the current method used.

[0026] PAM blocks (or cubes) are usually placed in wire baskets in flowing ditches at turbulent points. The wire baskets need to be secured to the edge of the ditch to avoid washing of the blocks down the ditch. The blocks slowly dissolve, releasing small amounts of PAM into the water. Of the three forms PAM blocks may not perform as well as liquid or granular PAM in furrow irrigation. PAM blocks, however, have been useful for treating settling ponds to accelerate water clarification and promote flocculation. They can also be used to dose concentrated runoff areas on fields that otherwise cause uncontrolled erosion.

[0027] Adding polyacrylamide to water is much different than adding most other materials. For example, if a cup of salt water is added to a gallon of water and stirred, the salt will, in a short period of time, dissolve. However, when polyacrylamide is added to water, turbulence is necessary to ensure adequate mixing. Without adequate mixing, the polyacrylamide will not immediately dissolve and PAM globules will form. In time, these globules will find their way to the field and can be seen floating down the furrow. Although not as likely, globules do still occur with injector system use. If PAM is being applied with a center pivot, sprinkler nozzle, plugging may occur if the PAM solution is not well mixed.

[0028] The application method depends on the material selected. Granular PAM requires some form of augured metering system. Solid blocks should be placed in a wire basket and secured to the side of the ditch to avoid washing the block downstream. Liquid PAM can be metered directly from the container into an open ditch or through an injector pump into a pipeline.

[0029] If adding either liquid or dry PAM to an open ditch, the discharge point is kept at least 2 feet away from the flowing water. Small droplets of water can cause the PAM to clog at the outlet and stop flow. If turbulence in the water is causing splashing, the applicator is moved away so that the water does not contact the container or move the turbulent flow downstream.

[0030] Another concern, is the type of water used for irrigation. Because polyacrylamide attaches to the soil particles and binds them together, water containing a lot of sediment may result in sediment settling out before water is diverted into the furrows. In general, this does not affect PAM's effectiveness, but with extremely sediment-laden ditch water, sediment may build up and restrict flow in the supply ditch. This is also a concern for underground transport pipes. If the water velocity in the pipe is insufficient to lift the accumulated sediment, pipe flow may be restricted. Though the pipe flow rate is reduced, the pipe is not likely to plug completely, since as the sediment decreases the pipe's inside diameter, water velocity increases.

[0031] Different soil textures and field slopes can give different results when receiving equal quantities of PAM. One can start with the 10 ppm rate and increase or decrease the concentration based on the clarity of the runoff leaving the field.

[0032] For maximum effectiveness, thoroughly mix PAM with the irrigation water before application. In an open ditch, let the water pass over at least one drop structure or some ditch obstruction to cause turbulence before water is diverted into the furrows. In an earthen ditch, a drop dam will suffice; in a concrete ditch, boards can be used to create the turbulence. In some cases a drop is created in order to adequately mix the material in water. In gated pipe, the pipe swirling action will generally cause enough mixing within the first 2-3 pipe joints. If pressure in gated pipe is relatively low, 3 feet or less, a Krause Box can be used to create a drop structure in the pipeline.

[0033] Regardless of what form of PAM is supplied to the farmers (dry material, concentrated material, or pre-mixed stock solution) it is important to provide aggressive mixing (agitation) at the point of application of PAM to the water sources. The agitation requirement increases as the concentration of stock solution increases and is greatest for use of direct dry PAM application. Agitation should be provided by use of a stream drop and multiple flow obstructions near the point of injection. With vigorous turbulent flow 25-50 ft of ditch canal should be allowed for stock solution mixing before the first siphon tube withdrawal or gate. Dry PAM may need longer ditch runs for adequate mixing. If using gated pipe, the first length of gated pipe after the point of PAM injection should have one or two baffles to enhance mixing. PAM should not be added upstream from weed screens or filters of any kind. Heating of water of stock solution greatly enhances PAM dissolution and mixing.

[0034] The furrow is considered treated once the water reaches the end of the field, and additional polymer is normally not required for that irrigation. In many cases, producers have found that, rather than applying PAM until water advances to the end of the field, protection is adequate by applying PAM only until water advances 50 percent or less of the field length. The advantages are erosion control in the top portion of a field, reduction of sediment deposits in the bottom portion of the field and reduced application costs.

[0035] Because polyacrylamide attaches itself to the soil near the surface, cultivation or ditching after PAM application results in loss of effectiveness. PAM should be reapplied after cultivation or ditching disturbs the soil surface. Once applied, PAM is not effective all season long. However, after the initial application, PAM does continue to offer some erosion control during subsequent irrigations. Factors, such as soil type, field slope and irrigation furrow stream size, will determine the long-term effectiveness of a single PAM application.

[0036] Inadequate mixing of PAM may result in highly concentrated PAM being applied in the first few furrows and insufficient PAM in the furrows furthest from the point of injection.

[0037] The use of automated timers or liquid shutoff valves can be problematic for controlling PAM injection because it is difficult to accurately predict furrow advance time. If advance time is slower than expected, the bottom portion of the fields will not be treated with PAM. If furrow advance is faster than expected more PAM than necessary will be applied and PAM losses in runoff water could occur.

[0038] If using PAM in sprinkler irrigation, the pipes must be pressurized to be sure water is delivered before injecting PAM into the flow. This protocol assures that PAM does not build up in sprinkler lines before water enters the pipes (which would violate the caution of not adding water to PAM). Benefits of using PAM with sprinkler irrigation are much less dramatic than with furrow irrigation. Applying 2-4 lb PAM per acre can reduce erosion and increase infiltration during the irrigation under some conditions. However, beneficial effects last for only one or two irrigations.

