Instant bulk blending fertilizer for improving soil and preparation method thereof

Abstract

The invention provides an instant blended fertilizer for improving soil and a preparation method thereof, and relates to the technical field of fertilizers. The instant bulk blending fertilizer for improving soil is prepared from the following raw materials in parts by weight: 20 to 25 parts of urea, 10 to 16 parts of diammonium phosphate, 12 to 14 parts of potassium sulfate, 3 to 4 parts of magnesium sulfate, 5 to 6 parts of potassium humate, 4 to 5 parts of lignin, 0.1 to 0.3 part of zinc oxide, 0.5 to 0.6 part of manganese sulfate, 0.5 to 1 part of ammonium molybdate, 6 to 10 parts of coating material and 10 to 12 parts of water. The instant blended fertilizer for improving soil has the advantages of balanced nutrition, good instant solubility, high nutrient utilization rate, remarkable soil improvement effect and the like. Popularization and application of the bulk blending fertilizer help to improve fertility level of farmland and promote sustainable development of agriculture.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a quick-dissolving mixed fertilizer for improving soil and a preparation method thereof. Background Art

[0002] In agricultural production, soil quality and fertility have a vital impact on crop growth and yield. However, due to long-term farming and excessive use of chemical fertilizers, the structure and fertility of the soil are often damaged to varying degrees, leading to soil acidification, nutrient imbalance and other problems. In order to solve these problems, it is particularly important to develop an instant blended fertilizer that can improve soil and increase soil fertility.

[0003] There are many types of traditional fertilizers, including nitrogen fertilizer, phosphorus fertilizer, potassium fertilizer, etc., but these single fertilizers often cannot meet the needs of crops for multiple nutrients, and excessive use can easily lead to soil pollution and nutrient waste. In contrast, blended fertilizers are made by mixing two or more granular fertilizers by physical methods, which can achieve the synergistic effect of multiple fertilizers, improve fertilizer utilization efficiency, and meet the various nutritional needs of crops.

[0004] The preparation process of blended fertilizers usually includes the selection and processing of fertilizer raw materials, determination of blending ratio, selection of mixing equipment, control of the mixing process, and packaging and storage of blended fertilizers. In the selection of fertilizer raw materials, suitable fertilizer raw materials such as urea, diammonium phosphate, potash fertilizer, etc. can be selected according to the needs of crops and the fertility of the soil. After these raw materials are crushed, screened, etc., they are evenly mixed in a certain proportion to form a blended fertilizer with balanced nutrition and high utilization rate.

[0005] However, existing blended fertilizers still have some deficiencies in improving soil. For example, although some blended fertilizers can provide the nutrients required by crops, they lack the effect of improving soil structure; although other blended fertilizers have added soil conditioners, the conditioning effect is limited, and there are often problems such as uneven nutrient release and low utilization rate. Based on this, the present invention provides a method and coating for improving soil with instant blended fertilizers. Summary of the invention

[0006] The invention aims to provide a quick-dissolving mixed fertilizer for improving soil and a preparation method thereof, which has the advantages of balanced nutrition, good quick solubility, high nutrient utilization rate, significant soil improvement effect and the like.

[0007] On the one hand, the present invention provides an instant mixed fertilizer for improving soil, comprising the following raw materials in parts by weight: 20-25 parts of urea, 10-16 parts of diammonium phosphate, 12-14 parts of potassium sulfate, 3-4 parts of magnesium sulfate, 5-6 parts of potassium humate, 4-5 parts of lignin, 0.1-0.3 parts of zinc oxide, 0.5-0.6 parts of manganese sulfate, 0.5-1 parts of ammonium molybdate, 6-10 parts of coating material and 10-12 parts of water.

[0008] Furthermore, the coating material comprises attapulgite-modified gypsum and wax in a weight ratio of (5-6):1.

