Background technology
The present utilization ratio of China's chemical fertilizer is very low, and nitrogen, phosphorus, potash fertilizer are respectively 25% to 30%, 10% to 25%, 35% to 50%.China's per hectare chemical fertilizer usage quantity reaches 240 kilograms at present, and the unit surface rate of fertilizer application is 1.6 times of world's mean vol.China's chemical fertilizer utilization ratio is significantly less than developed country's level, and the service efficiency of chemical fertilizer is downward trend.The whole nation is annual to reach 1,650 ten thousand tons because of fertilising causes nitrogen to run off, and nearly hundred billion yuan of financial losses are importantly brought serious environmental problem:
One, chemical fertilizer is to the pollution of water body; Thereby migration takes place under the leaching of water the chemical fertilizer in the soil flows into rivers, lake or enters underground water, constitutes the main non point source of pollution of body eutrophication.
Two, chemical fertilizer is to atmospheric pollution; Mainly show the direct pollution that the ammonia, greenhouse gases etc. of discharging when using chemical fertilizer, chemical fertilizers production or storing cause.
Three, to the pollution of agricultural-food; Chemical fertilizer is the most alarming to be the accumulation problem of nitrate.Be grown in the plant of using on the chemical fertilizer soil, can absorb nitrate in the soil by root system.If excessively fertilising can cause a large amount of Nitrate Accumulation in leaf, stem and root, the mankind and livestock that food is got in harm.
Four, chemical fertilizer is to the pollution of soil; On the one hand, heavy dressing easily causes soil compaction.On the other hand, heavy dressing may cause the minimizing and the elimination of responsive biological species in the soil, destroys the agricultural ecological balance, influences species diversity.
Five, to the murder by poisoning of farm crop; The raw material of producing chemical fertilizer contains some micro-compositions, some chemical fertilizer also can be sneaked into various trace ingredientss in process of production, outside nutritive ingredients such as cupric, manganese, boron, molybdenum, zinc in the phosphatic rock, also have arsenic, cadmium, chromium, fluorine, mercury, nickel, lead etc. to the deleterious composition of plant.Excessively fertilising can cause the enrichment in soil of above poisonous element, thereby influences the growth of farm crop.
In recent decades, countries in the world a kind of similar phenomena almost occurs simultaneously in the production of chemical fertilizer (mainly being nitrogenous fertilizer) with in using: rate of fertilizer application rapidly increases, but the not corresponding quick growth of grain yield.
In general, the corresponding absorption rate of dividing of farm crop, S-shaped substantially in a vegetative period, promptly begin slowlyer, accelerate greatly subsequently, slack-off gradually again later on.If certain fertilizer can be supplied with nutrient by this regulation of fertilizer requirement of crop, the nutrient that discharges is very fast to be absorbed by crop, and the fertilizer nutrient loss will reduce greatly so, and utilization ratio will improve greatly, the ultimate aim of Here it is release fertilizer.Since nineteen forty-two, urea-formaldehyde fertilizer was obtained patent, over 78 years, slow release fertilizer has rapid progress, developed into again in several years controllable release fertilizer (controlled availability fertilizers, CAFS) and some practical application in agriculture production.Particularly after the seventies, carried out big quantity research abroad, the release fertilizer of selling with commerical prod on the market has reached tens of kinds now.
The company and the product of the production release fertilizer that the world today is more famous have: Sierrachemical (U.S., Holland, trade(brand)name " Osmocote "), Asahi chemical industry (Japan, trade(brand)name " Long ", " High control "), Chisso-Asahi (Japan, trade(brand)name " Lpcote ", " Nutricote ", " Meister "), BASF, Hydro (Germany) etc.The U.S., Japan, existing 39 families of West Europe slow release fertilizer factory, annual production 500000 t are equivalent to about 1% of fertilizer amount, but should be with the speed increase of 3-5%.The price of external release fertilizer is generally 3-9 times of common fertilizer.
Slowly-releasing, controlled release, composite highly effective and environmental friendliness are the general trends of fertilizer development, and developing and use full nutrition release and release control fertilizer is one of ultimate aim of fertilizer science.The U.S., Japan and every Western Europe country, just be devoted to applicating modern times technology, promote to produce, study the combination of (balance fertilizing) and use, development high density high-quality composite fertilizer special (developed country accounts for 80% of fertilizer variety, and China is less than 10%) and slowly-releasing, release and release control fertilizer.