[0039] PAM treatment has usually been by injection of small amounts of concentrated stock solutions into the irrigation water supply. There is some indication that direct powder addition may be feasible, but the concept has not been extensively tested. PAMs are applied via irrigation water to only that small part of the soil that play a role in the physical processes of erosion, sealing and crust formation.

[0040] Water-applied PAM increases soil cohesion and strengthens the aggregates it contacts in the furrow by binding exposed soil particles together more securely. This greatly reduces detachment and transport of sediments in irrigation runoff. Soil erodibility at the soil water interface is reduced by improved inter-aggregate bonding and better maintenance of surface roughness. PAM also acts as a settling agent. It flocculates (clumps together) the fine particles. If an irrigation is not adjusted, over-wetting of the upper and/or underwatering of the lower ends could be worsened.

[0041] Most states require that agricultural chemicals (including soil amendments such as PAM) meet safety and state labeling requirements. The PAMs currently labeled are water soluble, anionic (11-20%), high (10-15 million) molecular weight compounds meeting EPA and FDA monomer limits below 0.05%. PAM is available in several forms: dry powder or granules containing 80-95% active ingredient (AI); inverse oil-emersion liquid concentrates containing 30-50% AI (PAM is dissolved in water droplets that float in an oil matrix); and pre-mixed PAM-water solutions containing <3% PAM.

[0042] At a minimum PAM should be used on the first irrigation and when soil is disturbed by traffic and/or cultivation. Additional applications at or below label amounts may be considered to provide complete erosion control for the entire season. If PAM is applied in the first irrigation and subsequent irrigations have no PAM in the water, then erosion control and infiltration effects can be expected to decline approximately 50% with each non-treated irrigation. Thus, by the third irrigation, little effect remains. For those crops in which erosion naturally subsides during mid season, PAM need not be applied after the natural erosion reducing properties ensue.

[0043] Polyacrylamide (PAM) is a long-chain molecule commonly used to clean waste water. To date, the primary market for this compound has been municipal wastewater treatment facilities. It makes the fine solids in treated water glom onto one another, until they become big enough to settle out or be captured by filters to make sewage sludge.

[0044] PAM seeks out and binds to the broken edges of clay particles, which carry a negative charge. By increasing the cohesiveness of soil particles on the soil surface of a field, PAM makes dirt more resistant to the highly erosive shear forces exerted by water flowing over it. This binding is referred to as flocculation. Flocculation is used to describe the action of polymeric materials which form bridges between individual particles. Bridging occurs when segments of a polymer chain adsorb on different particles and help particles aggregate. Flocculants carry active groups with a charge which will counterbalance the charge of the particles. Flocculants adsorb on particles and cause destabilization either by bridging or charge neutralization. An anionic flocculent will usually react against a positively charged suspension (positive zeta potential). That is the case of salts and metallic hydroxides. A cationic flocculant will react against a negatively charged suspension (negative zeta potential) like silica or organic substances.

[0045] The most common polymers are those based on polyacrylamide, which is a nonionic polymer. Their effect is due to bridging between particles by polymer chains. Polymers can be given anionic character by copolymerizing acrylamide with acrylic acid. Cationic polymers are prepared by copolymerizing acrylamide with a cationic monomer. All available acrylamide based polymers have a specific amount of ionic monomer giving a certain degree of ionic character. They have a specific average molecular weight (i.e. chain length) and a given molecular distribution. For each suspension, a certain degree of anionic, cationic or nonionic character is beneficial. Usually, the intrinsic flocculating power increases with the molecular weight. Polyacrylamides have the highest molecular weight among the synthesized industrial chemicals in the range of 10-20 millions. Other polymers display specific properties and are used under specific conditions. They are mostly: Polyethylene-imines, polyamides-amines, polyamines, polyethylene-oxide, sulfonated compounds.

[0046] Anionic PAM are “Off the Shelf” Industrial Flocculants used extensively for: potable water treatment, dewatering of sewage sludges, washing and lye-peeling of fruits and vegetables, clarification of sugar juice and liquor, adhesives and paper in contact with food, animal feed thickeners and suspending agents, cosmetics, paper manufacturing and various mining and drilling applications.

[0047] U.S. Pat. No. 6,357,176 relates to a soil and grass seed-less sod precursor containing a non-woven bio-cellulosic fiber mat and grass sprigs. The sod precursor can be used to produce a soil-free sod which is useful for manufacturing athletic fields, golf courses and lawns. The mat may contain other materials in addition to the bio-cellulosic fiber. The mat may contain other types of fibers, such as wood fibers or synthetic organic fibers. Wood fibers may increase the water retention of the mat. Examples of organic fibers include acrylic, cellulose ester, elastomeric, olefin, polyester, polyamide and polyvinyl alcohol fibers. A synthetic organic polymer may function as a binder. The mat may also contain non-fibrous polymers, such as polysaccharides, proteins, polyacrylamide and other water retention agents. The prior art patent uses polyacrylamide to increase water retention of the mat.

[0048] U.S. Pat. No. 5,900,038 relates to a cultivation substrate and method of preparing the same. The cultivation substrate contains comminuted plants selected from among knot grass, C4 plants and plants of the cannabis and Dicksonia genuses, and is suited as a peat substitute. During the comminution process, or thereafter, additives may be added, depending on the later use of the cultivation substrate. Polyacrylamide granules, clay mineral mixtures, ground lava rock, pumice, bentonite, sand, waste paper, fly ash from brown-coal combustion, brown-coal waste and all kinds of fertilizers are suited as additives. Polyacrylamide granules improve the cultivation substrate of the invention in that it possesses a high water storing capacity for the mulch. Gelling cross-linked polyacrylamide granules, as are e.g., obtainable under the name Polywater-Aqua-Plus from Polyplant GmbH, Xanten, are especially advantageous. This prior art patent uses polyacrylamide to increase the water storing capacity of the mulch.