[0009] The compound of attapulgite modified gypsum and wax in the present invention can not only play a coating and slow-release effect on the basic fertilizer, but also improve the instant solubility of the fertilizer. From the coating level, attapulgite has a unique crystal structure and a large specific surface area, which can absorb and fix a large amount of water and nutrients; when gypsum is combined with attapulgite for modification, the attapulgite modified gypsum formed has a stronger adsorption capacity and ion exchange capacity; in the fertilizer preparation process, attapulgite modified gypsum as a coating material can be tightly coated around the core components of the fertilizer to form a stable protective film; this protective film can control the release rate of nutrients, so that the nutrients are slowly released in the soil, and the effective period of the fertilizer is extended. Wax is a hydrophobic substance that can prevent external factors such as moisture and oxygen from directly contacting the core components of the fertilizer. When wax is compounded with attapulgite modified gypsum, the wax can further enhance the stability and slow-release effect of the coating material; the hydrophobicity of the wax can slow down the erosion of water on the fertilizer, thereby extending the release time of the fertilizer. From the perspective of rapid dissolution, the crystal structure of attapulgite contains a large number of micropores and channels, which can absorb and retain a certain amount of moisture; when the fertilizer is applied to the soil, the moisture in the soil will gradually penetrate into the coating layer and react with the attapulgite-modified gypsum; the attapulgite-modified gypsum can quickly absorb and retain the moisture to form a moist film; this moist film can accelerate the dissolution and release of the core components of the fertilizer, thereby improving the solubility of the fertilizer; although the wax itself does not have the effect of improving the solubility of the fertilizer, its presence in the coating material can affect the structure and properties of the coating layer; this helps to maintain a moist environment inside the coating layer, thereby indirectly promoting the dissolution and release of the fertilizer.

[0010] Furthermore, the preparation method of the attapulgite modified gypsum comprises: mixing and stirring the pretreated attapulgite, gypsum powder and ethanol, adding sodium dodecylbenzene sulfonate and continuing to stir at room temperature for 20-24 hours, drying in an oven at 75-85° C. to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum.

[0011] Furthermore, the pretreatment step of the attapulgite includes: soaking the attapulgite in sulfuric acid with a mass concentration of 20-24% for 20-24 hours, washing it with deionized water for 2-4 times, drying it at 55-65°C, and sieving to obtain pretreated attapulgite with an average particle size of 300-500 meshes.

[0012] Furthermore, the average particle size of the gypsum powder is 100-120 meshes.

[0013] Furthermore, the dosage ratio of the pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is (9-11) g: (3-4) g: (50-60) mL: (0.5-0.7) g.

[0014] On the other hand, the present invention also provides a method for preparing a quick-dissolving blended fertilizer for improving soil, the steps comprising: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, spraying water thereon, mixing evenly and then granulating to obtain a blended fertilizer.

[0015] Furthermore, the stirring and mixing is performed at a rotation speed of 100-110 rpm and for a time of 40-60 min.

[0016] Furthermore, the average particle size of the blended fertilizer is 3-5 mm.

[0017] The beneficial effects of the present invention are:

[0018] The blended fertilizer prepared in the present invention contains a variety of nutrient elements, such as nitrogen (from urea, diammonium phosphate), phosphorus (from diammonium phosphate), potassium (from potassium sulfate, potassium humate), magnesium (from magnesium sulfate), zinc (from zinc oxide), manganese (from manganese sulfate) and molybdenum (from ammonium molybdate). These elements are necessary for crop growth, and there is a certain synergistic effect between different elements. By scientifically proportioning these elements, the nutrient requirements of crops at different growth stages can be met, balanced nutrient supply can be achieved, and healthy growth of crops can be promoted.

[0019] The blended fertilizer prepared in the present invention has instant solubility, and the urea, diammonium phosphate, potassium sulfate and the like in the raw materials are all water-soluble fertilizers, which can be quickly dissolved in water and absorbed and utilized by the root system of crops. In addition, the dissolution speed and dissolution rate of the fertilizer are further improved by coating treatment. This instant solubility helps to realize the integrated management of water and fertilizer, improve the utilization rate of fertilizer, and reduce nutrient loss.

[0020] The present invention adopts coating technology and other means to coat the blended fertilizer to improve its solubility and nutrient utilization rate. After coating, the fertilizer can dissolve quickly in the soil, release nutrients for crops to absorb and utilize, while reducing nutrient loss and waste, and increasing the effective period of the fertilizer. In addition, the addition of organic components such as potassium humate and lignin can also improve the soil structure, improve the soil's fertility absorption and fertility retention, and further promote the absorption and utilization of nutrients.