Late 1960s, Nanjing Soil Inst., Chinese Academy of Sciences is in the research of China's early start slow-release nitrogen fertilizer.Successively succeeded in developing bicarbonate of ammonia granulated fertilizer and be the slowly-releasing carbon ammonium and the slow-release carbamide of main coated fertilizer with the mass-produced fused(calcium magnesium)phosphate of China.After this, ecological Studies institute is used in province academies of agricultural sciences such as Shanghai Chemical Research Inst, Hunan, Fujian, Shandong, Zhejiang, Shenyang, northwest water is protected the research that institute, Guangzhou Nitrogenous Fertilizer Factory and Zhengzhou Polytechnical Univ. etc. have carried out this respect.In the recent period, Beijing agricultural academy of sciences and Agricultural University Of South China have carried out new trial aspect coated fertilizer, begun pilot scale.A kind of novel sustained release fertilizer that Nanjing soil institute of the Chinese Academy of Sciences in 2004 utilizes polyacrylamide and chitosan coated urea to make.The price of China's slow release fertilizer generally is higher than common fertilizer 10-15%.Up to the present, but China does not also have the appearance of release and release control fertilizer, and this will influence the international competitiveness of China's next century on fertilizer industry and agricultural undoubtedly.
Present stage, the research level of China's controlled release fertilizer, production and application scale are bigger with state's gaps such as U.S., days.No matter the combination of polymer coating/urease inhibitor and nitrification inhibitor still be the environment viewpoint from agronomy, all can yet be regarded as and regulates the effective bio-chemical pathway of urea N conversion.But too high its big area that limits of slow-release fertilizer complex manufacturing technology or production cost is promoted.The more important thing is: do not absorb corresponding to ' intelligence ' release no matter the slow-release fertilizer of the sort of explained hereafter is also accomplished the release of nitrogen and crop S type.
Summary of the invention
The purpose of this invention is to provide a kind of Active earth and flocculating agent, adsorbent composite material nitrogenous fertilizer process for fixation, be to utilize active mineral soil (attapulgite) and macromolecular material (chitosan and polyacrylamide) matrix material that the nitrogen in the nitrogenous fertilizer is fixed in the soil (plant rhizosphere), absorb nitrogen according to self budding demand by plant.So-called ' fixing ' is exactly the synergy of utilizing above-mentioned materials, build bridge, volume is swept, net is caught and electric charge absorption makes wetland form that the molecule grid adsorbs and fixing ammonia-state nitrogen ion, stop its loss or volatilization and absorbed the raising chemical fertilizer utilization ratio by farm crop in order.This method not only can effectively improve utilization rate of nitrogen fertilizer, and reduces the pollution of area source and the protection agroecological environment of body eutrophication.
Technical scheme of the present invention is as follows:
Active earth and flocculating agent, adsorbent composite material nitrogenous fertilizer process for fixation, it is characterized in that nitrogenous fertilizer and active earths, flocculation agent, sorbent material mixing are executed crop root, this three kinds of materials synergy and by build bridge, volume is swept, net is caught and electric charge absorption is flocculated the wetland colloid, form the molecule grid, ammonia-state nitrogen absorption is fixed in the flocs unit, is made for the thing growth needs and absorbs.Described active earths is attapulgite, sepiolite, and flocculation agent, sorbent material are polyacrylamide, chitosan.
Active earth and flocculating agent, adsorbent composite material nitrogenous fertilizer is fertilizer fixedly, it is characterized in that being made up of nitrogenous fertilizer and sustained release dosage, and described sustained release dosage is mixed composite by a certain percentage by chitosan, polyacrylamide, attapulgite, and its formulation by weight is:
Chitosan 1
Polyacrylamide 4-8
Attapulgite 150-500.