[0049] U.S. Pat. No. 4,337,117 relates to a synthetic sheet material resistant to decay by fungus and other microbial organisms and useful in shoe construction, mulch papers and the like. The material comprises a uniform distribution of cellulose and optionally synthetic fiber within a matrix or binder and is formed from a furnish of the fibers; a metallic quinolinolate which lends the material decay resistant; a polymer colloid such as an acrylic latex which prevents the coagulation of the subsequently added elastomeric binder by the metallic quinolinolate; and a cationic polymer which acts as a retaining agent for the metallic quinolinolate in the synthetic sheet material. The decay resistant sheet material is formed generally by a papermaking process. The cationic polymer can be polyacrylamide polymers. The polyacrylamide is used to make the sheet material decay resistant.

[0050] U.S. Pat. Nos. 5,429,741 and 5,641,458 relate to methods for treating sludge with processed cellulose material combined with another material, e.g., a surface active agent, a detergent, a surfactant, a polymer and/or an organic polymer. Cellulose flakes and a method for making them are disclosed. They can be used for animal litter or bedding, food or fertilizer. Methods for absorbing, removing, and for cleanup of a first liquid floating on or in a second liquid are disclosed, the method employing absorbent pellets. A typical surfactant useful in sludge conditioning includes emulsions such as polyacrylamide. This prior art reference used the PAM as a surfactant for the sludge treatment.

[0051] U.S. Pat. No. 5,456,733 relates to a process for producing novel mulching pellets from waste paper scrap by incorporating particulate water-insoluble, swellable, gell-forming polymer into the pellet-forming composition. The formed pellets swell and disintegrate after being spread and impregnated with water, to increase their area of ground coverage, to release any included nutrients or seeds, and to deposit polymer particles having water-absorbing properties.

[0052] The invention relates to a method for producing dry extruded mulching pellets, containing particulate waste paper and a swelling agent, capable of application by means of simple spreading devices and being highly water-absorbent and water retentive. Upon impregnation with applied water or rain, the pellets swell, expand and disintegrate to increase their area of ground coverage and provide a water-absorbing surface covering which prevents water run-off and which helps maintain moisture in the soil. The polyacrylamide increases water absorbtion of the pellets. The disintegration or coming-apart of the swollen pellets also increases the exposed surface area of the mulch and facilitates the release of seed and the release of nutrients into the soil to support germination and growth of seed and plants in the soil.

[0053] The most essential feature of the process and mulch pellets is the incorporation of a swelling agent comprising a water-insoluble, swellable, gel-forming, hydrophilic polymeric material, capable of absorbing substantial amounts of water, into pellets comprising waste paper particles. The process consists nearly entirely of particulate waste paper and contains a minor amount by weight, up to 10%, of a water soluble, film-forming, polymeric binder material, and up to 10% of a swelling agent comprising a water-insoluble, water swellable, gel-forming, hydrophobic polymeric material in particulate form, distributed throughout the pellets. The mulch pellets comprise up to about 99% by weight of particulate waste paper, which contains a small amount by weight of a water-soluble film forming binder material such as polyvinyl alcohol and/or cellulose binder material such as carboxymethyl cellulose to bind the wood fibers in the paper making process. The essential additive is the water-insoluble, gel forming, hydrophilic polymer which is uniformly mixed in a powder form. The composition is fed to a conventional pellet mill and pelletized. Examples of polymers are cross-linked polyacrylamide polymers or polyacrylate polymers. This prior art used PAM for the benefit of it's swelling ability of the pellets.

[0054] U.S. Pat. No. 6,349,499 relates to a flaked mulch product having a density similar to that of seed which is to be established, comprising an agglomerated and compacted natural raw material whose density is adjusted to within 50% of the seed. The invention provides lignocellulosic mulch product. To the raw materials may also be added various additives such as dyes and pigments, germination aids, fertilizer, and one or more surfactants and/or water absorbing substances. Surfactants may be added to encourage rapid water uptake and retention. Water absorbent materials such as polyacrylic acids, other polyacrylates, and the like may be used. In some uses, such synthetic polymers may also serve as the binder, e.g., polyacrylic acid, polyacrylamides, and various acrylate, acrylic acid, and acrylamide co-and terpolymers. This prior art reference used PAM as a binder for the mulch product.

[0055] U.S. Pat. No. 6,360,478 relates to a completely biodegradable mulch product which forms a mechanically bonded yet open fiber mulch matrix containing natural fibers and interlockable crimped natural fibers, the crimped natural fibers being crimped by a process which induces a water-resistant permanent crimp.

[0056] A polymer-based water absorbent may be dispersed throughout the fiber mulch to increase the mulch water absorption capacity. The polymer based water absorbent is preferably present at about 5% to 15% of the mulch weight. The water absorbent is preferably a powder such as a polyacrylamide-based copolymer powder that absorbs many times its own weight in water. The polymer-based water absorbent is then dispersed into the fiber mulch to increase its water absorption capacity. The water absorbent is preferably mechanically dispersed into the mixed mulch fiber-crimped synthetic fiber mulch. This prior art reference used PAM for the benefit of the mulch product.

[0057] U.S. Pat. Nos. 5,741,832, 5,779,782 and 5,942,029 relate to mechanically bonded, water absorbent fiber mulch including natural and crimped synthetic fibers that are intimately mixed to form a mechanically bonded fiber mulch. A water-absorbent polymer based material is dispersed throughout the fiber mulch to increase its water absorption capacity. The polymer based water absorbent is preferably present at about 5% to 15% of the mulch weight. The water absorbent is preferably a powder such as polyacrylamide based copolymer powder that absorbs many times its own weight in water. The polymer-based water absorbent is then dispersed into the fiber mulch to increase its water absorption capacity. The water absorption is preferably mechanically dispersed into the mixed natural fiber-synthetic fiber mulch. This prior art reference used PAM for the benefit of the mulch product.

