AU2021100558A4

AU2021100558A4 - Carbon-coupled stabilized compound fertilizer and preparation method

Info

Publication number: AU2021100558A4
Application number: AU2021100558A
Authority: AU
Inventors: Yuchao Song; Zhanbo WEI; Zhijie WU; Lili Zhang
Original assignee: Institute of Applied Ecology of CAS
Current assignee: Institute of Applied Ecology of CAS
Priority date: 2021-01-28
Filing date: 2021-01-28
Publication date: 2021-04-22
Anticipated expiration: 2029-01-28

Abstract

The disclosure relates to a compound (mixed) fertilizer, and particularly relates to a carbon-nitrogen-coupled stabilized compound fertilizer and a preparation method. Components of the fertilizer include a nitrogen fertilizer (urea-state nitrogen fertilizer), a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor (urease inhibitor and/or nitrification inhibitor) and a carbon source, wherein the nitrogen fertilizer is urea. The phosphorus fertilizer includes calcium superphosphate and double superphosphate. The potassium fertilizer includes potassium chloride and potassium sulfate. A weight ratio of the nitrogen fertilizer to the phosphorus fertilizer to the potassium fertilizer to the biochemical inhibitor to the carbon source material is 1: (0.3-0.5): (0.8-1): (0.001-0.1): (0.1-0.3). In the fertilizer of the disclosure, a certain amount of carbon source material is added into the fertilizer, so that the release time and release rate of the nitrogen fertilizer can be prolonged, the fertilizer effect is slow and stable, the demand of crops on various nutrients in different growth periods can be met, the contradiction between the crop fertilizer demand and soil fertilizer supply can be solved, and the emission of greenhouse gases and leaching loss of nitrogen can be reduced. The disclosure is a novel carbon-coupled stabilized compound fertilizer.

Description

AUSTRALIA Patents Act 1990

COMPLETE SPECIFICATION INNOVATION PATENT CARBON-COUPLED STABILIZED COMPOUND FERTILIZER AND PREPARATION METHOD

The following statement is a full description of this invention, including the best method of performing it known to me:

CARBON-COUPLED STABILIZED COMPOUND FERTILIZER AND PREPARATION METHOD TECHNICAL FIELD

[0001] The disclosure relates to the field of soil and chemical fertilizers, and particularly relates to a stable fertilizer which not only can provide a certain amount of nitrogen source to the soil, but also can avoid the loss and waste of nitrogen caused by insufficient carbon source, fixes the nitrogen source in the soil in a form of nitrogen of microbial biomass and fixed ammonium, promotes the growth of crops, meets various nutrition demands of the crops in various growth and development periods, and also can reduce the emission of greenhouse gases to protect the environment

BACKGROUND OF THE PRESENT INVENTION

[0002] Nitrogen is one of essential nutrition elements for the growth of crops. The application of nitrogen fertilizer plays an important role in increasing the yield and improving the quality of crops, and the application amount of nitrogen fertilizer accounts for about 60% of the total amount of chemical fertilizer. However, the utilization rate of the nitrogen fertilizer in China has decreased gradually. The seasonal utilization rate of the nitrogen fertilizer is only 30%-35%, and the rest nitrogen fertilizer is wasted in various forms. The utilization rate of the nitrogen fertilizer on cash crops reaches 50%-70%. In the planting process of paddy rice field, there are generally situations of large application amount of nitrogen fertilizer, low utilization rate of nitrogen fertilizer, etc. By 2012, the utilization rate of nitrogen fertilizer in the paddy rice field in China was only 30%-40%. According to the forecast of the Food and Agriculture Organization of the United Nations (FAO) in

2015, the worldwide demand on nitrogen fertilizer was approximate to 1.19x108 tons in 2019, with an average annual growth rate of 1.4%, and the annual growth rate of 18% in China. The application amount of nitrogen fertilizer in China surpasses the international average level. At present, the demand on nitrogen fertilizer keeps increasing. The utilization rate of the nitrogen fertilizer is low. It is an urgent problem to increase the utilization rate of nitrogen fertilizer and reduce the loss of nitrogen from the perspective of economic benefit or environmental protection. The production of more efficient stable nitrogen fertilizer has a broad development prospect.

[0003] For the low utilization rate of nitrogen fertilizer, air pollution problem caused by vast emission of NxO and underground water pollution problem caused by leaching loss of nitrogen, the research and production of the stable fertilizer have already made certain progresses. A large number of scientific researches show that controlling the transformation of nitrogen in the soil through a biological and chemical way becomes one of effective ways for increasing the utilization rate of the nitrogen fertilizer. By adding biochemical inhibitor into the fertilizer, the hydrolysis of urea and nitrification of ammonium are slowed down, the content of absorptive ammonium in the soil is increased, the oxidation of ammonium is inhibited, the volatilization of ammonium and emission of greenhouse gases are reduced, etc. The production of stable fertilizer has the advantages of low cost, simple technological process, apparent nitrogen transformation control effect, easy mass production and the like and is widely used and developed in China.

