CN100404475C - A special controlled-release compound fertilizer for double-cropping early rice and late rice and its preparation method - Google Patents

Abstract

The invention relates to a special controlled-release compound fertilizer for rice and a preparation method thereof. A special controlled-release compound fertilizer for double cropping early rice and late rice, characterized in that it is prepared from coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials The percentage by weight of each raw material is: coated urea 40: 29-35, coated urea S80: 6-10, ammonium phosphate: 8-12, coated potassium sulfate S80: 3-5, potassium sulfate: 14 -18. Coated magnesium sulfate S80: 5-7, Magnesium sulfate: 21-27. The invention can fertilize at one time, has reasonable matching, is suitable for double-cropping early rice and late rice, and reduces labor cost and working time.

Description

A special controlled-release compound fertilizer for double-cropping early rice and late rice and its preparation method

technical field

The invention relates to a special controlled-release compound fertilizer for rice and a preparation method thereof.

Background technique

Rice is the main food crop in my country, and fertilization is one of the important material basis for increasing rice production. Rice fertilizers are affected by external factors such as climate and soil. At the same time, the objective needs of rice varieties for nutrition must be considered. my country has a vast territory, complex soil and climate conditions, and there are many varieties of rice with different nutritional characteristics. Traditional rice fertilization is difficult to meet different soils due to the single variety of fertilizers and quick-acting effects. Under climate conditions, different rice varieties have different effects on fertilizers. Therefore, not only the frequency of fertilization is large and the dosage is large, but also because the fertilizers used have many quick-acting components and a large amount of loss, resulting in environmental pollution.

According to the development characteristics of early, middle and late rice, rice has different nutritional requirements. For example, the full growth period of early rice Honda is 80-90 days. Generally, seedlings are transplanted in late April and harvested in mid-July. Vegetative growth and reproductive growth are carried out alternately. Double-cropping early rice generally reaches the peak of tillering 15-20 days after transplanting, and absorbs tillering to the booting stage. Nitrogen, phosphorus, and potassium nutrients account for 80% of the total absorption, and 20% in the later period. The absorption ratio of nitrogen, phosphorus and potassium in various rice growth stages is roughly 1:0.5:0.8.

Traditional early rice not only uses a large amount of fertilizer, but also has high cost and heavy labor, and excessive application of inorganic fertilizers will cause soil compaction, fertilizer loss, environmental pollution, and rice quality decline and other adverse effects. At the same time, the large-scale use of single chemical fertilizers can easily lead to nutritional imbalance, easy lodging and low resistance of rice. Therefore, modern scientific nutrition management should meet the following conditions: first, one-time fertilization for nutritional regulation; second, a reasonable combination of N-P-K in the main nutrient elements and trace elements S and Mg; third, N, which is easy to lose in the soil The fourth is to vigorously improve the use effect of chemical fertilizers; the fifth is to use fertilizers with the function of land use and cultivation; the sixth is to save labor and effort, and it is convenient for manual and mechanized operation.

Contents of the invention

The object of the present invention is to provide a special controlled-release compound fertilizer for double-cropping early rice and late rice that can be fertilized at one time and can be matched reasonably, and a preparation method thereof.

In order to achieve the above object, the technical solution of the present invention is: a special controlled-release compound fertilizer for double cropping early rice and late rice, characterized in that it consists of coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, sulfuric acid Potassium, coated magnesium sulfate S80 and magnesium sulfate raw materials are prepared, and the weight percentages of each raw material are:

Coated urea 40: 29-35, Coated urea S80: 6-10, Ammonium phosphate: 8-12,

Coated potassium sulfate S80: 3-5, Potassium sulfate: 14-18, Coated magnesium sulfate S80: 5-7,

Magnesium Sulfate: 21-27.

Described coating urea 40 is made up of coating 40 and urea, and the percentage by weight that coating 40 accounts for coating urea 40 is 10-14, and coating 40 wraps urea; Coating 40 is made of clay mineral, biodegradable resin and The composition of the active agent, each component accounting for 40% by weight of the coating is: clay mineral: 54-60, biodegradable resin: 38-44, active agent: 2-4.

The coated urea S80 is composed of coating S80 and urea, the coating S80 accounts for 10-14% by weight of the coating S80, and the coating S80 wraps the urea.

The coating potassium sulfate S80 is composed of coating S80 and potassium sulfate, the coating S80 accounts for 10-14 weight percent of the coating potassium sulfate S80, and the coating S80 wraps potassium sulfate.

The coating magnesium sulfate S80 is composed of coating S80 and magnesium sulfate, the coating S80 accounts for 10-14 weight percent of the coating magnesium sulfate S80, and the coating S80 wraps the magnesium sulfate.

The coating S80 is composed of clay minerals, biodegradable resins, plant starch and active agents, and the percentages by weight of each component of the coating S80 are: clay minerals: 53-57, biodegradable resins: 36-40, Active agent: 0.8-2, vegetable starch 4-8.