[0058] U.S. Pat. No. 6,460,290 relates to a fully compatible surfactant-impregnated water soluble fertilizer, concentrate and use. Solid surfactant-impregnated, water soluble fertilizer compositions are disclosed together with aqueous concentrates made therefrom. The use of dilute aqueous compositions made from said concentrates to enhance the rewetting of water uniformity and nutrient retention characteristics of initially untreated plant culture media is also disclosed. The fertilizer composition solids are friable and are composed of from 65 to 99 weight percent water-soluble fertilizer; and from 1 to 35 weight percent of a surfactant system comprising water-soluble nonionic surfactant and alkyl polyglycoside in a weight ratio of from less than 2:1 to 1:5. When these solid compositions are dissolved in water to form concentrates having from 20 to 50 weight percent fertilizer, the concentrates are both single phased and extremely stable.

[0059] None of the prior art references uses solid carriers as a means of applying PAM to the soil. In the prior art, PAM has been included in mulch, as a surfactant, as a water absorbent polymer, to alter the state of the mulch (cause expansion of the mulch when watered), increase mulch size to enable the mulch to better cover the seed bed, to increase the mulch's ability to absorb more water to lower the amount of excess water, and hence reduce water runoff and hence soil loss, to hold mulches together as a binder and to increase stickiness of a mulch to keep it in place.

SUMMARY OF THE INVENTION

[0060] The present invention relates to a fertilizer product comprising plant nutrient(s) and soil conditioner(s) to maximize nutrient availability by minimizing nutrient loss due to leaching and runoff. By combining plant nutrients with the proper soil conditioning materials, more of the plant nutrients can be made available for uptake by the targeted plants. It is an object of the present invention to combine fertilizers with soil conditioning materials that have been known to hold the nutrients in the soil in their present state. It is an object of the present invention to combine fertilizers with soil conditioning materials that have been known to bind soil particles together. It is an object of the present invention to combine fertilizers with soil conditioning materials that have been known to be difficult to apply evenly, inexpensively, and/or without water. It is an object of the present invention to define the processes that can be used to produce the fertilizer of the present invention. The water serves as an activation agent or catalyst in that, without it, neither component provides much value to the soil and/or plant life. By combining the fertilizer with amendment materials that condition the soil (such as PAM) in a manner that reduces fertilizer and water loss, the result is an overall reduction in the amount of fertilizer and water required to achieve the desired results. Since PAM binds nutrients and stabilizes soil, it reduces fertilizer leaching and runoff. In effect it works as a PAM dam to fertilizer as it works to maximize the performance of the soil in relationship to the nutrients. PAM acts as an enabler to the soil to improve it's capacity to hold the nutrients in place for use by the plants.

[0061] It is an object of the present invention for both the fertilizer and the soil stabilizer to be released from their granular state by the presence of water. It is an object of the present invention for the soil stabilizer to be PAM.

[0062] It is an object of the present invention for the amended fertilizer to assist in soil conservation, efficient irrigation and fertilization.

[0063] The present invention relates to an amended granular fertilizer product comprising a fertilizer and PAM; wherein the amended fertilizer is applied to soil. It is an object of the present invention for the fertilizer and the PAM to be released into the soil by addition of water through rain or irrigation, or a combination thereof. It is an object of the present invention for the fertilizer to be selected from the group consisting of: carbon, hydrogen, oxygen, nitrogen, phosphorous, potassium, calcium, magnesium, sulfur, boron, chlorine, copper, iron, manganese, molybdenum, zinc, sodium silicon, cobalt, and vanadium, or any combination thereof.

[0064] It is an object of the present invention for the amended fertilizer granule size to range from 1.00-3.35 mm in diameter. It is an object of the present invention for the PAM to be anionic. It is an object of the present invention for the PAM to be neutral. It is an object of the present invention for the PAM to be cationic.

[0065] It is an object of the present invention for the PAM to comprise up to 75% by weight of the total of the product. It is an object of the present invention for the fertilizer to be organic. It is an object of the present invention for the fertilizer to be inorganic. It is an object of the present invention for the fertilizer to be a combination of organic and inorganic.

[0066] It is an object of the present invention for the amended fertilizer to be produced via agitation, liquid, pressure, and/or thermal agglomeration methods. It is an object of the present invention for the granular fertilizer to be applied to the soil through conventional means, such as, spreaders. It is an object of the present invention for the amended granular fertilizer to reduce the need for erosion mats in slope applications prior to establishment of permanent vegetation. It is an object of the present invention for the PAM to increase permeability of the soil. It is an object of the present invention for the PAM to bind to the soil to increase infiltration of the fertilizer and water within the soil.

[0067] It is an object of the present invention for the amended granular fertilizer to improve water infiltration of the soil, thereby improving the soil's ability to absorb water. It is an object of the present invention for the amended granular fertilizer to improve water infiltration of the soil, thereby reducing the amount and/or frequency of water needed for the soil. It is an object of the present invention for the amended granular fertilizer to reduce soil packing and cracking. It is an object of the present invention for the amended granular fertilizer to improve soil tillability. It is an object of the present invention for the amended granular fertilizer to be an anticrusting agent in the soil. It is an object of the present invention for the amended granular fertilizer to reduce rilling of the soil.