[0021] The coating material used in the present invention is a composite of attapulgite modified gypsum and wax. The attapulgite modified gypsum has good adsorption and ion exchange capacity, and can adsorb and retain a certain amount of moisture. When the fertilizer is applied to the soil, the coating material gradually decomposes and releases the water-soluble fertilizer components inside. Due to the moisturizing effect of the attapulgite modified gypsum, the fertilizer components are more easily dissolved in the soil, thereby improving the instant solubility of the fertilizer. In addition, the addition of wax also plays a role in protecting the fertilizer components and preventing them from decomposing too quickly, thereby ensuring that the fertilizer can be quickly dissolved and release nutrients when needed.

[0022] In addition, the coating material controls the release rate of the fertilizer, achieving a slow release and continuous supply of nutrients. This helps reduce the loss and fixation of nutrients and improves the utilization rate of nutrients. The ion exchange capacity of attapulgite-modified gypsum can adsorb and fix certain nutrients in the soil (such as potassium, magnesium, etc.) to prevent them from being leached or lost. At the same time, the hydrophobicity of the wax can reduce the direct erosion of water on the fertilizer, further extending the effective period of the fertilizer. These mechanisms work together to significantly improve the nutrient utilization rate of the blended fertilizer.

[0023] The organic components such as potassium humate and lignin and the inorganic components such as attapulgite-modified gypsum in the blended fertilizer of the present invention have a good improvement effect on the soil. They can increase the organic matter content of the soil, improve the soil microbial ecological environment, and increase the soil fertility and air permeability. At the same time, these components can also adjust the soil acidity and alkalinity, alleviate the problems of soil compaction, and provide a good soil environment for crop growth. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is 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 are within the scope of protection of the present invention.

[0025] Example 1

[0026] This embodiment provides a quick-dissolving blended fertilizer for improving soil, which comprises the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 part of zinc oxide, 0.55 part of manganese sulfate, 0.7 part of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0027] Among them, the coating material comprises attapulgite-modified gypsum and wax with a weight ratio of 5.5:1;

[0028] Pretreatment of attapulgite: Attapulgite is soaked in sulfuric acid with a mass concentration of 21% for 22 h, then washed 3 times with deionized water, dried at 60 °C, and sieved to obtain pretreated attapulgite with an average particle size of 400 mesh;

[0029] The preparation method of attapulgite-modified gypsum includes: mixing and stirring pretreated attapulgite, gypsum powder with an average particle size of 110 mesh and ethanol, adding sodium dodecylbenzenesulfonate, and continuing to stir at room temperature for 22 h, then drying to constant weight in an oven at 80 °C, and grinding and sieving through a 200-mesh sieve to obtain it; the dosage ratio of pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzenesulfonate is 10 g:3.5 g:55 mL:0.6 g;

[0030] The preparation method of the quick-dissolving blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and coating material, spraying water into it, with the stirring speed of 105 rpm and the time of 50 min, and granulating after mixing evenly to obtain the blended fertilizer, and the average particle size of the obtained blended fertilizer is 4 mm.

[0031] Example 2

[0032] This embodiment provides a quick-dissolving blended fertilizer for improving soil, which comprises the following raw materials in parts by weight: 23 parts of urea, 12 parts of diammonium phosphate, 12 parts of potassium sulfate, 3 parts of magnesium sulfate, 5 parts of potassium humate, 4 parts of lignin, 0.2 part of zinc oxide, 0.5 part of manganese sulfate, 0.5 part of ammonium molybdate, 8 parts of coating material and 10 parts of water;

[0033] Among them, the coating material comprises attapulgite-modified gypsum and wax with a weight ratio of 5:1;

[0034] Pretreatment of attapulgite: Attapulgite is soaked in sulfuric acid with a mass concentration of 21% for 20 h, then washed 3 times with deionized water, dried and sieved at 60 °C to obtain pretreated attapulgite with an average particle size of 400 mesh;

[0035] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated attapulgite, gypsum powder with an average particle size of 110 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing to stir at room temperature for 20 hours, drying in an oven at 75°C to constant weight, and grinding through a 200-mesh sieve to obtain the attapulgite modified gypsum; the amount ratio of pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 9g:3g:50mL:0.5g;

[0036] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 100 rpm, the time is 40 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 3 mm.