[0004] In farmland ecosystem, nitrogen cycle and carbon cycle in the soil are closely related, and the carbon cycle is limited and influenced by the nitrogen cycle to some extent. In agricultural ecosystem, a dynamic state of carbon and nitrogen in the soil is a complex biogeochemical process including generation, decomposition, nitrification, denitrification and fermentation of organic matters. A carbon-nitrogen

ratio in the soil can reflect a coupling relationship between the carbon and nitrogen in the soil, which plays an important role in evaluating soil quality. In the agricultural production, the carbon shall be increased and the nitrogen shall be decreased, thereby keeping the carbon-nitrogen balance in the soil and the sustainable utilization of the soil. When the C/N in the soil is relatively low, , there is sufficient nitrogen that can be consumed by microorganisms. The nitrogen that is consumed by the microorganisms needs to consume more carbon, while the microorganisms need more carbon to maintain the activity in a case where the nitrogen is sufficient. Therefore, when the compound fertilizer is used, a certain amount of carbon source needs to be applied, so that the loss of nitrogen can be reduced, the utilization rate of nitrogen can be increased, and the nitrogen fixing capacity of the soil can be improved. The nitrification and denitrification intensity of soil is related to the mineralization rate of organic carbon in the soil, the nitrification and denitrification rate is related to total carbon in the soil and highly related to the content of soluble carbon or mineralizable carbon. The input of organic carbon is conducive to the accumulation of nitrogen in the soil. The long-term site-specific experiment shows that the reasonable fertilization can keep or increase the content of organic carbon and total nitrogen in the farmland soil. In the soil of the paddy rice field, the change trend of the content of organic matters and total nitrogen in the soil is similar, and the organic matters and total nitrogen promote and restrict each other and have a good coupling relationship.

[0005] y-polyglutamic acid (y-PGA) has strong hydrophilicity and water retention capacity. When y-PGA is immersed in the soil, a layer of film may be formed on the surface of root hair of plants, which not only has a function of protecting the roof hair, but also is a best transport platform for nutrients and water in the soil to contact the root hair, and can effectively improve the solubility, storage, transportation and absorption of the fertilizer. y-PGA can prevent the precipitation of sulfate, phosphate, oxalate and metal elements, so that the crops can more effectively absorb phosphorus, calcium, magnesium and trace elements in the soil. y-PGA can promote the development of plant root systems, and can enhance the disease resistance. At present, there are a lot of synthesis methods of y-PGA, including a traditional peptide synthesis method, a dimer condensation method, a natto extraction method, a microorganism fermentation method, etc. At present, polyamide urea has already been applied to the planting of vegetables and fruits, which have obtained good economic and environmental benefit.

[0006] Rice, wheat, corn, sorghum and other crops like the nitrogen fertilizer in a form of NH 4+. Applying stable nitrogen fertilizer containing nitrification inhibitor and urease inhibitor can slow down the transformation process of NH 4 +-N to NO3--N, so that a high content of NH 4 +-N in the soil can be kept.

[0007] The loss of nitrogen in farmland soil is serious, the utilization rate of nitrogen fertilizer is low, and different crops have different demands on nitrogen, phosphorus and potassium, so the development of stable fertilizer is in urgent need of a new direction. It is a new research direction to combine nitrogen phosphorus and potassium fertilizer, inhibitor and a carbon source material to produce a novel compound fertilizer, which has great significance in improving the soil fertility, storing a soil nitrogen pool and increasing the crop yield.

SUMMARY OF PRESENT INVENTION

[0008] A purpose of the disclosure is to provide a carbon-coupled stabilized compound fertilizer and a preparation method.

[0009] In order to realize the above purpose, the disclosure adopts a technical solution as follows:

[0010] Acarbon-coupled stabilized compound fertilizer is provided, wherein components of the fertilizer include urea, calcium superphosphate (double superphosphate), potassium chloride (potassium sulfate), biochemical inhibitor and a carbon source (preferably amino acid). A weight ratio of the urea to the calcium superphosphate (double superphosphate) to the potassium chloride (potassium sulfate) to the biochemical inhibitor to the carbon source (amino acid) is 1: (0.3-0.5): (0.8-1): (0.001-0.1): (0.1-0.3).

[0011] According to the above measure, the inhibitor is dissolved in an organic solvent and mechanically stirred and mixed uniformly by a stirring pump; the above measured carbon source (y-polyglutamic acid) is dissolved in a solution and mechanically stirred and mixed uniformly by the stirring pump; and the two mixed solutions and phosphorus and potassium fertilizers are added into urea urine pulp to be homogenized, and then granulated by a conventional urea granulation apparatus, thereby obtaining the carbon-coupled stabilized compound fertilizer with particle size of 0.85-2.8 mm accounting for more than 93%.