[0068] It is an object of the present invention for PAM to bind to the fertilizer to reduce leaching of the fertilizer within the soil. It is an object of the present invention for the PAM to bind to the soil and the fertilizer to reduce runoff of the fertilizer from the soil. It is an object of the present invention for PAM to bind to the soil and the fertilizer to hold the fertilizer in the soil. It is an object of the present invention for the amended granular fertilizer to reduce erosion of the soil, thereby reducing erosion of the fertilizer, thereby reducing fertilizer usage and fertilizer cost per acre. It is an object of the present invention for the amended granular fertilizer to improve water infiltration of the soil, thereby reducing erosion of the fertilizer, thereby reducing fertilizer usage and fertilizer cost per acre. It is an object of the present invention for the amended granular fertilizer to hold nutrients in the soil, thereby reducing fertilizer usage and cost per acre.

[0069] It is an object of the present invention for the amended granular fertilizer to reduce runoff and leaching of microbes in the soil. It is an object of the present invention for the amended granular fertilizer to prevent movement of sediment containing nutrient, pesticides and other matter. It is an object of the present invention for the amended granular fertilizer to comprise aluminum sulfate and/or calcium oxide. It is an object of the present invention for the amended granular fertilizer to reduce total fecal coliform bacteria and fecal strep leaching and runoff from the soil. It is an object of the present invention for the amended granular fertilizer to control erosive forces by holding soils in place and ionically bonding them together to increase particle size.

[0070] It is an object of the present invention for the amended granular fertilizer to improve survival and growth of plants. It is an object of the present invention for the amended granular fertilizer to reduce the time for seed emergence within the soil. It is an object of the present invention for the amended granular fertilizer to improve root growth of plants within the soil. It is an object of the present invention for the amended granular fertilizer to improve crop yield within the soil. It is an object of the present invention for the amended granular fertilizer to when added to the soil to result in a cleaner harvest of root crop. It is an object of the present invention for the amended granular fertilizer to expedite crop maturity.

[0071] It is an object of the present invention for the amended granular fertilizer to increase viability of shrub, tree, and/or vegetable transplants. It is an object of the invention for the amended granular fertilizer to deepen plant rooting in the soil. It is an object of the present invention for the amended granular fertilizer to advance planting dates by drying the soil faster. It is an object of the present invention for the amended granular fertilizer to improve crop quality in the soil. It is an object of the present invention for the amended granular fertilizer to increase germination rates of the seed in the soil. It is an object of the present invention for the amended granular fertilizer to reduce soil-borne diseases within the soil.

[0072] The present invention relates to an amended granular fertilization product comprising: fertilizer and PAM; wherein the amended granular fertilizer is applied to soil, and wherein the PAM serves to improve utilization of the fertilizer by intended plants in the soil.

[0073] The present invention relates to an amended granular fertilizer comprising: a fertilizer and a soil stabilizer; the soil stabilizer selected from the group consisting of: start xanthate, acid hydrolyzed cellulose microfibrils, chitin, gypsum, PAM, hydrocolloidal polysaccharide, acrylic copolymers, sodium acrylate, polyacrylamide, polyethylene-imines, polyamides-amines, polyamines, polyethylene-oxide, and sulfonated compounds, soil conditioners or combination thereof.

[0074] It is an object of the present invention for the amount of soil stabilizer metered to the soil to be controlled by the rate of the granular fertilizer metered to the soil.

[0075] The present invention relates to an amended granular fertilizer comprising: a fertilizer and a soil stabilizer; the soil stabilizer selected from the group consisting of: a material that was previously treated with an ingredient that has soil stabilizing properties, or a material that was derived from potable water treatment, dewatering of sewage sludges, washing and peeling of fruits and vegetables, clarification of sugar juice and liquor, adhesives and paper in contact with food, animal feed thickeners and suspending agents, cosmetics, paper manufacturing, various mining and drilling applications or a combination thereof.

[0076] The present invention relates to a method of reducing amounts of fertilizer required for successful plant growth comprising; applying to soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and the PAM into the soil.

[0077] The present invention relates to a method of improving soil penetration comprising; applying to the soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and PAM into the soil.

[0078] The present invention relates to a method of reducing soil erosion comprising; applying to the soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and the PAM into the soil.

[0079] The present invention relates to a method of reducing fertilizer runoff and leaching comprising; applying to the soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and PAM into the soil.

[0080] The present invention relates to a method of conditioning the soil comprising; applying to the soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and PAM into the soil.

[0081] The present invention relates to a method of treating soil with an amended granular fertilizer comprising; applying to the soil by conventional application equipment an amended granular fertilizer. The amended granular fertilizer comprises fertilizer and PAM. Water is added to the amended granular fertilizer, releasing the fertilizer and PAM into the soil.

[0082] The present invention relates to a method of applying an amended granular fertilizer to soil comprising: adding granular fertilizer to a soil stabilizer. The granular fertilizer is applied to the soil. Water is applied to the granular fertilizer, releasing the soil stabilizer out of the granular fertilizer and into the soil.

[0083] The present invention relates to a method of applying cross-linked polyacrylamide to soil comprising: adding cross-linked polyacrylamide to a granular fertilizer. The granular fertilizer is applied to the soil. Water is applied to the granular fertilizer, releasing the cross-linked polyacrylamide out of the granular fertilizer into the soil.

[0084] The present invention relates to a granular fertilizer used to apply cross-linked polyacrylamide to soil comprising a granular fertilizer and cross-linked polyacrylamide. It is an object of the present invention for the granular fertilizer to increase the lateral root system of plants in the soil.