The clay mineral is diatomaceous earth; the biodegradable resin is any one or a mixture of more than one of butylene succinate, polyvinyl alcohol, polyacrylic acid and its derivatives, one The above mixing is any ratio; the active agent is any one of alkylsulfonate, alkylbenzenesulfonate, alkylsulfate, alkylphenol polyoxyethylene ether or a mixture of more than one , when more than one is mixed, it is an arbitrary proportion; the vegetable starch is any one or a mixture of more than one of rice flour, wheat flour, and corn flour, and when more than one are mixed, it is an arbitrary proportion.

The above-mentioned preparation method of special controlled-release compound fertilizer for double cropping early rice and late rice is characterized in that it comprises the following steps:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 10-14, and the percentage by weight of urea in coating urea 40 is 86-90. Select coating 40 and urea; prepare coating 40: according to the percentage by weight of coating 40 of each component: clay mineral: 54 -60, biodegradable resin: 38-44, activator: 2-4 select clay mineral, biodegradable resin and activator; Biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight and account for 1/ In the mixed solution of 2, select the mixed solution according to the weight ratio of clay mineral, biodegradable resin and active agent: mixed solution = 6-12: 90, add clay mineral, active agent and heat to 90-110 ° C, use a two-fluid nozzle At an air atomization pressure of 4KPa, spray on urea granules at a rate of 2kg per minute, dry, and screen to obtain coated urea 40 with a diameter of 3-4mm;

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). The percentage by weight of the coating urea S80 is 10-14, and the percentage by weight of the coating urea S80 accounted for by urea is 86-90 and the coating 580 and urea are selected; the coating 580 is prepared: the coating 580 percentage by weight of each component is: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 select clay mineral, biodegradable resin, plant starch and active agent; dissolve biodegradable resin in tetrachloromethane In the mixed solution that accounts for 1/2 of the weight of tetrachloroethane, clay mineral, biodegradable resin, plant starch and active agent: the weight ratio of mixed solution=6-12:90 is selected mixed solution, adds clay mineral, The active agent and vegetable starch are heated to 90-110°C, sprayed on the urea granules at a rate of 2kg per minute with a two-fluid nozzle at an air atomization pressure of 4KPa, dried and screened to obtain coated urea with a diameter of 3-4mm S80;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 10-14, and the percentage by weight of potassium sulfate S80 of coating potassium sulfate S80 is 86-90 to select coating S80 and Potassium sulfate; preparation of coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 selection Clay minerals, biodegradable resins, plant starch and active agents; the biodegradable resins are dissolved in a mixed solution of 1/2 the weight of tetrachloromethane and tetrachloroethane, according to clay minerals, biodegradable resins, plants Starch and activating agent: the weight ratio of mixed solution=6-12: 90 choose mixed solution, add clay mineral, activating agent and plant starch and heat to 90-110 ℃, be 4KPa in air atomizing pressure with two-fluid nozzle, with every The rate of 2kg per minute is sprayed onto potassium sulfate granules, dried and screened to obtain coated potassium sulfate S80 with a diameter of 3-4mm;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating 580 is 10-14, and the percentage by weight of magnesium sulfate accounted for coating magnesium sulfate 580 is 86-90 to select coating S80 and Magnesium sulfate; preparation of coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 selection Clay minerals, biodegradable resins, plant starch and active agents; the biodegradable resins are dissolved in a mixed solution of 1/2 the weight of tetrachloromethane and tetrachloroethane, according to clay minerals, biodegradable resins, plants Starch and activating agent: the weight ratio of mixed solution=6-12: 90 choose mixed solution, add clay mineral, activating agent and plant starch and heat to 90-110 ℃, be 4KPa in air atomizing pressure with two-fluid nozzle, with every The rate of 2kg per minute is sprayed onto magnesium sulfate particles, dried and screened to obtain coated magnesium sulfate S80 with a diameter of 3-4mm;

5). According to the percentage by weight of each raw material: coated urea 40: 29-35, coated urea S80: 6-10, ammonium phosphate: 8-12, coated potassium sulfate S80: 3-5, potassium sulfate: 14-18, coated magnesium sulfate S80: 5-7, magnesium sulfate: 21-27 select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and sulfuric acid Magnesium raw materials are mixed to obtain products.

The release of coated urea 40 was linear, and the release of N reached 80% at 40 days, mainly to meet the nitrogen requirements before the early greening fertilizer of rice and the mid-term tillering fertilizer. The release of coated urea S80 is non-linear, and the nutrient release is slow in the early stage of rice, mainly to meet the nitrogen needs of tillering fertilizer in the middle stage of rice and heading and fruiting fertilizer in the later stage.

The release of coated potassium sulfate S80 is non-linear, and the release of K is slow in the early stage, mainly to meet the tillering fertilizer in the middle stage of rice and the heading and fruiting fertilizer in the later stage. Potassium sulfate fertilizer is mainly to meet the potassium needs before the greening fertilizer in the early stage of rice and the tillering fertilizer in the middle stage.

The release of coated magnesium sulfate S80 is non-linear, and the release of Mg is slow in the early stage, mainly to meet the tillering fertilizer in the middle stage of rice and the heading and fruiting fertilizer in the later stage. The magnesium sulfate fertilizer is mainly to meet the magnesium requirements before the greening fertilizer in the early stage of rice and the tillering fertilizer in the middle stage.