[0037] Example 3

[0038] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 24 parts of urea, 14 parts of diammonium phosphate, 13 parts of potassium sulfate, 4 parts of magnesium sulfate, 6 parts of potassium humate, 5 parts of lignin, 0.3 parts of zinc oxide, 0.6 parts of manganese sulfate, 1 part of ammonium molybdate, 10 parts of coating material and 12 parts of water;

[0039] Wherein, the coating material comprises attapulgite-modified gypsum and wax in a weight ratio of 6:1;

[0040] Pretreatment of attapulgite: After soaking the attapulgite in 24% sulfuric acid for 24 hours, the attapulgite was washed with deionized water for 3 times, dried and sieved at 60°C to obtain the pretreated attapulgite with an average particle size of 500 meshes;

[0041] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated attapulgite, gypsum powder with an average particle size of 120 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing stirring at room temperature for 24 hours, drying in an oven at 85°C to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum; the amount ratio of pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 11g:4g:60mL:0.7g;

[0042] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 110 rpm, the time is 40 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 5 mm.

[0043] Example 4

[0044] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 20 parts of urea, 16 parts of diammonium phosphate, 12 parts of potassium sulfate, 4 parts of magnesium sulfate, 5 parts of potassium humate, 4 parts of lignin, 0.3 parts of zinc oxide, 0.5 parts of manganese sulfate, 1 part of ammonium molybdate, 8 parts of coating material and 12 parts of water;

[0045] Wherein, the coating material comprises attapulgite-modified gypsum and wax in a weight ratio of 6:1;

[0046] Pretreatment of attapulgite: After soaking the attapulgite in 24% sulfuric acid for 24 hours, the attapulgite was washed with deionized water for 4 times, dried and sieved at 65°C to obtain the pretreated attapulgite with an average particle size of 400 meshes;

[0047] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated attapulgite, gypsum powder with an average particle size of 110 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing to stir at room temperature for 24 hours, drying in an oven at 80°C to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum; the amount ratio of pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 10g:4g:50mL:0.5g;

[0048] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 100 rpm, the time is 60 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0049] Comparative Example 1

[0050] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0051] Wherein, the coating material comprises kaolin-modified gypsum and wax in a weight ratio of 5.5:1;

[0052] Pretreatment of kaolin: After soaking the kaolin in 21% sulfuric acid for 22 hours, the kaolin was washed with deionized water for 3 times, dried and sieved at 60°C to obtain pretreated kaolin with an average particle size of 400 meshes;

[0053] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated kaolin, gypsum powder with an average particle size of 110 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing stirring at room temperature for 22 hours, drying in an oven at 80°C to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum; the amount ratio of pretreated kaolin, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 10g:3.5g:55mL:0.6g;

[0054] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0055] Comparative Example 2

[0056] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0057] Wherein, the coating material comprises bentonite-modified gypsum and wax in a weight ratio of 5.5:1;

[0058] Pretreatment of bentonite: After the bentonite was soaked in 21% sulfuric acid for 22 hours, it was washed with deionized water for 3 times, dried and sieved at 60°C to obtain pretreated bentonite with an average particle size of 400 meshes;

[0059] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated bentonite, gypsum powder with an average particle size of 110 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing to stir at room temperature for 22 hours, drying in an oven at 80°C to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum; the amount ratio of the pretreated bentonite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 10g:3.5g:55mL:0.6g;

[0060] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0061] Comparative Example 3

[0062] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0063] Wherein, the coating material comprises gypsum and wax in a weight ratio of 5.5:1;

[0064] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0065] Comparative Example 4

[0066] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0067] Wherein, the coating material comprises attapulgite and wax in a weight ratio of 5.5:1;

[0068] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0069] Comparative Example 5

[0070] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0071] Wherein, the coating material is wax;

[0072] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0073] Comparative Example 6

[0074] The present embodiment provides an instant blended fertilizer for improving soil, comprising the following raw materials in parts by weight: 22 parts of urea, 13 parts of diammonium phosphate, 13 parts of potassium sulfate, 3.5 parts of magnesium sulfate, 5.5 parts of potassium humate, 4.5 parts of lignin, 0.2 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of coating material and 11 parts of water;

[0075] Wherein, the coating material is attapulgite-modified gypsum;

[0076] Pretreatment of attapulgite: After soaking the attapulgite in 21% sulfuric acid for 22 hours, the attapulgite was washed with deionized water for 3 times, dried and sieved at 60°C to obtain the pretreated attapulgite with an average particle size of 400 meshes;

[0077] The preparation method of attapulgite modified gypsum comprises: mixing and stirring pretreated attapulgite, gypsum powder with an average particle size of 110 meshes and ethanol, adding sodium dodecylbenzene sulfonate and continuing to stir at room temperature for 22 hours, drying in an oven at 80°C to constant weight, and grinding through a 200-mesh sieve to obtain the gypsum; the amount ratio of pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is 10g:3.5g:55mL:0.6g;

[0078] The preparation method of the instant blended fertilizer for improving soil in this embodiment includes: stirring and mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, and spraying water thereon, the stirring and mixing speed is 105 rpm, the time is 50 minutes, and after mixing evenly, granulation is performed to obtain a blended fertilizer, and the average particle size of the blended fertilizer is 4 mm.