[0085] The present invention relates to a method for applying PAM to soil wherein PAM is precisely intermixed, impregnated and/or applied to solid carriers. The solid carriers can be comprised of organic and/or inorganic materials that can be applied to soil. These materials may contain fertilizers, soil amendments, soil conditioners, and/or waste products. The solid carrier can be produced by agglomeration. Other terms commonly used to describe agglomeration is granulation and compaction as they both relate to particle size enlargement. The solid carrier acts as a delivery system for the PAM. By controlling the rate of solid carrier metered to the soil, you in turn, control the amount of PAM metered to the soil. The present invention relates to any solid carrier that can be applied through conventional means, such as, spreaders. In a preferred embodiment, these industries include agricultural and horticulture. PAM is not easily applied to the soil. It is currently applied via irrigation systems or in it's dry, granular form. Given it's low rate of application, challenges are many.

[0086] The present invention relates to adding PAM to a solid carrier, applying the solid carrier to the soil; applying water to the solid carrier; and leaching PAM out of the solid carrier into the soil. The water can be natural in the form of rain or applied by man made means. It is an object of the present invention for the PAM to be in a dry granular form. It is an object of the present invention for the solid carrier to comprise a mulch or fertilizer. It is an object of the present invention to add fertilizers and/or soil amendments to the solid carrier. It is an object of the present invention for the solid carrier to comprise fibrous material. It is an object of the present invention for the solid carrier to be in the form of a granule, extruded pellet, woven mat, flake and/or formed bale and or size reduced particle. It is an object of the present invention for the solid carrier to contain a seed. It is an object of the present invention to add pesticides or herbicides to the solid carrier. It is an object of the present invention to add fertilizer to the solid carrier. It is an object of the present invention for the solid carrier used to apply PAM to soil to comprise mulch and PAM. It is an object of the present invention to add aluminum sulfate and/or calcium oxide to the solid carrier. The addition of these elements with PAM assists in slowing down the loss of phosphorous in runoff.

[0087] The present invention relates to a method for applying a soil stabilizer to the soil comprising adding a soil stabilizer to a solid carrier and applying the solid carrier to the soil. Water is applied to the solid carrier which then releases the soil stabilizer out of the solid carrier into the soil. It is an object of the present invention for the soil stabilizer to be selected from the group consisting of: start xanthate, acid hydrolyzed cellulose microfibrils, chitin, gypsum, PAM, hydrocolloidal polysaccharide, acrylic copolymers, and/or sodium acrylate, and any combination of the above.

[0088] It is an object of the present invention for the soil stabilizer to be selected from the group consisting of: polyacrylamide, polyethylene-imines, polyamides-amines, polyamines, polyethylene-oxide, and sulfonated compounds.

[0089] It is an object of the present invention for the solid carrier to be comprised of a material that was previously treated with an ingredient that has soil stabilizing properties.

[0090] It is an object of the present invention for the material to be derived from potable water treatment, dewatering of sewage sludges, washing and lye-peeling of fruits and vegetables, clarification of sugar juice and liquor, adhesives and paper in contact with food, animal feed thickeners and suspending agents, cosmetics, paper manufacturing, various mining and drilling applications.

[0091] It is an object of the present invention for the solid carriers to include mineral elements. It is an object of the present invention for the soil stabilizer to hold mineral elements in the soil. There are 13 mineral elements within the soil that are recognized as being essential for plant growth. The amounts of these elements found within plants vary considerably; hence they are grouped into macronutrients, secondary nutrients, and micronutrients, depending on the relative amounts required for growth. Macronutrients are: Nitrogen Phosphorous and Potassium. Secondary nutrients are sulfur, calcium and magmesium. Micronutrients are iron, manganese, boron, copper, zinc, molybdenum and chlorine.

[0092] The present invention relates to a method of applying cross-linked polyacrylamide to soil comprising: adding cross-linked polyacrylamide to a solid carrier. The solid carrier is applied to the soil. Water is then applied to the solid carrier. This releases the cross-linked polyacrylamide out of the solid carrier and into the soil.

[0093] The present invention relates to a method of applying soil stabilizer to soil comprising adding soil stabilizer to a solid carrier. The solid carrier is comprised of at least 25% particles in excess of 1 mm in diameter. The solid carrier is applied to soil. Water is applied to the solid carrier releasing the soil stabilizer out of the solid carrier into the soil.

[0094] Solid carriers can be made by a number of ways of agglomeration processes, including agitation, pressure, liquid and thermal. Agitation agglomeration includes the methods: tumbling, mixing, granulation, pelletizing, balling, conditioning, and instantizing. Pressure agglomeration includes the methods: briquetting, compacting, extrusion, pelleting, molding, tabletting and isostatic pressing. Liquid agglomeration includes the methods: spray drying, spray granulation, fluid bed granulation, prilling, agglomeration in liquid media, oil agglomeration and globulation. Thermal agglomeration includes the methods: sintering, induration, nodulizing, calcining, drying/solidification, partial gasification/charring.and flaking.

[0095] Agitation agglomeration can use the following equipment: mixers (planetary, cone, ribbon, pintype, drum, counter-current, vertical, paddle, pugmills), Disc pelletizers (pan granulators), drum pelletizers and cone pelletizers. Pressure agglomeration can use the following equipment: roller presses (roll briquetters, roll compactors), piston/ram presses, pellet mills (ring die, flat die), extruders (auger, screw, screen, basket), tablet presses. Liquid agglomeration can use the following equipment: spray dryers, prill towers, spray/fluid bed, granulators, mixers for oil agglomeration. Thermal agglomeration can use the following equipment: sinter strands, travelling grates, rotary kilns, shaft furnaces and drum/belt flakers.

[0096] Solid carriers can also be made via a process of size reduction wherein a material is reduced into smaller particle sizes. In an embodiment, the solid carrier is comprised of materials that are not in a liquid or slurry state.

[0097] Water soluble polyacrylamides (PAMs) have been proposed as soil amendments for various agricultural purposes. Water soluble polymers, generically described as polyacrylamides (PAMs) appear to have a variety of beneficial soil amendment properties, including minimization of water run-off, erosion, and crusting, and stabilization of soil structure. This benefit extends to the general reduction of runoff of fertilizer, pesticide and herbicide.

