Functional controlled-release fertilizer for regulating and controlling productivity improvement of salinized soil and preparation method of functional controlled-release fertilizer

Abstract

The invention relates to the technical field of agricultural fertilizers, in particular to a functional sustained and controlled release fertilizer for regulating and controlling productivity of salinized soil and a preparation method thereof. The slow / controlled-release fertilizer is prepared by compounding a fertilizer matrix, a soil conditioner, a water-retaining agent and humic acid, wherein the fertilizer base body comprises a core material, and the surface of the core material is sequentially coated with a chelating layer and a wall material layer from inside to outside; the core material comprises the following components in parts by weight: ammonium sulfate, monoammonium phosphate, potassium sulfate and trace elements; the chelating layer is sodium ethylene diamine tetracetate; and the wall material layer is sodium alginate. The sodium alginate coating material adopted by the fertilizer can control the fertilizer to be slowly released in soil, and after the fertilizer is completely released in the soil, the adopted coated fertilizer is non-toxic and harmless in the soil and is easy to degrade. The chelating layer is arranged between the core material and the wall material and can be chelated to form a connecting structure of the inner layer and the outer layer, so that the strength of the fertilizer matrix particles is improved, the particles have stability, and the slow release effect is favorably exerted.

Description

Technical Field

[0001] The present invention relates to the technical field of agricultural fertilizers, and in particular to a functional slow-release fertilizer for regulating and improving the productivity of saline soil and a preparation method thereof. Background Art

[0002] Fertilizer refers to essential nutrients for plants. It is a type of substance that improves soil properties and increases soil fertility levels. It is one of the material bases of agricultural production. It mainly includes ammonium phosphate fertilizers, large-element water-soluble fertilizers, medium-element fertilizers, biological fertilizers, organic fertilizers, etc. Existing fertilizers have poor salt tolerance.

[0003] In recent years, excessive application of chemical fertilizers has further aggravated the degree of soil salinization. Soil salinization can also cause physiological drought in crop roots, resulting in low fertilizer utilization, affecting crop growth and development, and further affecting crop yield and quality. In the production of saline-alkali crops, the application of ordinary chemical fertilizers will cause excessive soil nutrient supply in the early stage of crop growth, and the crop is prone to fertilizer deficiency in the later stage of growth. The application of slow / controlled release fertilizers specifically for saline-alkali crops is an important technical approach to improve the yield and nutrient utilization rate of saline-alkali crops. At the same time, it has the advantages of convenient application, strong pertinence, increased crop yield and fertilization efficiency. At present, there are many studies on the use of slow / controlled release fertilizers to improve the yield and quality of crops in saline-alkali land, but the slow / controlled release fertilizers used are mostly sulfur-coated or resin-coated fertilizers. The disadvantages of these slow / controlled release fertilizers are high cost, complex processing technology, difficult degradation of membrane materials, organic materials as solvents and coating materials are easy to pollute the soil, and cannot improve the salt tolerance of crops on saline-alkali land, and the equipment has high energy consumption.

[0004] Slow-release fertilizer is a type of fertilizer that can slowly release nutrients, which can improve fertilizer utilization and reduce nutrient loss. For saline soil, due to its high soil salinity and poor fertility, functional slow-release fertilizers should not only consider the slow release of nutrients, but also focus on improving soil salinity and enhancing plant salt resistance. Summary of the invention

[0005] In response to the problem in the prior art that soil salinization affects crop yield and quality, the present invention provides a functional slow-release fertilizer and a preparation method for regulating the improvement of saline soil production capacity, which solves the problem in the prior art that soil salinization affects crop yield and quality and has the effect of improving soil salinization.

[0006] In a first aspect, the present invention provides a functional slow-release fertilizer for regulating the production capacity of saline soil, which is compounded by a fertilizer matrix, a soil conditioner, a water retaining agent, and humic acid; wherein the fertilizer matrix includes a core material, and the surface of the core material is sequentially coated with a chelating layer and a wall material layer from the inside to the outside; The core material includes the following components in parts by weight: ammonium sulfate, monoammonium phosphate, potassium sulfate, and trace elements; The chelating layer is sodium EDTA; The wall material layer is sodium alginate.

[0007] Furthermore, the weight ratio of the fertilizer base, the soil conditioner, the water retaining agent and the humic acid is 100:2~3:5~7:3~4.

[0008] Furthermore, the core material includes the following components in parts by weight: 15-20 parts of ammonium sulfate, 8-10 parts of monoammonium phosphate, 15-20 parts of potassium sulfate, and 1 part of trace elements.

[0009] Furthermore, the soil conditioner includes gypsum and zeolite powder in a weight ratio of 1:1.

[0010] Furthermore, the water retaining agent is polyacrylamide.

[0011] Furthermore, the trace element is at least one of borax, ferrous sulfate, zinc sulfate and magnesium sulfate.