[0012] After a certain amount of carbon source y-polyglutamic acid is added into soil to achieve a C/N ratio of 25:1 in the soil, the nitrogen loss caused by the untimely supply of the carbon source can be alleviated. The carbon and nitrogen are fixed in the microorganisms simultaneously, decomposed by the microorganisms and fixed by clay minerals, and the nitrogen is released slowly, thereby meeting the growth demand of crops on compound fertilizer in different periods. The y-polyglutamic acid is a soluble, biodegradable and non-toxic biological polymer prepared by a microorganism fermentation method. The y-polyglutamic acid is a sticky substance, which is first found in fermented beans (natto). It is a special anionic natural polymer. The y-polyglutamic acid is formed by condensing D-type and L-type glutamic acid molecules through amide bonds between a-amino and y-carboxylic acid groups, with a molecular weight of 5000-10000 million Daltons and a structural formula shown in the following formula 1:

HO 0o- --

H H2 H2 li 0

Formula 1 Structural formula of polyglutamic acid

[0013] Polyglutamic acid is anew generation of plant nutrition enhancer and can act as an ion pump as a polymer compound, which can enhance the absorption of nitrogen, phosphorus, potassium and trace elements. The y-polyglutamic acid has bio-compatibility and complexity for positive and negative charges and can play a role of the pump, a carrier and a concentrator, which effectively locks nutrients, increases effective concentration of nutrients, reduces loss of chemical fertilizers, concentrates nutrients, increases the utilization rate of fertilizers, and promotes the root development of crops and the synthesis of proteins, thereby achieving an effect of increasing the yield and improving the quality. Meanwhile, the polyglutamic acid is a safe, environment-friendly and hormone-free product, which can be degraded into monomer amino-glutamate, can be absorbed by the crops, and is safe, efficient and pollution-free.

[0014] The disclosure has the following advantages:

[0015] 1. After the carbon-coupled compound fertilizer is applied, due to the addition of nitrification inhibitor, the compound fertilizer will remain in the soil in a form of ammonium nitrogen for a long time, thereby avoiding the emergence of nitrate nitrogen, reducing nitrogen loss caused by nitrogen leaching and denitrification, increasing the utilization rate of nitrogen fertilizer, promoting the existence of nitrogen fertilizer in a form of ammonium nitrogen, reducing the supply time of nitrate nitrogen and nitriate nitrogen, reducing the toxicity to the crops at a seedling stage and enhancing the disease and insect resistance.

[0016] 2. After the carbon-coupled stabilized compound fertilizer is applied, the demand of the crop growth on the carbon source can be met; and the added carbon source is y-polyglutamic acid, so that while the carbon source is supplemented, the y-polyglutamic acid also has an effect for activating the phosphorus nutrient, thereby meeting the demand of the crops on phosphorus.

[0017] 3. After the carbon-coupled compound fertilizer is applied, part of fertilizer is stored in the soil. Because the carbon-coupled stabilized compound fertilizer has both the carbon source and the nitrogen source, the nitrogen of the fertilizer is retained by the retention effect of the microorganisms on one hand and by the fixation effect of clay minerals on the other hand. The retention of the microorganisms is mainly reflected in that when the carbon source is sufficient, the microorganisms may absorb the carbon source and the nitrogen source at the same time to meet their own growth and development, so that the nitrogen is fixed in the soil in a form of organic nitrogen and released slowly when the crops need the nitrogen. The combination of the two enriches a nitrogen pool of the soil, which increases the nitrogen retention. The characteristics of the nitrogen pool in the soil are improved. On the other hand, because of the special molecular structure, the y-polyglutamic acid has strong moisture retention capacity, which can improve the soil aggregate structure, loosen the soil, and improve the water and fertilizer retention capacity of the soil. Moreover, the y-polyglutamic acid can regulate the acidity and alkalinity of the soil, reduce the content of heavy metals in the soil and can be made into multifunctional fertilizers containing sodium, calcium, magnesium, hydrogen, etc., thereby meeting the demand of crops on various nutrition elements.

[0018] 4. After the carbon-coupled stabilized compound fertilizer is applied, not only the soil nitrogen can be fixed, the utilization rate of nitrogen fertilizer can be increased, the emission of greenhouse gases can be reduced and environment pollution can be reduced, but also the release of phosphorus is facilitated, the potassium is activated, and the synergistic effect especially for the potassium fertilizer is obvious, so that effects for increasing roots, strengthening seedlings, resisting diseases, preventing falling, and increasing the yield and income can be achieved.