[0098] PAM is a long chain synthetic polymer that acts as a strengthening agent, binding soil particles together. It is harder for water to move these larger, heavier particles of soil. PAM applied in the irrigation water reduced soil erosion in furrows by over 95 percent, when compared to irrigation without the polymer.

[0099] The present invention allows the user to not have to mix the PAM in the field. The PAM of the present invention does not clog weed screens, filters or narrow siphons as this equipment is not required. Further the method of the present invention allows a user to avoid the risk of handling the dry concentrate. The method of the present invention further avoids the bulkier equipment that has been used to apply PAM in the prior art. The method of the present invention avoids the need for large stock solution volumes which are needed for large fields, or where advance rate is slow; mixing field solution from concentrate which takes considerable time and requires dedicated equipment.

[0100] The method of the present invention avoids the disadvantages of adding a liquid concentrate (oil-emulsion) application directly to the soil. Using the method of the present invention, application is done using standard spreading equipment and need not be sophisticated (compared to that for pre-mixed solutions) to obtain uniform metering rates. The present invention does not require oil and surfactant components that provide no known benefits to crops.

[0101] Though PAM can be incorporated in any physical state into the solid carrier under the current invention, dry PAM is preferred because it impregnates easier into the solid carrier then other forms of PAM. Also dry PAM can be purchased and stored and may be the least expensive form of PAM. Further, by applying PAM by the method of the present invention application equipment does not tend to plug, nor does weed screens and filters. There is no danger from choking from inhalation of PAM dust while filling machine. If one were to apply dry PAM directly to a field, there would be greater PAM losses from the field since there is less control of dissolution. Further by applying dry PAM directly to the soil there is poorer uniformity of distribution than the present invention. The rate of PAM addition must be based on total irrigation inflow rate, erosion potential for a field, and desired injection concentration.

[0102] Application rates of anionic PAM mixtures may need to be adjusted based on soil type, slope, and type of erosion targeted (i.e., wind or water). Anionic PAM mixtures may be applied to steeper slopes when used with other erosion control BMPs such as seed and mulch or erosion mat.

DETAILED DESCRIPTION OF THE INVENTION

[0103] Fertilizer, as described in the Fertilizer Manual (1998) is a material whose main function is to provide plant nutrients. Plant nutrients are elements that are essential for the proper development and growth of plants. These elements typically include carbon, hydrogen, oxygen, nitrogen, phosphorous, potassium, calcium, magnesium, sulfur, boron, chlorine, copper, iron, manganese, molybdenum, and zinc. Criteria for elements to be considered essential are that it must be present for the plant to complete its life cycle, its action must be specific and unable to be replaced by that of another element; and its action must be direct. Other fertilizers include various beneficial plant nutrients (sodium silicon, cobalt, and vanadium) that are not considered essential. These types of beneficial plant nutrients appear to have specific functions in plant nutrition, but do not meet all of the three criteria required for essentiality described above.

[0104] There are inorganic (mineral) fertilizers in which the declared nutrients are in the form of inorganic salts obtained by extraction and/or by physical and/or chemical processes, and there are organic fertilizers. Organic fertilizers which are carbonaceous materials mainly of vegetable and/or animal origin (including manipulated and/or unmanipulated manures) that can be added to the soil. Organic fertilizers are also defined as a material containing carbon and one or more elements, other than hydrogen and oxygen, essential for plant growth.

[0105] Fertilizers can be straight fertilizers (having only one nutrient element) or a compound fertilizer (containing two or more plant nutrient elements). Fertilizers can be in the form of granules, pellets, prills, or crystals and shall be free-flowing. A granular fertilizer is a solid material that is formed into particles of a predetermined size. Granular fertilizers do not include powder (a solid substance in the form of very fine particles), solution fertilizers (liquid fertilizer free of solid particles), suspension fertilizer (a 2-phase fertilizer in which solid particles are maintained in suspension in the aqueous phase), slurry fertilizer (a fluid mixture that contains dissolved and undissolved plant nutrient materials and required continuous mechanical agitation to assure homogeneity). In the United States, the typical size range of granular fertilizer products is about 1.00-3.35 mm. Granules are relatively spherical particles produced by enlarging small particles through successive deposition of a liquid or slurry material, which solidifies on the surface through crystallization and/or drying (called granulation, agglomeration, accretion or in reverse, crushing). Different processes are used depending on the material being granulated. Prills are a granule obtained by solidification of droplets of fertilizer or by crystallization under special conditions. Crystals are particles that have flat side and sharp edges and corners.

[0106] In addition to water and sunlight, the soil covering the earth's surface is a basic support system for all plant life. Soil serves to provide water and nutrients for growth. Soil conditions can be altered by external means (i.e., human interaction) in a fashion to improve it's performance in these areas. One of the manners in which this is accomplished is by adding soil conditioners to the soil.

[0107] Soil conditioners' main function is to improve the soil's physical and/or chemical properties and/or their biological activity. Soil conditioners are also referred to as soil amendments and can be organic or inorganic.

[0108] Next to photosynthesis, many plant scientists consider the ability of soil materials to exchange cations (positively charged ions) to be the most important phenomenon that enables soils to support plant growth. Minerals and organic materials have permanent negative charges that give them the ability to adsorb and desorb cations by exchange. This phenomenon reduces susceptibility of these ions to leaching and buffers their concentrations in soil solution to provide ions for growth. There are many soil conditioners that have the ability to bind soil particles together to form larger, stable aggregates. They also affect the nutrient and water-holding characteristics of soils and the physical handling characteristics of soil.