Above-mentioned fertilizer is characterized in that the formulation by weight of described sustained release dosage is:
(1), chitosan 1
Polyacrylamide 4-5
Attapulgite 150-300
More than prescription is applicable to sandy soil;
(2), chitosan 1
Polyacrylamide 7-8
Attapulgite 250-500
More than prescription is applicable to loam;
(3), chitosan 1
Polyacrylamide 4-5
Attapulgite 200-400
More than prescription is applicable to clay.
The ratio of described nitrogenous fertilizer and sustained release dosage is an arbitrary proportion, and the two is mixture or is separately to pack.
Described attapulgite can be replaced by sepiolite.
Described nitrogenous fertilizer is urea or ammonium nitrate.
The described sustained release dosage particle diameter of sandy soil that is applicable to is about 3mm; The sustained release dosage particle diameter that is applicable to loam and clay is about 2mm.
1, the used active mineral soil of the present invention is attapulgite, it is a kind of silicate minerals that contains Shuifu County's magnalium with layer chain-like structure, mineral such as normal and polynite, quartz, rhombspar mix symbiosis, the attapulgite with industrial value of China's discovery at present mainly is positioned at the triangle zone that Soviet Union Anhui has a common boundary, Xuyi, the six directions as Jiangsu, ground such as the Mingguang City in Anhui, Quanjiang are a kind of very important non-metallic mineral resources in China.The molecular formula of its main component is Mg
5(H
2O)
4(Si
4O
10)
2(OH)
2
The fundamental structural unit of attapulgite is that two-layer silicon-oxy tetrahedron and one deck magnesium (aluminium) oxygen octahedra constitute, wherein contain crystal water and the hydroxyl that is in inside configuration, each fundamental structural unit interconnects by four jiaos public Sauerstoffatom, constitute the duct parallel with chain, the sectional area in duct is about 0.37nm * 0.60nm, transition type feature with layer chain-like structure has higher shape ratio.The microstructure of attapulgite is made of three levels, and the one, its basic structural unit one rod crystalline substance.The rod crystalline substance is needle-like, is about 1 μ m~2 μ m, and diameter is 0.01 μ m, belongs to monodimension nanometer material.The 2nd, assemble the brilliant bundle of the rod that forms by the brilliant close parallel of rod.The 3rd, assemble the various aggregates that form mutually by brilliant interfascicular.
Its source is wide, cheap, and has good physico-chemical property:
(1). its can form network structure in wetland, high molecular polymer chitosan and water molecules are fixed on one by one in the grid, when stoping chitosan to run off, can reduce moisture loss effectively, helps water-saving agriculture.
(2). good thixotropy, for example raining or irrigating can not influence its distribution and effect, can alleviate the fertilizer loss that heavy rain or bad irrigation cause to a certain extent like this.
Attapulgite is taken from soil, and use can't cause secondary pollution, or destroys the microstructure of soil.
2, used chitosan is a product behind the chitin deacetylase base among the present invention, is the most basic, the most important derivative of chitin.Chitin has another name called chitin, chitin, and chemistry (1,4)-2-ethanamide by name-2-deoxidation-callose mainly is present in the cell walls of animal shell such as shrimp, crab, pupa and insect and mushroom, phycophyta.The dried shell of segmental appendage class animal contains the 20-50% chitin approximately.The biosynthesizing amount of annual chitin is billions of tons on the earth, is that output is only second to cellulosic natural high moleculer eompound.
Chitosan is as a kind of natural Zeo-karb, in its molecule-NH
3 +And special vesicular structure makes it have good flocculation and adsorption function.Chitosan can not bring secondary pollution to environment with environmental friendliness at occurring in nature by biological degradation, and also have the growth that promotes plant, press down huge sum of money bits effects such as the influence of plant and antimicrobial acivities, be a kind of very ideal fertilizer additive.But because the price of chitosan is higher, its application is restricted.The present invention just utilizes a large amount of cheap active earthss to work in coordination with chitosan as auxilliary agent with fixed attention and plays a role, and can reduce chitosan dosage greatly, saves cost.