[0012] In a second aspect, the present invention provides a method for preparing a functional slow-release fertilizer for regulating and improving the productivity of saline soil, comprising the following steps: (1) ammonium sulfate, monoammonium phosphate, potassium sulfate and trace elements are mixed in proportion, stirred and mixed evenly, and placed in a granulator for granulation to obtain a core material; (2) The core material particles are put into a fluidized bed coating machine, sodium EDTA is heated to a molten state, and the induced draft fan is turned on, and sodium EDTA is sprayed out from the bottom spray system of the fluidized bed coating machine to coat the core material particles, and then dried to obtain a core material coated with a chelating layer; (3) The core material coated with the chelating layer is placed in a rotary granulator for polishing and then put into a fluidized bed coater again. The acid solution of sodium alginate is sprayed from the bottom spray system of the fluidized bed coater to coat the core material coated with the chelating layer and dried to form a film.

[0013] Furthermore, in step (1), the stirring time is 30 min.

[0014] Furthermore, in step (2), the heating temperature is 275°C.

[0015] The beneficial effects of the present invention are: (1) The sodium alginate coating material used in the fertilizer of the present invention can control the slow release of the fertilizer in the soil, and after the fertilizer is completely released in the soil, the coated fertilizer used is non-toxic and harmless in the soil and is easily degradable.

[0016] (2) The present invention provides a chelating layer between the core material and the wall material. Sodium ethylenediaminetetraacetate as a chelating agent can chelate with trace elements in the core material and sodium alginate to form a connection structure between the inner layer and the outer layer, thereby improving the strength of the fertilizer matrix particles, making the particles stable and facilitating the slow-release effect.

[0017] (3) The gypsum in the soil conditioner of the present invention can react with sodium carbonate in the soil to generate sodium sulfate, thereby reducing soil alkalinity and improving soil structure; the zeolite powder has adsorption and ion exchange properties, and can absorb salt in the soil, thereby reducing harm to plants.

[0018] (4) The water retaining agent added at the same time in the present invention can absorb water and slowly release it, thereby maintaining soil moisture and reducing the number of irrigation times. It can also reduce the increase in soil salinity, thereby meeting the needs of improving the salt tolerance of crops in saline-alkali land and preventing and controlling environmental pollution caused by fertilization.

[0019] (5) The components of the present invention contain humic acid. When applied to saline-alkali soil, humic acid can absorb cations such as sodium, calcium, and magnesium in the soil, reduce the harm of salt to crops, and enhance the buffering capacity of the soil. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0021] Example 1 A functional slow-release fertilizer for regulating and improving the productivity of saline soil is composed of a compound of a fertilizer base, a soil conditioner, a water retaining agent, and humic acid, wherein the weight ratio of the fertilizer base, the soil conditioner, the water retaining agent, and the humic acid is 100:2:6:3.

[0022] The soil conditioner includes gypsum and zeolite powder in a weight ratio of 1:1; the water retaining agent is polyacrylamide; The fertilizer matrix includes a core material, and the surface of the core material is coated with a chelating layer and a wall material layer in sequence from the inside to the outside; The core material includes the following components by weight: 18 parts of ammonium sulfate, 9 parts of monoammonium phosphate, 18 parts of potassium sulfate, and 1 part of trace elements; the trace elements include borax, ferrous sulfate, zinc sulfate, and magnesium sulfate. The chelating layer is sodium ethylenediaminetetraacetate; and the wall material layer is sodium alginate.

[0023] A method for preparing a functional slow-release fertilizer for regulating and improving saline soil production capacity comprises the following steps: (1) Mix ammonium sulfate, monoammonium phosphate, potassium sulfate and trace elements in proportion, stir for 30 minutes to mix evenly, and place in a granulator for granulation to obtain core material; (2) The core material particles are put into a fluidized bed coating machine, sodium EDTA is heated to a molten state at 275°C, and the induced draft fan is turned on. The sodium EDTA is sprayed out from the bottom spray system of the fluidized bed coating machine to coat the core material particles, and the core material particles are dried to obtain a core material coated with a chelating layer; (3) The core material coated with the chelating layer is placed in a rotary granulator for polishing and then put into a fluidized bed coater again. The acid solution of sodium alginate is sprayed from the bottom spray system of the fluidized bed coater to coat the core material coated with the chelating layer and dried to form a film.

[0024] Example 2 A functional slow-release fertilizer for regulating and improving the productivity of saline soil is compounded by a fertilizer base, a soil conditioner, a water retaining agent, and humic acid, wherein the weight ratio of the fertilizer base, the soil conditioner, the water retaining agent, and the humic acid is 100:3:5:4.

[0025] The soil conditioner includes gypsum and zeolite powder in a weight ratio of 1:1; the water retaining agent is polyacrylamide; The fertilizer matrix includes a core material, and the surface of the core material is coated with a chelating layer and a wall material layer in sequence from the inside to the outside; The core material includes the following components by weight: 15 parts of ammonium sulfate, 8 parts of monoammonium phosphate, 15 parts of potassium sulfate, and 1 part of trace elements; the trace elements include borax, ferrous sulfate, zinc sulfate, and magnesium sulfate. The chelating layer is sodium ethylenediaminetetraacetic acid; and the wall material layer is sodium alginate.