[0109] An amended fertilizer is a fertilizer that is treated with an amendment to reduce fertilizer loss and/or improve the fertilizer utilization within soil. The amendment may be applied to the fertilizer via conventional agitation, pressure, liquid, and/or thermal agglomeration processes.

[0110] Many fertilizers have been coated with various amendments (i.e. polymers) to control the release rate of the nutrients into the soil. The desired outcome at times is commonly referred to as a slow-released fertilizer or controlled release fertilizer. In other applications, a substance is added to a fertilizer to extend the time that the nitrogen component of the fertilizer remains in the soil in the ammoniacal form. Another application has a complex chemical substance that has the effect of killing or temporarily reducing the activity of the soil bacterium Nitrosomonas, which is responsible for the conversion of ammonium-nitrogen in the process of nitrification. The effect is similar to that of slow-release fertilizers. These are referred to as nitrification inhibitors and are added to nitrogen products before application. None of the prior art references combine the fertilizer with a soil conditioner that has been known to hold the nutrients in the soil in their present state; have been known to bind soil particles together; and/or have been known to be difficult to apply evenly, inexpensively, and/or without water.

[0111] Many amendments have been known to hold the nutrients in the soil in their elemental state and/or been known to bind soil particles together. Many of them have been used in agriculture for years, but are difficult to apply evenly, inexpensively, and/or without initial dilution in water.

[0112] In an embodiment, a cross-linked polyacrylamide is added to the solid carrier which is then applied to the soil. Water is then applied to the solid carrier which releases the cross-linked polyacrylamide from the solid carrier into the soil. Superabsorbent cross-linked polyacrylamide are used in several types of applications for absorbing aqueous solutions. The polymers can be used for solidifying any water based material. These polymers act as a reservoir of water that is available to plants on demand, reducing plant shock and the effects of drought. When added to soil, plant roots grow directly into the water-swollen polymers, tapping the reserve as needed. An example of such a polymer includes a cross-linked potassium polyacrylate/polyacrylamide copolymer.

[0113] In an embodiment, a soil stabilizer is added to a solid carrier which is then applied to the soil. Water is applied to the solid carrier which then releases the soil stabilizer out of the solid carrier into the soil. Examples of soil stabilizers are: start xanthate, acid hydrolyzed cellulose microfibrils, chitin, gypsum, PAM, hydrocolloidal polysaccharide, acrylic copolymers, and/or sodium acrylate, and any combination of the above. Three polysaccharides (start xanthate, acid hydrolyzed cellulose microfibrils and chitin) have been shown to reduce soil loss. Polysaccharides are long chains of monosaccharides linked by glycosidic bonds. Three important polysaccharides, starch, glycogen and cellulose are composed of glucose. Starch and glycogen serve as short term energy stores in plants and animals, respectively. The glucose monomers are linked by glycosidic bonds. These are biodegradable polymers that have similar properties to water soluble PAM. In an embodiment of the present invention these polysaccharides are used as an additive or substitute to PAM.

[0114] Gypsum when combined with PAM is effective in reducing both soil loss and water runoff. Overall results indicate that a timely combination of these surface treatments such as tillage, mulch, canopy, gypsum, and PAM are useful and effective in combating water runoff and soil loss on cultivated lands. In an embodiment of the present invention, gypsum is used as an additive to the PAM of the present invention.

[0115] Guar gum is a natural high molecular weight hydrocolloidal polysaccharide composed of galactan and mannan units combined through glycosidic linkages which may be described chemically as galactomannan. It has been commonly used as a soil stabilizer for many years. It is a white to yellowish white powder. It is dissolved in cold or hot water, and forms a slime of high viscosity. In an embodiment of the present invention guar gum is used as an additive or a substitute for the PAM of the present invention.

[0116] Acrylic copolymers are commonly used as soil stabilizers. In addition, sodium acrylate is commonly combined with water soluble PAM and used as a soil stabilizer. An acrylate is a salt or ester of propenoic acid. In an embodiment of the present invention these are used as additives or substitutes of PAM.

[0117] In an embodiment, soil stabilizer is added to the solid carrier, wherein the solid carrier is comprised of at least about 25% particles in excess of lmm in diameter. The solid carrier is applied to the soil. Water is then applied to the solid carrier which releases the soil stabilizer out of the solid carrier into the soil. When dealing with polymers and fertilizers, soil amendments, soil mulches, and carriers, particle size matters as it affects agronomic response, granulation and process performance, and blending, storage, handling and application properties. In general, the smaller the particle size, the more rapidly dissolution occurs. Before about 1950, almost all fertilizers were produced as relatively fine powders or small crystals. As a result, fertilizers usually were dusty during handling and very susceptible to hard caking during storage in piles or bags. The growth of granulation (agglomeration) resulted in great improvement in storage, handling and application properties. This growth was paralleled by improvement in application equipment that took advantage of the better flow properties and reduction of caking in granular products. In the United States, the typical size range of granular fertilizer products is around 1-3.35 mm. In European countries and Japan, sizes are generally in the 2-4 mm range. In a preferred embodiment, the solid carrier is in the size range of about {fraction (5/16)} to about 30 mesh (0.0234 inches or 600 microns).

EXAMPLE

[0118] A laboratory test was conducted to impregnate a fertilizer granule (DAP) with PAM at a rate of 43 to 1. The raw materials were precisely measured and fed into an ammoniator-granulator along with the metered dry PAM particles. The granulator successfully agglomerated the finished solid carrier. The solid carrier was then dried and screened to size. The solid carrier was then metered to the turf stand with a conventional drop spreader. After watering the solid carrier successfully delivered the precise amount of nutrient and PAM to the turf stand.

	Number	Date	Country
Parent	10271072	Oct 2002	US
Child	10379643	Mar 2003	US

Granular fertilizer

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