Nitrogen, phosphorus, and potassium in fertilizers are a large number of elements, which are necessary for the development of rice, while magnesium and sulfur fertilizers can increase the photosynthetic efficiency of rice, increase the yield of rice, and improve the quality of rice.

According to the rice growth cycle and the difference in required nutrients, the present invention is greening fertilizer in the early stage, tillering fertilizer in the middle stage, and heading and fruiting fertilizer in the later stage. The greening fertilizer in the early stage is mainly completed by coating urea 40 (also known as controlled-release nitrogen fertilizer), ammonium phosphate, potassium sulfate and magnesium sulfate. S80 and coated magnesium sulfate S80 to complete. Mg and S fertilizers are beneficial to increase seed setting rate and improve rice quality.

The invention solves the problems of poor utilization effect, heavy environmental pollution and NPK ratio imbalance in the use of traditional chemical fertilizers. The components N, K, Mg and S of the invention are controllable, and the combination of N, P, K, Mg and S is reasonable. High content of Mg and S, suitable for double-cropping early rice and late rice. Implement the one-time fertilization method. The one-time fertilization season is in late April in the early rice transplanting period, June 20 in the single-season late rice transplanting period, and July 20 in the late rice transplanting period. Under the seedlings. The coating 40 and coating S80 used in the present invention are completely degradable.

The beneficial effects of the present invention are as follows: one is to change the multi-year fertilization of rice into one-time one-year fertilization, which reduces labor costs and operation time; second, it reduces the serious problem of water and fertilizer loss caused by multiple fertilization; According to the characteristics of the annual demand of rice crops for N and K fertilizers, the timely and reasonable regulation of N and K fertilizers is carried out, in line with the rules for the absorption of N and K nutrients at the booting stage of rice, and the purpose of scientific fertilization is achieved; four. It is a reasonable combination of N, P, K and Mg, S content, which is conducive to improving the light and performance of crops, and improving rice quality and resistance.

Instructions:

Early rice can use 9-10 kg of active N element per mu, double-season late rice can use 10 kg of N active ingredient per mu, and single-crop late rice can use the standard of 12 kg of N active ingredient per mu to convert the required amount of land per unit area. The amount of fertilization of the above-mentioned fertilizers. Then it is sprinkled into the field as a one-time base fertilizer after the rice is transplanted by a seeder or manually.

Detailed ways

In order to better understand the present invention, the content of the present invention is further illustrated below in conjunction with the examples, but the content of the present invention is not limited to the following examples.

Example 1:

A preparation method for special controlled-release compound fertilizer for double-cropping early rice and late rice, comprising the steps of:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 12, and the percentage by weight of urea in coating urea 40 is 88. Select coating 40 and urea; prepare coating 40: account for coating 40 weight percentage by each component: clay mineral: 58, biodegradable Resin: 39, active agent: 3 Select clay mineral, biodegradable resin and active agent; Dissolve biodegradable resin in tetrachloromethane and tetrachloroethane in the mixed solution that accounts for 1/2 weight each, mixed solution presses clay Minerals, biodegradable resin and active agent: the weight ratio of the mixed solution=8:90 is selected, add clay minerals, active agent is heated to 90-110 ℃, is 4KPa in the air atomization pressure with two-fluid nozzle, with 2kg per minute The progress is sprayed on the urea granules, dried and screened to obtain coated urea 40 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, and the biodegradable resin is butylene succinate, The active agent is an alkylsulfonate (such as: sodium dodecylsulfonate, etc., the same below);

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of coating urea S80 is 12, and the percentage by weight of coating urea S80 that urea accounts for is 88 and selects coating S80 and urea; Preparation coating S80: according to the percentage by weight of coating S80 that each component accounts for: clay mineral: 55, biodegradable Degradable resin: 38, active agent: 1, plant starch 6 select clay minerals, biodegradable resin, plant starch and active agent; dissolve the biodegradable resin in tetrachloromethane and tetrachloroethane, each accounting for 1/2 of the weight In the mixed solution, the mixed solution is selected according to the weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution = 8:90, and the clay mineral, active agent and plant starch are added and heated to 90-110° C. The fluid nozzle is sprayed onto the urea granules at an air atomization pressure of 4KPa at a rate of 2kg per minute, dried and screened to obtain coated urea S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, and the The biodegradable resin is butylene succinate, the active agent is alkylsulfonate, and the plant starch is rice flour;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). According to the percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 12, the percentage by weight of potassium sulfate accounted for coating potassium sulfate S80 is 88 to select coating S80 and potassium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 55, biodegradable resin: 38, active agent: 1, plant starch 6 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =8:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110 ° C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on potassium sulfate particles at a rate of 2 kg per minute, dry, and screen , to obtain coating potassium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is butylene succinate, and the active agent is alkylsulfonic acid Salt, the vegetable starch is rice flour;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating S80 is 12, and the percentage by weight of magnesium sulfate accounting for coating magnesium sulfate S80 is 88 to select coating S80 and magnesium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 55, biodegradable resin: 38, active agent: 1, plant starch 6 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =8:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the magnesium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated magnesium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is butylene succinate, and the active agent is alkylsulfonic acid Salt, the vegetable starch is rice flour;

5), for the ammonium phosphate purchased on the market, if it is a granular body, it needs to pass through screening, and its diameter is 3-4mm; it is used to prepare its matching raw materials (potassium sulfate, magnesium sulfate), if it is not a granular body, it must be granulated in advance. Screening and granulation methods can be roller or extrusion, to a diameter of 3-4mm;

6), select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials to mix according to Table 1 to obtain a product.