[0019] 5. After the carbon-coupled stabilized compound fertilizer is applied, since the components of the fertilizer have the characteristics of high stability and economical performance, and capability of transforming, absorbing and retaining nutrients such as nitrogen, etc., and can obviously absorb NH4 *, phosphate and other inorganic salt ions, the nitrogen loss in the soil can be reduced, the utilization efficiency of organic fertilizer can be increased effectively, and the fertility of the soil can be improved gradually. Meanwhile, because of a porous structure and large specific surface area, the application of the compound fertilizer to the soil may have direct or indirect impact on bulk density, water content, porosity, electrical conductivity, cationic exchange amount, nutrient conditions of the soil, etc., thereby affecting a micro environment of the soil.

[0020] 6. After the carbon-coupled stabilized compound fertilizer is applied, the biochemical inhibitor (the urease inhibitor and the nitrification inhibitor) are combined with the y-polyglutamic acid to prepare a compound synergist for fertilizer, so that the synergistic effect of the urease inhibitor and the nitrification inhibitor for inhibiting the hydrolysis and transformation of urea-state nitrogen can be played fully; the synergistic effect of the y-polyglutamic acid for improving the nutrient absorption and the water and fertilizer retention of the crops can effectively inhibit the hydrolysis of the urea and transformation to the nitrate nitrogen, so that the fertilizer longevity of the urea nitrogen fertilizer can be effectively prolonged, the absorption effect of the nitrogen by the crops can be improved, the absorption amount of nitrogen by the plants can be increased, the utilization rate of the fertilizer can be increased, the content of nutritional substances such as proteins, amino acid, fat and the like in agricultural products can be increased; and at the same time, the trace elements for the plants in the soil can be activated, the effective concentration of the trace elements for the crops in the soil can be increased, and the absorption of other nutrients by the crops can be promoted.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0021] The disclosure is further described in detail below in combination with embodiments.

[0022] Embodiment 1:

[0023] Components of a carbon-coupled stabilized compound fertilizer include urea, calcium superphosphate, potassium sulfate, urease inhibitor and polyglutamic acid.

[0024] Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of y-polyglutamic acid are added.

[0025] Preparation method:

[0026] Based on 100 parts (kg) of urea urine pulp (molten urea), 5 parts of ammonium thiosulfate are dissolved in 300-500 ml (400 ml here) of methanol with the volume concentration of 37% (serving as a carrier of a slow release agent) and mixed fully and uniformly; 20 parts of y-polyglutamic acid are dissolved in water and mixed uniformly; and calcium superphosphate is preheated by a flue gas concurrent flow direct heating method, so that the water content is reduced to less than 5%, an inlet temperature of flue gas is 400-500°C, and a material outlet temperature is generally 75-85°C. A measuring pump is used to calculate a flow rate. The above two mixed solutions, 50 parts of calcium superphosphate and 100 parts of potassium sulfate are added into the urea urine pulp, and granulated by an apparatus and process for producing conventional granular urea, thereby obtaining the carbon-coupled stabilized compound fertilizer with particle size of 0.85-2.8mm>90% and a nitrogen-phosphorus-potassium ratio of 24-12-24.

[0027] Embodiment 2:

[0028] Components of a carbon-coupled stabilized compound fertilizer include urea, double superphosphate, potassium chloride, urease inhibitor, nitrification inhibitor and y-polyglutamic acid.

[0029] Based on 100 parts (100 kg) of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, 300-500 ml (400 ml here) of methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid are added.

[0030] Preparation method:

[0031] Based on 100 parts of urea urine pulp (molten urea), 2.5 parts of ammonium thiosulfate and 2.5 parts of 3,4-dimethylpyrazole phosphate are dissolved in 300-500 ml (400 ml here) of methanol with the volume concentration of 37% (serving as a carrier of a slow release agent), and mixed fully and uniformly; 20 parts of y-polyglutamic acid are dissolved in water and mixed uniformly; and a measuring pump is used to calculate a flow rate, the above two mixed solutions, 50 parts of double superphosphate and 100 parts of potassium chloride are added into the urea urine pulp, and granulated by an apparatus and process for producing conventional granular urea, thereby obtaining the carbon-coupled stabilized compound fertilizer with particle size of 0.85-2.8mm>90% and a nitrogen-phosphorus-potassium mass ratio of 24: 12: 24.

[0032] Embodiment 3:

[0033] Components of a carbon-coupled stabilized compound fertilizer include urea, nitrification inhibitor, calcium superphosphate, potassium chloride and y-polyglutamic acid.

[0034] Based on 100 parts (100 kg) of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid are added.