3, the used polyacrylamide of the present invention is a kind of linear water-soluble polymers, is one of most widely used kind in the water-soluble polymers.It is formed by monomer polymerizations such as acrylamides, and its molecular chain is very long, and this just makes it build bridge between particle, they are pulled in together and form flco.In addition, have a large amount of side group-amide group on its molecular backbone.The activity of amide group is very big, can produce the derivative of many polyacrylamides with multiple compound reaction.Like this, polyacrylamide not only has a series of derivatives, and has the performance of multiple preciousness, as: flocculation, tackify (thick), surfactivity etc.Because its production technique comparative maturity, price be lower, itself do not have toxicity, so be widely used as flocculation agent at present.
4, chitosan, polyacrylamide and the attapulgite used of the present invention, the three is composite by a certain percentage, this three kinds of materials synergy and by build bridge, volume is swept, net is caught and electric charge absorption is flocculated the wetland colloid, form the molecule grid, ammonia-state nitrogen absorption is fixed in the flocs unit, is made for the thing growth needs and absorbs.To different farm crop, adjust composite fertilizer components ratio ammonia-state nitrogen immobilization phase and farm crop were complementary to the cycle that fertilizer absorbs.Equally, the moisture in the soil also is fixed in the grid of composite fertilizer, and the effect of soil moisture conservation is played in the volatilization of moisture and the minimizing of running off.Like this, not only improve chemical fertilizer utilization ratio, and effectively stop the nitrogen phosphoric to enter underground and surface water, suppressed a large amount of loss of chemical fertilizer and the water pollution that causes.
To sum up, this invention can not only reduce applying quantity of chemical fertilizer and irrigation water use greatly, saves cost and reduces the labour, and can effectively reduce the non point source of pollution of body eutrophication.This technology compound material therefor is environmentally friendly, and each component can be degraded and be utilized by phytomicroorganism, and product itself can not cause environmental pollution or health problem.Technical scheme
Chitosan, polyacrylamide, attapulgite are mixed by a certain percentage composite, at urea or ammonium nitrate (NH
4NO
3) before the production granulation, they are mixed and granulation (particle diameter is the 2-3 millimeter).Thereby can adjust this compound ratio and particle diameter acquisition ideal immobilization effect according to the different soils type.
Also can chitosan, polyacrylamide, attapulgite are mixed by a certain percentage composite after, before fertilising and urea or ammonium nitrate (NH
4NO
3) mixing spreads fertilizer over the fields.
1, sandy soil: urea or ammonium nitrate (NH
4NO
3), chitosan, polyacrylamide, attapulgite be by 1000: 1: 4: 150---1000: 1: 4: 300 is composite, and particle diameter is about 3mm.
2, loam: urea or ammonium nitrate (NH
4NO
3), chitosan, polyacrylamide, attapulgite be by 2000: 1: 8: 250---2000: 1: 8: 500 is composite, and particle diameter is about 2mm.
3, clay: urea or ammonium nitrate (NH
4NO
3), chitosan, polyacrylamide, attapulgite be by 2000: 1: 4: 200---2000: 1: 4: 400 is composite, and particle diameter is about 2mm.
Effect analysis
1, the urea of 85-90% or ammonium nitrate (NH
4NO
3) adding 10-20% active earths and macromolecular material mixture.Press the about 1.3 yuan of calculating of per kilogram mixture, the new type chemical fertilizer cost reduces 0.2 yuan/kilogram.
2, test-results shows that solubility rate, the soil solubility rate of its effective constituent in water reduces 20% and 50% respectively through composite new sustained release chemical fertilizer, and soil continues feeder capability and improves 50%-70%.So the fertilizer efficiency utilization ratio improves 50%-90%; Generally speaking, be reduced to the 30%-60% of conventional fertilizers consumption in every mu of rate of fertilizer application of this ratio; Cost is reduced to traditional 40%-60%; The fertilizer efficiency time lengthening is 2 to 5 times of conventional fertilizers; Irrigation water use reduces 40%-80% than traditional way.
3, aspect ecological,,, help keeping the balance of agroecosystem in order to avoid cause underground and surface water eutrophication and become non point source of pollution harm because this invention can effectively reduce the loss of nitrogenous fertilizer to underground and surface water body.Chitosan, polyacrylamide, attapulgite all are source nature and biomaterial in addition.It is environmentally friendly and can change the physico-chemical property of soil to use back its meta-bolites of can degrading in soil, increases the fertile outlet capacity of containing of guarantor of soil.