Table 1

raw material name Raw material composition (mass percentage) N-P₂O₅-K₂O-MgO-B Mixing ratio (percentage by weight) Guaranteed composition 18-4-9-3.0(Mg)-7.0(S)(mass percentage)N-P₂O₅-K₂O --MgO-S Coated urea 40 40.0-0.0-0.0 32.0 13.44-0.0-0.0-0.0-0.0 Coated urea 40.0-0.0-0.0 8.0 3.36-0.0-0.0-0.0-0.0

S80 ammonium phosphate 18.0-46.0-0.0-0.0-14.0 10.0 1.8-4.6-0.0-0.0-0.0 Coating potassium sulfate S80 0.0-0.0-45.0-0.0-16.2 4.0 0.0-0.0-1.8-0.0-0.648 Potassium sulfate 0.0-0.0-50.0-0.0-18.0 16.0 0.0-0.0-8.0-0.0-2.88 Coated Magnesium Sulfate S80 0.0-0.0-0.0-8.73-11.7 6.0 0.0-0.0-0.0-0.5238-0.702 Magnesium Sulfate 0.0-0.0-0.0-9.7-13.0 24.0 0.0-0.0-0.0-2.328-3.12 Total 100.0 18.6-4.6-9.8-2.85-7.35 Guaranteed ingredients 18.6-4.6-9.8-2.85-7.35

Example 2:

A preparation method for special controlled-release compound fertilizer for double-cropping early rice and late rice, comprising the steps of:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 12, and the percentage by weight of urea in coating urea 40 is 88. Select coating 40 and urea; prepare coating 40: account for coating 40 weight percentage by each component: clay mineral: 58, biodegradable Resin: 39, active agent: 3 Select clay mineral, biodegradable resin and active agent; Dissolve biodegradable resin in tetrachloromethane and tetrachloroethane in the mixed solution that accounts for 1/2 weight each, mixed solution presses clay Minerals, biodegradable resin and active agent: the weight ratio of the mixed solution=9:90 is selected, add clay minerals, active agent is heated to 90-110 ℃, is 4KPa in the air atomization pressure with two-fluid nozzle, with 2kg per minute The process is sprayed onto urea granules, dried and screened to obtain coated urea 40 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is polyvinyl alcohol, and the active The agent is alkylbenzenesulfonate (sodium alkylbenzenesulfonate, such as: sodium p-toluenesulfonate, the same below);

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of coating urea S80 is 12, and the percentage by weight of coating urea S80 that urea accounts for is 88 and selects coating S80 and urea; Preparation coating S80: according to the percentage by weight of coating S80 that each component accounts for: clay mineral: 55, biodegradable Degradable resin: 38, active agent: 1, plant starch 6 select clay minerals, biodegradable resin, plant starch and active agent; dissolve the biodegradable resin in tetrachloromethane and tetrachloroethane, each accounting for 1/2 of the weight In the mixed solution, the mixed solution is selected according to the weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution = 9:90, and the clay mineral, active agent and plant starch are added and heated to 90-110° C. The fluid nozzle is sprayed onto the urea granules at an air atomization pressure of 4KPa at a rate of 2kg per minute, dried and screened to obtain coated urea S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, and the The biodegradable resin is polyvinyl alcohol, the active agent is alkylbenzenesulfonate, and the vegetable starch is wheat flour;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). According to the percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 12, the percentage by weight of potassium sulfate accounted for coating potassium sulfate S80 is 88 to select coating S80 and potassium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 55, biodegradable resin: 38, active agent: 1, plant starch 6 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =9:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the potassium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coating potassium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is polyvinyl alcohol, and the active agent is an alkylbenzene sulfonate. Described vegetable starch is wheat flour;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating S80 is 12, and the percentage by weight of magnesium sulfate accounting for coating magnesium sulfate S80 is 88 to select coating S80 and magnesium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 55, biodegradable resin: 38, active agent: 1, plant starch 6 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =9:90 selection, add clay minerals, active agent and plant starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the magnesium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated magnesium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is polyvinyl alcohol, and the active agent is an alkylbenzene sulfonate. Described vegetable starch is wheat flour;

5), for the ammonium phosphate purchased on the market, if it is a granular body, it needs to pass through screening, and its diameter is 3-4mm; it is used to prepare its matching raw materials (potassium sulfate, magnesium sulfate), if it is not a granular body, it must be granulated in advance. Screening and granulation methods can be roller or extrusion, to a diameter of 3-4mm;

6). According to the weight percentage of each raw material: coated urea 40: 33, coated urea S80: 8, ammonium phosphate: 10, coated potassium sulfate S80: 4, potassium sulfate: 16, coated magnesium sulfate S80: 6. Magnesium sulfate: 23 selected coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials mixed to obtain the product.