[0026] The preparation method of Example 2 is the same as that of Example 1.

[0027] Example 3 A functional slow-release fertilizer for regulating and improving the productivity of saline soil is composed of a compound of a fertilizer base, a soil conditioner, a water retaining agent, and humic acid, wherein the weight ratio of the fertilizer base, the soil conditioner, the water retaining agent, and the humic acid is 100:2:7:4.

[0028] The soil conditioner includes gypsum and zeolite powder in a weight ratio of 1:1; the water retaining agent is polyacrylamide; The fertilizer matrix includes a core material, and the surface of the core material is coated with a chelating layer and a wall material layer in sequence from the inside to the outside; The core material includes the following components by weight: 20 parts of ammonium sulfate, 10 parts of monoammonium phosphate, 20 parts of potassium sulfate, and 1 part of trace elements; the trace elements include borax, ferrous sulfate, zinc sulfate, and magnesium sulfate. The chelating layer is sodium ethylenediaminetetraacetic acid; and the wall material layer is sodium alginate.

[0029] The preparation method of Example 3 is the same as that of Example 1.

[0030] Test Example 1 In order to further verify the technical effect of the fertilizer of the present invention, 10 mu of saline-alkali field was selected, and the specific use effect of the fertilizer of Example 1 prepared by the present invention was determined by planting wheat. The 10 mu of saline-alkali field was divided into two plots. The management mode of the two plots was the same during wheat planting. Fertilizer was applied at 3 kg / mu with an interval of 20 days. After two months, soil samples were taken from the two plots for nutrient determination. The data are shown in Table 1.

[0031] Table 1 Comparison before and after application of functional slow-release fertilizers to improve saline soil productivity

[0032] As shown in Table 1, the application of functional slow-release fertilizers for regulating the production capacity of saline soil can reduce the soil pH value and the soil salt content from 0.26% to 0.13%, while increasing the soil organic matter content, which has a good promoting effect on the growth and development of crops.

[0033] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and such changes or substitutions shall be within the scope of protection of the present invention.

Claims

1. A functional slow-release fertilizer for regulating and improving saline soil productivity, characterized in that: It is made of a compound of a fertilizer matrix, a soil conditioner, a water retaining agent, and humic acid; wherein the fertilizer matrix includes a core material, and the surface of the core material is coated with a chelating layer and a wall material layer in sequence from the inside to the outside; The core material includes the following components in parts by weight: ammonium sulfate, monoammonium phosphate, potassium sulfate, and trace elements; The chelating layer is sodium EDTA; The wall material layer is sodium alginate.

2. The functional slow-release fertilizer for regulating and improving saline soil productivity according to claim 1, characterized in that: The weight ratio of fertilizer base, soil conditioner, water retaining agent and humic acid is 100:2~3:5~7:3~4.

3. The functional slow-release fertilizer for regulating and improving saline soil productivity according to claim 1, characterized in that: The core material comprises the following components in parts by weight: 15-20 parts of ammonium sulfate, 8-10 parts of monoammonium phosphate, 15-20 parts of potassium sulfate and 1 part of trace elements.

4. The functional slow-release fertilizer for regulating and improving saline soil productivity according to claim 2, characterized in that: The soil conditioner includes gypsum and zeolite powder in a weight ratio of 1:

1.

5. The functional slow-release fertilizer for regulating and improving the productivity of saline soil according to claim 2, characterized in that: The water retaining agent is polyacrylamide.

6. The functional slow-release fertilizer for regulating and improving the productivity of saline soil according to claim 2, characterized in that: The trace element is at least one of borax, ferrous sulfate, zinc sulfate and magnesium sulfate.

7. The method for preparing a functional slow-release fertilizer for regulating and improving saline soil productivity according to claim 1, characterized in that: The steps include: (1) ammonium sulfate, monoammonium phosphate, potassium sulfate and trace elements are mixed in proportion, stirred and mixed evenly, and placed in a granulator for granulation to obtain a core material; (2) The core material particles are put into a fluidized bed coating machine, sodium EDTA is heated to a molten state, and the induced draft fan is turned on, and sodium EDTA is sprayed out from the bottom spray system of the fluidized bed coating machine to coat the core material particles, and then dried to obtain a core material coated with a chelating layer; (3) The core material coated with the chelating layer is placed in a rotary granulator for polishing and then put into a fluidized bed coater again. The acid solution of sodium alginate is sprayed from the bottom spray system of the fluidized bed coater to coat the core material coated with the chelating layer and dried to form a film.

8. The method for preparing a functional slow-release fertilizer for regulating and improving saline soil productivity as claimed in claim 7, characterized in that: In step (1), the stirring time is 30 min.

9. The method for preparing a functional slow-release fertilizer for regulating and improving saline soil productivity according to claim 7, characterized in that: In step (2), the heating temperature is 275°C.

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