[0035] Preparation method:

[0036] Based on 100 parts of urea urine pulp (molten urea), 5 parts of 3,4-dimethylpyrazole phosphate are dissolved in 300-500 ml (400 ml here) of methanol with the volume concentration of 37% (serving as a carrier of a slow release agent), and mixed fully and uniformly; 20 parts of polyglutamic acid are dissolved in water and mixed uniformly; and a measuring pump is used to calculate a flow rate, the above two mixed solutions, 50 parts of double superphosphate and 100 parts of potassium chloride are added into the urea urine pulp, and granulated by an apparatus and process for producing conventional granular urea, thereby obtaining the carbon-coupled stabilized compound fertilizer with particle size of 0.85-2.8mm>90% and a nitrogen-phosphorus-potassium ratio of 24-12-24.

[0037] Application example 1:

[0038] The field comparative experiment was carried out for the carbon-nitrogen-coupled fertilizer produced according to the embodiment I on corn, paddy rice and wheat. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). A control group was treated with conventional urea. The application amount of nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for corn land mass of the control group, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The application amount of nitrogen in the application example was 80% of the control group. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass, and on May 20 for the paddy rice planting land mass. Field experimental results were obtained as follows: Unit: Mu Conventional urea Carbon-coupled stabilized compound fertilizer Application (nitrogen content: 46.3%) (nitrogen content: 24%) crop Application of Yield kg Application of Yield kg Yield increase pure nitrogen kg pure nitrogen kg (%) Corn 12 947 12 962 2.0 Paddy rice 15 953 15 992 5.2 Wheat 5 354 4 362 5.2

[0039] Application comparative example 1:

[0040] The present application comparative example was a field application comparative experiment of a fertilizer without a carbon-containing material and the carbon-coupled stable fertilizer The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of the nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for corn land mass, 15 kg of pure nitrogen per Mu for the paddy rice and 5 kg of pure nitrogen per Mu for the wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass and on May 20 for the paddy rice planting land mass.

[0041] Afield comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 and a product without the carbon source (without polyglutamic acid). The crops planted were corn, paddy rice and wheat. Components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate and urease inhibitor ammonium thiosulfate. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate and 5 parts of ammonium thiosulfate were added.

[0042] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 and a product without the carbon source (without polyglutamic acid). The crops planted were corn, paddy rice and wheat. The components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added.

Components of a comparative example of the embodiment 2 included urea, calcium superphosphate, potassium sulfate, urease inhibitor and nitrification inhibitor. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of ammonium thiosulfate and 5 parts of 3,4-dimethylpyrazole phosphate were added.

[0043] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 and a product without a carbon source (without polyglutamic acid). The crops planted were corn, paddy rice and wheat. The components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 3 included urea, calcium superphosphate, potassium chloride and nitrification inhibitor. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate were added.

[0044] The experiment results showed that on the field crops such as corn, paddy rice and wheat, after the carbon-nitrogen-coupled compound fertilizer of the disclosure and the corresponding fertilizer product without the carbon source were applied, the crop yield decreased significantly. The mechanism was that after the carbon source was increased, more nitrogen, phosphorus and potassium were retained in the soil and released slowly in the later period of the development of crops for meeting the growth demand of the crops, thereby supporting the demand on the nitrogen, phosphorus and potassium nutrients in the later period of the nutrition growth and the reproductive growth period.

Field comparative experiment of carbon-nitrogen-coupled stabilized compound fertilizer and a fertilizer product without a carbon source

Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative produced of example of produced of example of produced of example of embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 920 989 941 984 922 Kg/Mu Yield of paddyrice 953 924 992 935 971 930 Kg/Mu Yield of wheat 354 322 399 340 365 342 Kg/Mu

[0045] Application comparative example 2:

[0046] Field comparative experiment when an addition amount of a carbon-containing material is greater than an upper limit of a protection scope. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of the nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for the corn land mass, 15 kg of pure nitrogen per Mu for paddy rice and 5 kg of pure nitrogen per Mu for wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass and on May 20 for the paddy rice planting land mass.

[0047] The field application effect of the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 was compared with that of a product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.05: 1. The components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate and urease inhibitor ammonium thiosulfate. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate and 100 parts of y-polyglutamic acid were added.

[0048] The field application effect of the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 was compared with that of a product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.05: 1, wherein 0.1 part of biochemical inhibitor included 0.05 part of urease inhibitor and 0.05 part of nitrification inhibitor. Components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and carbon source y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate and 100 parts of y-polyglutamic acid were added.

[0049] The field application effect of the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 was compared with that of a product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.05: 1. The components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate and 100 parts of y-polyglutamic acid were added.

[0050] At this time, the addition amount of the carbon source was beyond a protection scope. It was discovered that due to the increase of carbon, the demand of microorganisms on nitrogen was also increased a lot, thereby causing the competition of the microorganisms for the nitrogen in the soil, further influencing the absorption and utilization of the nitrogen by the crops, and reducing the crop yield.