Example 3:

A preparation method for special controlled-release compound fertilizer for double-cropping early rice and late rice, comprising the steps of:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 10, and the percentage by weight of the coating urea 40 accounted for by urea is 90 and the coating 40 and urea are selected; the coating 40 is prepared: the percentage by weight of each component of the coating 40 is: clay mineral: 54, biodegradable Resin: 42, active agent: 4 select clay mineral, biodegradable resin and active agent; dissolve biodegradable resin in tetrachloromethane and tetrachloroethane in the mixed solution that accounts for 1/2 weight each, mixed solution presses clay Minerals, biodegradable resins and active agents: the weight ratio of the mixed solution=6:90 is selected, add clay minerals, active agents are heated to 90-110 ° C, and the air atomization pressure is 4KPa with a two-fluid nozzle, at 2kg per minute The progress of spraying on the urea granules, drying, screening, to obtain a diameter of 3-4mm coated urea 40;

The clay mineral is diatomaceous earth, the biodegradable resin is polyacrylic acid, and the active agent is alkyl sulfate (such as: sodium lauryl sulfate, etc., the same below);

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of urea is 10, and the percentage by weight of coating urea S80 that urea accounts for is 90 and selects coating S80 and urea; Preparation coating S80: according to the percentage by weight of coating S80 that each component accounts for: clay mineral: 53, biodegradable Degradable resin: 37, active agent: 2, plant starch 8 select clay mineral, biodegradable resin, plant starch and active agent; dissolve biodegradable resin in tetrachloromethane and tetrachloroethane and account for 1/2 of the weight In the mixed solution, the mixed solution is selected according to the weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution=6:90, and the clay mineral, active agent and plant starch are added and heated to 90-110°C, The fluid nozzle is sprayed onto the urea granules at an air atomization pressure of 4KPa at a rate of 2kg per minute, dried and screened to obtain coated urea S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, and the The biodegradable resin is polyacrylic acid, the active agent is alkyl sulfate, and the vegetable starch is corn flour;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of the coating potassium sulfate S80 accounted for by the coating S80 is 10, and the percentage by weight of the coating potassium sulfate S80 accounted for by the coating S80 is 90 to select coating S80 and potassium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53, biodegradable resin: 37, active agent: 2, plant starch 8 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =6:90 selection, add clay minerals, active agent and plant starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the potassium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coating potassium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is polyacrylic acid, the active agent is an alkyl sulfate, and the plant Starch is corn flour;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating S80 is 10, and the percentage by weight of magnesium sulfate accounting for coating magnesium sulfate S80 is 90 to select coating S80 and magnesium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53, biodegradable resin: 37, active agent: 2, plant starch 8 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =6:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the magnesium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated magnesium sulfate S80 with a diameter of 3-4mm; the clay mineral is diatomaceous earth, the biodegradable resin is polyacrylic acid, the active agent is an alkyl sulfate, and the plant Starch is corn flour;

5). According to the weight percentage of each raw material: coated urea 40: 29, coated urea S80: 10, ammonium phosphate: 12, coated potassium sulfate S80: 3, potassium sulfate: 14, coated magnesium sulfate S80: 5. Magnesium sulfate: 27 select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials to mix the product.

Example 4:

A preparation method for special controlled-release compound fertilizer for double-cropping early rice and late rice, comprising the steps of:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 14, and the percentage by weight of urea in coating urea 40 is 86. Select coating 40 and urea; prepare coating 40: account for coating 40 weight percentage by each component: clay mineral: 60, biodegradable Resin: 38, activator: 2 Select clay mineral, biodegradable resin and activator; Dissolve biodegradable resin in tetrachloromethane and tetrachloroethane in the mixed solution that accounts for 1/2 weight each, mixed solution presses clay Minerals, biodegradable resin and active agent: the weight ratio of mixed solution=12:90 is selected, add clay mineral, active agent is heated to 90-110 ℃, is 4KPa in the air atomization pressure with two-fluid nozzle, with 2kg per minute The progress of spraying on the urea granules, drying, screening, to obtain a diameter of 3-4mm coated urea 40;

The clay mineral is diatomite, the biodegradable resin is butylene succinate and polyvinyl alcohol, and the weight of butylene succinate and polyvinyl alcohol each accounts for 1/2; Described active agent is alkyl sulfate (as: sodium lauryl sulfate) and alkylphenol polyoxyethylene ether, and the weight of alkyl sulfate and alkylphenol polyoxyethylene ether respectively accounts for 1/2;

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of coating urea S80 is 14, and the percentage by weight of coating urea S80 that urea accounts for is 86 and selects coating S80 and urea; Preparation coating S80: according to the percentage by weight of coating S80 that each component accounts for: clay mineral: 57, biodegradable Degradable resin: 38.2, active agent: 0.8, plant starch 4 select clay minerals, biodegradable resin, plant starch and active agent; dissolve the biodegradable resin in tetrachloromethane and tetrachloroethane and account for 1/2 of the weight In the mixed solution, the mixed solution is selected according to the weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution = 12:90, and the clay mineral, active agent and plant starch are added and heated to 90-110° C. The fluid nozzle is sprayed on the urea granules at an air atomization pressure of 4KPa at a rate of 2kg per minute, dried and screened to obtain coated urea S80 with a diameter of 3-4mm;