[0079] Test Example: The performance of the blended fertilizers prepared in Examples 1-4 and Comparative Examples 1-6 was tested as follows.

[0080] 1. Fertilizer utilization rate: Tomato was used as the test target crop, 110 tomato seedlings with basically the same growth were taken and set into 11 groups, with 10 seedlings in each group. The fertilization method for each group of Examples 1-4 and Comparative Examples 1-6 was as follows: first, the prepared blended fertilizer was diluted with 50 times the weight of the blended fertilizer using water to obtain a total of 1.5 L of a mixture of fertilizer and water, which was applied once in each group of soil, and fertilized once every 10 days until one week before the fruit was harvested. The blank control group was directly fertilized with the same amount of water without adding any fertilizer, and the average plant yield was calculated;

[0081] 2. Stability test: refer to HG / T 4135-2010 "Stable Fertilizer" urea residual difference rate; the greater the urea residual difference rate, the higher the stability;

[0082] 3. Fertilizer effective period: refer to the 28-day cumulative nutrient release rate in GB23348-2009 "Slow-release fertilizer"; the lower the release rate, the longer the fertilizer effective period;

[0083] The test results are shown in Table 1:

[0084] Table 1: Effect test

[0085]

[0086]

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. All technical solutions and improvements that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A quick-dissolving blended fertilizer for improving soil, characterized in that: The invention comprises the following raw materials in parts by weight: 20-25 parts of urea, 10-16 parts of diammonium phosphate, 12-14 parts of potassium sulfate, 3-4 parts of magnesium sulfate, 5-6 parts of potassium humate, 4-5 parts of lignin, 0.1-0.3 parts of zinc oxide, 0.5-0.6 parts of manganese sulfate, 0.5-1 parts of ammonium molybdate, 6-10 parts of coating material and 10-12 parts of water.

2. The instant mixed fertilizer for improving soil according to claim 1, characterized in that: The coating material comprises attapulgite-modified gypsum and wax in a weight ratio of (5-6):

1.

3. The instant blended fertilizer for improving soil according to claim 1, characterized in that: The preparation method of the attapulgite modified gypsum comprises: mixing and stirring pretreated attapulgite, gypsum powder and ethanol, adding sodium dodecylbenzene sulfonate and continuing stirring at room temperature for 20-24 hours, drying in an oven at 75-85° C. to constant weight, and grinding through a 200-mesh sieve to obtain the attapulgite modified gypsum.

4. The instant mixed fertilizer for improving soil according to claim 1, characterized in that: The pretreatment step of the attapulgite comprises: soaking the attapulgite in sulfuric acid with a mass concentration of 20-24% for 20-24 hours, washing it with deionized water for 2-4 times, drying it at 55-65° C., and sieving to obtain the pretreated attapulgite with an average particle size of 300-500 meshes.

5. The instant mixed fertilizer for improving soil according to claim 4, characterized in that: The average particle size of the gypsum powder is 100-120 meshes.

6. The instant mixed fertilizer for improving soil according to claim 4, characterized in that: The dosage ratio of the pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzene sulfonate is (9-11) g: (3-4) g: (50-60) mL: (0.5-0.7) g.

7. A method for preparing the instant blended fertilizer for improving soil according to any one of claims 1 to 6, characterized in that the steps include: Urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and coating materials are stirred and mixed, and water is sprayed thereon. After mixing evenly, granulation is performed to obtain a blended fertilizer.

8. The method for preparing a quick-dissolving blended fertilizer for improving soil according to claim 7, wherein the stirring and mixing is performed at a speed of 100-110 rpm and for a time of 40-60 min.

9. The method for preparing a quick-dissolving blended fertilizer for improving soil according to claim 7, characterized in that: The average particle size of the blended fertilizer is 3-5 mm.

Images