Field comparative experiment of carbon-coupled stabilized compound fertilizer and a fertilizer product with an addition amount of carbon source greater than an upper limit of the protection scope Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative Application produced of example of produced of example of produced of example of crop embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 872 959 912 949 891 Kg/Mu Yield of paddyrice 953 899 947 893 969 902 Kg/Mu Yield of wheat 354 323 362 305 349 318 Kg/Mu

[0051] Application comparative example 3:

[0052] Field comparative experiment when an addition amount of the carbon-containing material is less than the protection scope. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for the corn land mass, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass, and on May 20 for the paddy rice planting land mass.

[0053] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 and a comparative product containing nitrogen fertilizer, phosphorus fertilizer, biochemical inhibitor and carbon source in a weight ratio of 1: 0.5: 1: 0.05: 0.01. The crops planted were corn, paddy rice and wheat. Components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp,

50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate and 1 part of y-polyglutamic acid were added.

[0054] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.05: 0.01. The crops planted were corn, paddy rice and wheat. 0.05 part of biochemical inhibitor contained 0.025 part of ammonium thiosulfate and 0.025 part of 3,4-dimethylpyrazole phosphate. The components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate and 1 part of y-polyglutamic acid were added. A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.05: 0.01. The crops planted were corn, paddy rice and wheat. Components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 3 included urea, nitrification inhibitor, calcium superphosphate, potassium chloride and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate and 1 part of y-polyglutamic acid were added.

[0055] The experimental results showed that on the field crops such as corn, paddy rice and wheat, after the carbon-nitrogen-coupled compound fertilizer of the disclosure and the corresponding fertilizer product with the addition amount of carbon source less than the lower limit of the protection scope were applied, the crop yield decreased significantly, which stated that the sufficient addition amount of the carbon source was a necessary condition for guaranteeing the crop yield.

Field comparative experiment of carbon-coupled stabilized compound fertilizer and a fertilizer product with an addition amount of carbon source less than a lower limit of the protection scope Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative produced of example of produced of example of produced of example of embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 913 989 942 984 930 Kg/Mu Yield of paddyrice 953 926 992 926 971 929 Kg/Mu Yield of wheat 354 322 399 342 365 334 Kg/Mu

[0056] Application comparative example 4:

[0057] Field comparative experiment when no inhibitor is added. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for the corn land mass, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on

April 15 for the wheat planting land mass, and on May 20 for the paddy rice planting land mass.

[0058] Afield comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of -polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate and 20 parts of y-polyglutamic acid were added.

[0059] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 2 included urea, double superphosphate, potassium chloride and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride and 20 parts of y-polyglutamic acid were added.

[0060] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 3 included urea, calcium superphosphate, potassium chloride and nitrification inhibitor. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride and 20 parts of y-polyglutamic acid were added.

[0061] The experiment results showed that on the field crops such as com, paddy rice and wheat, after the carbon-nitrogen-coupled nitrogen fertilizer of the disclosure and the corresponding product without the inhibitor were applied, it was discovered from the comparative experiment that the crop yield decreased, which stated that the advantage of the product lay in the effective cooperation of the carbon and nitrogen. When there is no inhibitor, the nitrogen cannot be effectively controlled, and the addition of the carbon source become meaningless.

Field comparative experiment of carbon-nitrogen-coupled stabilized compound fertilizer and a fertilizer product without inhibitor

Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative produced of example of produced of example of produced of example of embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 912 959 918 949 915 Kg/Mu _________________________________ Yield of paddy 953 910 947 902 969 911 rice Kg/Mu Yield of wheat 354 330 362 326 349 331 Kg/Mu

[0062] Application comparative example 5

[0063] Field comparative experiment when an addition amount of inhibitor is greater than an upper limit of a protection scope. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for the corn land mass, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass, and on May 20 for the paddy rice planting land mass.

[0064] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.2: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of -polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 20 parts of ammonium thiosulfate and 20 parts of y-polyglutamic acid were added.

[0065] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 and a comparative product containing nitrogen fertilizer, phosphorus fertilizer, biochemical inhibitor and carbon source in a weight ratio of 1: 0.5: 1: 0.2: 0.2. The crops planted were corn, paddy rice and wheat. 0.2 part of biochemical inhibitor contained 0.1 part of urease inhibitor ammonium thiosulfate and 0.1 part of nitrification inhibitor 3,4-dimethylpyrazole phosphate. Components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 10 parts of urease inhibitor ammonium thiosulfate, 10 parts of nitrification inhibitor 3,4-dimethylpyrazole phosphate and 20 part of y-polyglutamic acid were added.

[0066] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.2: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 20 parts of nitrification inhibitor 3,4-dimethylpyrazole phosphate and 20 parts of y-polyglutamic acid were added.