The clay mineral is diatomite, the biodegradable resin is butylene succinate and polyvinyl alcohol, and the weight of butylene succinate and polyvinyl alcohol each accounts for 1/2; Described active agent is alkyl sulfate and alkylphenol polyoxyethylene ether, and the weight of alkyl sulfate and alkylphenol polyoxyethylene ether respectively accounts for 1/2; Described plant starch is rice flour and wheat flour, and rice flour and 1/2 of the weight of wheat flour;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 14, and the percentage by weight of potassium sulfate S80 of coating potassium sulfate S80 is 86 to select coating S80 and potassium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 57, biodegradable resin: 38.2, active agent: 0.8, plant starch 4 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =12:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110 ° C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on potassium sulfate particles at a rate of 2 kg per minute, dry, and screen , to obtain coated potassium sulfate S80 with a diameter of 3-4mm;

The clay mineral is diatomite, the biodegradable resin is butylene succinate and polyvinyl alcohol, and the weight of butylene succinate and polyvinyl alcohol each accounts for 1/2; Described active agent is alkyl sulfate and alkylphenol polyoxyethylene ether, and the weight of alkyl sulfate and alkylphenol polyoxyethylene ether respectively accounts for 1/2; Described plant starch is rice flour and wheat flour, and rice flour and 1/2 of the weight of wheat flour;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). According to the percentage by weight of coating magnesium sulfate S80 accounted for by coating S80, it is 14, and the percentage by weight of magnesium sulfate accounting for coating magnesium sulfate S80 is 86 to select coating S80 and magnesium sulfate; prepare Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 57, biodegradable resin: 38.2, active agent: 0.8, plant starch 4 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =12:90 selection, add clay minerals, active agent and plant starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the magnesium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated magnesium sulfate S80 with a diameter of 3-4mm;

The clay mineral is diatomite, the biodegradable resin is butylene succinate and polyvinyl alcohol, and the weight of butylene succinate and polyvinyl alcohol each accounts for 1/2; Described active agent is alkyl sulfate and alkylphenol polyoxyethylene ether, and the weight of alkyl sulfate and alkylphenol polyoxyethylene ether respectively accounts for 1/2; Described plant starch is rice flour and wheat flour, and rice flour and 1/2 of the weight of wheat flour;

5). According to the weight percentage of each raw material: coated urea 40:35, coated urea S80: 6, ammonium phosphate: 8, coated potassium sulfate S80: 5, potassium sulfate: 18, coated magnesium sulfate S80: 7. Magnesium sulfate: 21 select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials to obtain the product.

Example 5:

A preparation method for special controlled-release compound fertilizer for double-cropping early rice and late rice, comprising the steps of:

1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 13, and the percentage by weight of urea in coating urea 40 is 87. Select coating 40 and urea; prepare coating 40: account for coating 40 weight percentage by each component: clay mineral: 54, biodegradable Resin: 44, activator: 2 Select clay mineral, biodegradable resin and activator; Dissolve biodegradable resin in tetrachloromethane and tetrachloroethane in the mixed solution that accounts for 1/2 weight respectively, and mixed solution presses clay Minerals, biodegradable resin and active agent: the weight ratio of the mixed solution=10:90 is selected, add clay minerals, active agent is heated to 90-110 ℃, is 4KPa in the air atomization pressure with two-fluid nozzle, with 2kg per minute The progress of spraying on the urea granules, drying, screening, to obtain a diameter of 3-4mm coated urea 40;

Described clay mineral is diatomite; Described biodegradable resin is polyacrylic acid and polyacrylic acid derivative (polyacrylic acid isooctyl, hereinafter the same), and the weight of polyacrylic acid and polyacrylic acid derivative each accounts for 1/2 ; The active agent is an alkyl sulfonate and an alkylbenzene sulfonate, and the weight of the alkyl sulfonate and the alkylbenzene sulfonate each accounts for 1/2;

2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of coating urea S80 is 13, and the percentage by weight of coating urea S80 that urea accounts for is 87 to select coating S80 and urea; Preparation coating S80: according to the weight percentage of coating S80 that each component accounts for: clay mineral: 53, bioavailable Degradable resin: 40, active agent: 2, plant starch 5 select clay minerals, biodegradable resin, plant starch and active agent; dissolve the biodegradable resin in tetrachloromethane and tetrachloroethane and account for 1/2 of the weight In the mixed solution, the mixed solution is selected according to the weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution=10:90, and the clay mineral, active agent and plant starch are added and heated to 90-110°C, The fluid nozzle is sprayed on the urea granules at an air atomization pressure of 4KPa at a rate of 2kg per minute, dried and screened to obtain coated urea S80 with a diameter of 3-4mm;