[0067] Under the condition that the addition amount of the inhibitor was not greater than an upper limit of the protection scope, the crop yield was not changed significantly, which stated that the addition amount of the inhibitor in the protection scope was the optimum addition amount. If the addition amount was beyond the protection scope, the production cost would be increased.

Field comparative experiment of carbon-nitrogen-coupled stabilized compound fertilizer and a fertilizer product with an addition amount of inhibitor greater than an upper limit of the protection scope

Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative produced of example of produced of example of produced of example of embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 940 959 957 949 954 Kg/Mu Yield of paddyrice 953 956 947 950 969 968 Kg/Mu Yield of 354 358 362 365 349 344 1wheatKg/Mu I _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ I___I___I_ __1__ _ 1

[0068] Application comparative example 6

[0069] Field comparative experiment when an addition amount of inhibitor is less than a lower limit of a protection scope. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application amount of nitrogen fertilizer was equivalent to 12 kg of pure nitrogen per Mu for the corn land mass, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass, and on May 20 for the paddy rice planting land mass.

[0070] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 1 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.0005: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of ammonium thiosulfate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 1 included urea, calcium superphosphate, potassium sulfate, urease inhibitor ammonium thiosulfate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 0.05 part of ammonium thiosulfate and 20 parts of y-polyglutamic acid were added.

[0071] Afield comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 2 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.0005: 0.2. The crops planted were corn, paddy rice and wheat. 0.0005 part of biochemical inhibitor contained 0.00025 part of urease inhibitor and 0.00025 part of nitrification inhibitor. Components of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts (100 kg) of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 2.5 parts of ammonium thiosulfate, 2.5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the ammonium thiosulfate and 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 2 included urea, double superphosphate, potassium chloride, urease inhibitor ammonium thiosulfate, nitrification inhibitor 3,4-dimethylpyrazole phosphate and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of double superphosphate, 100 parts of potassium chloride, 0.025 parts of urease inhibitor ammonium thiosulfate, 0.025 parts of nitrification inhibitor 3,4-dimethylpyrazole phosphate and 20 part of y-polyglutamic acid were added.

[0072] A field comparative experiment was carried out for the carbon-coupled stabilized compound fertilizer produced according to the embodiment 3 and a comparative product containing a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source in a weight ratio of 1: 0.5: 1: 0.0005: 0.2. The crops planted were corn, paddy rice and wheat. Components of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,4-dimethylpyrazole phosphate, methanol with a volume concentration of 37% capable of dissolving the 3,4-dimethylpyrazole phosphate, and 20 parts of y-polyglutamic acid were added. Components of a comparative example of the embodiment 3 included urea, calcium superphosphate, potassium chloride, nitrification inhibitor and y-polyglutamic acid. Based on 100 parts of urea urine pulp,

50 parts of calcium superphosphate, 100 parts of potassium chloride, 0.05 parts of nitrification inhibitor 3,4-dimethylpyrazole phosphate and 20 parts of y-polyglutamic acid were added.

[0073] Application comparative example 7

[0074] Materials other than the protection scope were selected in the present comparative example to have the field comparative experiment. The application amount was equivalent to 12 kg of pure nitrogen per Mu for corn, 15 kg of pure nitrogen per Mu for paddy rice, and 5 kg of pure nitrogen per Mu for wheat. The fertilizer was applied as a base fertilizer at one time before the seeding (corn and wheat) and transplanting (paddy rice). The application time of the fertilizer was on May 1 for the corn planting land mass, on April 15 for the wheat planting land mass and on May 20 for the paddy rice planting land mass.

[0075] The biochemical inhibitor were N-butyl thiophosphotriamine and 3,5-dimethylpyrazole, and the carbon-containing material was L-polyglutamic acid. N-butyl thiophosphotriamine and 3,5-dimethylpyrazole were classic urease inhibitor and nitrification inhibitor, which had already proved in a large number of field experiments to have good urease inhibition and nitrificaiton inhibition effect. In the present comparative example, N-butyl thiophosphotriamine and 3,5-dimethylpyrazole were combined with the carbon-containing material L-polyglutamic acid for application. The L-polyglutamic acid is an isomer of the carbon-containing material y-polyglutamic acid claimed in the present disclosure and is formed by condensing glutamate in different combination forms. It was discovered from the field experimental result of the present comparative example that when the carbon-containing material was changed to the L-polyglutamic acid, the retention amount of the nitrogen in the soil was reduced significantly, which was reflected on a ground portion, and the crop yield was also reduced significantly. In the present experiment, a comparative product of the embodiment 1 included 100 parts of urea, 50 parts of calcium superphosphate, 100 parts of potassium sulfate, 5 parts of N-butyl thiophosphotriamine and 20 parts of L-polyglutamic acid. A comparative product of the embodiment 2 included 100 parts of urea, 50 parts of double superphosphate, 100 parts of potassium chloride, 2.5 parts of N-butyl thiophosphotriamine, 2.5 parts of 3,5-dimethylpyrazole and 20 parts of L-polyglutamic acid. A comparative product of the embodiment 3 included 100 parts of urea, 50 parts of calcium superphosphate, 100 parts of potassium chloride, 5 parts of 3,5-dimethylpyrazole and 20 parts of L-polyglutamic acid. The results of comparative experiment 7 showed that after the substance other than the carbon-containing material of the disclosure was used, the given function could not be realized, and also showed that the key of the product described in the disclosure lay in the cooperation of the nitrogen source, the biochemical inhibitor and the carbon-containing material in the soil.

Field comparative experiment with carbon-containing material and biochemical inhibitor beyond the protection scope Fertilizer Comparative Fertilizer Comparative Fertilizer Comparative Application produced of example of produced of example of produced of example of crop embodiment embodiment embodiment embodiment embodiment embodiment 1 1 2 2 3 3 Yield of corn 947 882 959 905 949 911 Kg/Mu Yield of paddyrice 953 887 947 903 969 919 Kg/Mu Yield of 354 335 362 312 349 324 wheatKg/Mu _____________________________________

Claims

The claims defining the invention are as follows: 1. A carbon-coupled stabilized compound fertilizer, comprising components of a nitrogen fertilizer, a phosphorus fertilizer, a potassium fertilizer, biochemical inhibitor and a carbon source, wherein a weight ratio of the nitrogen fertilizer to the phosphorus fertilizer to the potassium fertilizer to the biochemical inhibitor to the carbon source material is 1: (0.3-0.5): (0.8-1): (0.001-0.1): (0.1-0.3) (preferably 1: (0.4-0.5): (0.9-1): (0.02-0.1): (0.15-0.25), and more preferably 1: 0.5: 1: 0.05: 0.2).
2. The carbon-coupled stabilized compound fertilizer according to claim 1, wherein the biochemical inhibitor comprises urease inhibitor and nitrification inhibitor, or the biochemical inhibitor is urease inhibitor, or the biochemical inhibitor is nitrification inhibitor; the urease inhibitor comprises one or more than one of N-butyl phosphorothioate triamine, hydroquinone, phosphoryl triamine, ammonium thiosulfate, P- benzoquinone, cyclohexyl phosphorothioate triamide, cyclohexyl phosphoramide, hexaamidocyclotriphosphazene,N-halo-2-imidazolidinoneandN-N-dihdo-2-imidazolidinone; and the nitrification inhibitor comprises one or more than one of cetylpyridinium chloride, dicyandiamide, 1-methylpyrazole-1-hydroxyamide, 3-methylpyrazole, ethylene urea, etridiazole, 4-aminotriazole, thiourea, acetylene, 2-ethynyl pyridine, sulfathiazole, amidinothiourea, 1-amidino-2-thiourea, 3,4-dimethylpyrazole phosphate, sodium thiosulfate, potassium azide, sodium azide, calcium carbide, 2, 5-chloroaniline, 3-acetanilide, toluene, carbon disulfide, phenylacetylene, 2-propyn-1-ol, ammoxidized lignin and phenethyl phosphonium diamide.
3. The carbon-coupled stabilized compound fertilizer according to claim 1, wherein the carbon source is one or more than one of polyglutamic acid, humic acid and fulvic acid; preferably y-polyglutamic acid; and the y-polyglutamic acid is formed by condensing D-type and L-type glutamic acid molecules through amide bonds between a-amino and y-carboxylic acid groups, with a molecular weight of 5000-10000 million Daltons and a structural formula shown in the following formula 1:

HO O

H

H2 | 13 0

formula 1 structural formula of polyglutamic acid
4. The carbon-coupled stabilized compound fertilizer according to claim 1, wherein the nitrogen fertilizer is urea; the compound fertilizer contains a certain amount of phosphorus fertilizer and potassium fertilizer; the phosphorus fertilizer is one or more than one of calcium superphosphate or double superphosphate; and the potassium fertilizer is one or more than one of potassium chloride or potassium sulfate.
5. A preparation method of the carbon-coupled stabilized compound fertilizer of any one of claims 1-4, comprising: dissolving the inhibitor in an organic solvent according to the above dosage, mechanically stirring and mixing uniformly through a stirring pump, dissolving a carbon-containing material y-polyglutamic acid in water, and mixing uniformly; and adding the mixed solution of the two substances, the phosphorus fertilizer and the potassium fertilizer into urea urine pulp, and then granulating through a conventional urea granulation apparatus, thereby obtaining the carbon-coupled stabilized compound fertilizer with particle size of 0.85-2.8 mm accounting for more than 93%.