The clay mineral is diatomaceous earth; the biodegradable resin is polyacrylic acid and polyacrylic acid derivatives (isooctyl polyacrylate), and the weight of polyacrylic acid and polyacrylic acid derivatives each accounts for 1/2; The active agent is alkyl sulfonate and alkylbenzene sulfonate, and the weight of alkyl sulfonate and alkylbenzene sulfonate respectively accounts for 1/2; Described plant starch is wheat flour and corn flour, and wheat flour and The weight of corn flour accounts for 1/2 each;

3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 13, and the percentage by weight of potassium sulfate S80 of coating potassium sulfate S80 is 87 to select coating S80 and potassium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53, biodegradable resin: 40, active agent: 2, plant starch 5 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight each accounted for 1/2 in the mixed solution, mixed solution by clay minerals, biodegradable resin, plant starch and active agent: the weight ratio of mixed solution =10:90 selection, add clay minerals, active agent and plant starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the potassium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated potassium sulfate S80 with a diameter of 3-4mm;

The clay mineral is diatomite; the biodegradable resin is polyacrylic acid and polyacrylic acid derivatives, and the weight of polyacrylic acid and polyacrylic acid derivatives each accounts for 1/2; the active agent is alkyl sulfonate salt and alkylbenzenesulfonate, the weight of alkylsulfonate and alkylbenzenesulfonate each accounts for 1/2; the plant starch is wheat flour and corn flour, and the weight of wheat flour and corn flour respectively accounts for 1 /2;

4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating S80 is 13, and the percentage by weight of magnesium sulfate accounting for coating magnesium sulfate S80 is 87 to select coating S80 and magnesium sulfate; preparation Coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53, biodegradable resin: 40, active agent: 2, plant starch 5 select clay mineral, biodegradable resin, plant starch and active agent; the biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight in the mixed solution of 1/2, the mixed solution is by weight ratio of clay mineral, biodegradable resin, plant starch and active agent: mixed solution =10:90 selection, add clay minerals, active agent and vegetable starch and heat to 90-110°C, use a two-fluid nozzle at an air atomization pressure of 4KPa, spray on the magnesium sulfate granules at a rate of 2kg per minute, dry, and screen , to obtain coated magnesium sulfate S80 with a diameter of 3-4mm;

The clay mineral is diatomite; the biodegradable resin is polyacrylic acid and polyacrylic acid derivatives, and the weight of polyacrylic acid and polyacrylic acid derivatives each accounts for 1/2; the active agent is alkyl sulfonate salt and alkylbenzenesulfonate, the weight of alkylsulfonate and alkylbenzenesulfonate each accounts for 1/2; the plant starch is wheat flour and corn flour, and the weight of wheat flour and corn flour respectively accounts for 1 /2;

5). According to the weight percentage of each raw material: coated urea 40:35, coated urea S80: 6, ammonium phosphate: 8, coated potassium sulfate S80: 5, potassium sulfate: 18, coated magnesium sulfate S80: 7. Magnesium sulfate: 21 select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate raw materials to obtain the product.

Claims (2)

1. a special controlled-release compound fertilizer for double-season early rice and late rice, characterized in that it consists of coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and magnesium sulfate Raw materials are prepared, and the weight percentages of each raw material are: Coated urea 40: 29-35, Coated urea S80: 6-10, Ammonium phosphate: 8-12, Coated potassium sulfate S80: 3-5, Potassium sulfate: 14-18, Coated magnesium sulfate S80: 5-7, Magnesium sulfate: 21-27; Described coating urea 40 is made up of coating 40 and urea, and the percentage by weight that coating 40 accounts for coating urea 40 is 10-14, and coating 40 wraps urea; Coating 40 is made of clay mineral, biodegradable resin and Active agent composition, each component accounts for 40% by weight of the coating: clay mineral: 54-60, biodegradable resin: 38-44, active agent: 2-4; The clay mineral described in the coating 40 is diatomaceous earth; the biodegradable resin is any one or a mixture of more than one of butylene succinate, polyvinyl alcohol, polyacrylic acid and its derivatives , when more than one is mixed, it is any ratio; the active agent is any one or one of alkylsulfonate, alkylbenzenesulfonate, alkylsulfate, alkylphenol polyoxyethylene ether For the above mixtures, when more than one is mixed, the ratio is arbitrary; The coated urea S80 is composed of coating S80 and urea, the coating S80 accounts for 10-14% by weight of the coating S80, and the coating S80 wraps the urea; The coating potassium sulfate S80 is composed of coating S80 and potassium sulfate, the coating S80 accounts for 10-14% by weight of the coating potassium sulfate S80, and the coating S80 wraps potassium sulfate; The coating magnesium sulfate S80 is composed of coating S80 and magnesium sulfate, and the coating S80 accounts for 10-14 weight percent of the coating magnesium sulfate S80, and the coating S80 wraps magnesium sulfate; The coating S80 is composed of clay minerals, biodegradable resins, plant starch and active agents, and the percentages by weight of each component of the coating S80 are: clay minerals: 53-57, biodegradable resins: 36-40, Active agent: 0.8-2, plant starch 4-8; The clay mineral described in coating S80 is diatomaceous earth; the biodegradable resin is any one or a mixture of more than one of butylene succinate, polyvinyl alcohol, polyacrylic acid and its derivatives , when more than one is mixed, it is any ratio; the active agent is any one or one of alkylsulfonate, alkylbenzenesulfonate, alkylsulfate, alkylphenol polyoxyethylene ether For the above mixtures, when more than one are mixed, the ratio is arbitrary; when the vegetable starch is any one or more than one of rice flour, wheat flour, and corn flour, the ratio is arbitrary when more than one are mixed. 2. a kind of double crop early rice as claimed in claim 1 and the preparation method of special controlled-release compound fertilizer for late rice are characterized in that it comprises the steps: 1). Prepare coated urea 40: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; The percentage by weight is 10-14, and the percentage by weight of urea in coating urea 40 is 86-90. Select coating 40 and urea; prepare coating 40: according to the percentage by weight of coating 40 of each component: clay mineral: 54 -60, biodegradable resin: 38-44, activator: 2-4 select clay mineral, biodegradable resin and activator; Biodegradable resin is dissolved in tetrachloromethane and tetrachloroethane weight and account for 1/ In the mixed solution of 2, select the mixed solution according to the weight ratio of clay mineral, biodegradable resin and active agent: mixed solution = 6-12: 90, add clay mineral, active agent and heat to 90-110 ° C, use a two-fluid nozzle At an air atomization pressure of 4KPa, spray on urea granules at a rate of 2kg per minute, dry, and screen to obtain coated urea 40 with a diameter of 3-4mm; 2). Preparation of coated urea S80: (a) select granular urea with a diameter of 3-4mm, put it into a fluidized bed, and heat it to 60-80°C; (b). Coat urea S80 according to the proportion of coating S80 The percentage by weight of coating urea S80 is 10-14, and the percentage by weight of coating urea S80 that urea accounts for is 86-90 to select coating S80 and urea; Prepare coating S80: according to the percentage by weight of coating S80 that each component accounts for: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 select clay mineral, biodegradable resin, plant starch and active agent; dissolve biodegradable resin in tetrachloromethane In the mixed solution that accounts for 1/2 of the weight of tetrachloroethane, clay mineral, biodegradable resin, plant starch and active agent: the weight ratio of mixed solution=6-12:90 is selected mixed solution, adds clay mineral, The active agent and vegetable starch are heated to 90-110°C, sprayed on the urea granules at a rate of 2kg per minute with a two-fluid nozzle at an air atomization pressure of 4KPa, dried and screened to obtain coated urea with a diameter of 3-4mm S80; 3). Preparation of coated potassium sulfate S80: (a) Potassium sulfate is granulated and granulated by tableting or granulation, and potassium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating potassium sulfate S80 accounted for by coating S80 is 10-14, and the percentage by weight of potassium sulfate S80 of coating potassium sulfate S80 is 86-90 to select coating S80 and Potassium sulfate; preparation of coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 selection Clay minerals, biodegradable resins, plant starch and active agents; the biodegradable resins are dissolved in a mixed solution of 1/2 the weight of tetrachloromethane and tetrachloroethane, according to clay minerals, biodegradable resins, plants Starch and activating agent: the weight ratio of mixed solution=6-12: 90 choose mixed solution, add clay mineral, activating agent and plant starch and heat to 90-110 ℃, be 4KPa in air atomizing pressure with two-fluid nozzle, with every The rate of 2kg per minute is sprayed onto potassium sulfate granules, dried and screened to obtain coated potassium sulfate S80 with a diameter of 3-4mm; 4). Preparation of coated magnesium sulfate S80: (a) Magnesium sulfate is granulated and granulated by tableting or granulation, and magnesium sulfate particles with a diameter of 3-4 mm are selected, loaded into a fluidized bed, and heated To 60-80 DEG C; (b). The percentage by weight of coating magnesium sulfate S80 accounted for by coating S80 is 10-14, and the percentage by weight of magnesium sulfate accounted for coating magnesium sulfate S80 is 86-90 to select coating S80 and Magnesium sulfate; preparation of coating S80: according to the percentage by weight of each component of coating S80: clay mineral: 53-57, biodegradable resin: 36-40, active agent: 0.8-2, plant starch 4-8 selection Clay minerals, biodegradable resins, plant starch and active agents; the biodegradable resins are dissolved in a mixed solution of 1/2 the weight of tetrachloromethane and tetrachloroethane, according to clay minerals, biodegradable resins, plants Starch and activating agent: the weight ratio of mixed solution=6-12: 90 choose mixed solution, add clay mineral, activating agent and plant starch and heat to 90-110 ℃, be 4KPa in air atomizing pressure with two-fluid nozzle, with every The rate of 2kg per minute is sprayed onto magnesium sulfate particles, dried and screened to obtain coated magnesium sulfate S80 with a diameter of 3-4mm; 5). According to the percentage by weight of each raw material: coated urea 40: 29-35, coated urea S80: 6-10, ammonium phosphate: 8-12, coated potassium sulfate S80: 3-5, potassium sulfate: 14-18, coated magnesium sulfate S80: 5-7, magnesium sulfate: 21-27 select coated urea 40, coated urea S80, ammonium phosphate, coated potassium sulfate S80, potassium sulfate, coated magnesium sulfate S80 and sulfuric acid Magnesium raw materials are mixed to obtain products.