A quick-dissolving mixed fertilizer for improving soil and a preparation method thereof

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fertilizers, in particular to a quick-dissolving mixed fertilizer for soil improvement and a preparation method thereof. BACKGROUND

[0002] In agricultural production, the quality and fertility of soil have a crucial impact on the growth and yield of crops. However, due to long-term cultivation and excessive use of chemical fertilizers, the structure and fertility of soil are often damaged to varying degrees, leading to problems such as soil acidification and nutrient imbalance. In order to solve these problems, it is particularly important to develop a quick-dissolving mixed fertilizer that can improve soil and increase soil fertility.

[0003] Traditional fertilizers are diverse, including nitrogen fertilizers, phosphorus fertilizers, potassium fertilizers, etc. However, these single fertilizers often cannot meet the demand of crops for multiple nutrients, and excessive use can lead to soil pollution and nutrient waste. In contrast, mixed fertilizers are made by physically mixing two or more granular fertilizers, which can achieve the synergistic effect of multiple fertilizers, improve the utilization efficiency of fertilizers, and meet the nutritional needs of crops.

[0004] The preparation process of mixed fertilizers usually includes the selection and treatment of fertilizer raw materials, the determination of mixing ratio, the selection of mixing equipment, the control of mixing process, and the packaging and storage of mixed fertilizers. In the selection of fertilizer raw materials, suitable fertilizer raw materials such as urea, diammonium phosphate, and potassium fertilizer can be selected according to the demand of crops and the fertility status of soil. After these raw materials are crushed, screened, and other treatments, they are mixed uniformly according to a certain ratio to form a mixed fertilizer with balanced nutrition and high utilization rate.

[0005] However, existing mixed fertilizers still have some deficiencies in improving soil. For example, some mixed fertilizers can provide the nutrients required by crops, but lack the improvement effect on soil structure; another mixed fertilizer adds soil conditioners, but the conditioning effect is limited, and often has problems such as uneven nutrient release and low utilization rate. Based on this, the present application provides a method for preparing a quick-dissolving mixed fertilizer for soil improvement and a coating. SUMMARY

[0006] The purpose of the present application is to provide a quick-dissolving mixed fertilizer for soil improvement and a preparation method thereof, which has the advantages of balanced nutrition, good quick-dissolving property, high nutrient utilization rate, and significant soil improvement effect.

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

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

[0009] In the application, the combination of palygorskite modified gypsum and wax not only plays a role in coating and slow release of base fertilizer, but also improves the instant solubility of the fertilizer. From the aspect of coating, palygorskite has a unique crystal structure and a large specific surface area, which can adsorb and fix a large amount of water and nutrients; after modification of gypsum combined with palygorskite, the palygorskite modified gypsum has stronger adsorption capacity and ion exchange capacity; during the preparation of the fertilizer, the palygorskite modified gypsum as a coating material can tightly coat around the core components of the fertilizer to form a stable protective film; this protective film can control the release rate of nutrients, allowing the nutrients to be released slowly in the soil and prolonging the effective period of the fertilizer. Wax is a hydrophobic substance that can prevent water and oxygen and other external factors from directly contacting the core components of the fertilizer. When wax is combined with palygorskite 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 prolonging the release time of the fertilizer. From the aspect of instant solubility, the crystal structure of palygorskite contains a large number of micropores and channels, which can adsorb and retain a certain amount of water; after the fertilizer is applied to the soil, the water in the soil will gradually penetrate into the coating layer and react with the palygorskite modified gypsum; the palygorskite modified gypsum can quickly absorb and retain these water, forming a moist film; this moist film can accelerate the dissolution and release of the core components of the fertilizer, thereby improving the instant solubility of the fertilizer; although wax itself does not have the function of improving the instant solubility of the fertilizer, its presence in the coating material can affect the structure and performance 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] Further, the preparation method of the palygorskite modified gypsum comprises: mixing and stirring the pretreated palygorskite, gypsum powder and ethanol, adding sodium dodecyl benzene sulfonate and continuing to stir at room temperature for 20-24 hours, drying in an oven at 75-85°C until constant weight, grinding through a 200 mesh sieve, and obtaining the product.

[0011] Further, 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 with deionized water for 2-4 times, drying at 55-65°C, and sieving to obtain the pretreated attapulgite with an average particle size of 300-500 mesh.

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

[0013] Further, the use amount ratio of the pretreated attapulgite, the gypsum powder, the ethanol, and the sodium dodecyl benzene sulfonate is (9-11) g:(3-4) g:(50-60) mL:(0.5-0.7) g.

[0014] In another aspect, the application also provides a preparation method of the instant mixed fertilizer for improving soil, including the steps of: mixing urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate, and a coating material, spraying water thereinto, and granulating after uniform mixing to obtain the mixed fertilizer.

[0015] Further, the stirring speed is 100-110 rpm, and the stirring time is 40-60 minutes.

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

[0017] The application has the following beneficial effects:

[0018] The mixed fertilizer prepared in the application contains various nutrient elements, such as nitrogen (from urea and diammonium phosphate), phosphorus (from diammonium phosphate), potassium (from potassium sulfate and potassium humate), magnesium (from magnesium sulfate), zinc (from zinc oxide), manganese (from manganese sulfate), and molybdenum (from ammonium molybdate). These elements are essential 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 nutrition supply is realized, and the healthy growth of crops is promoted.

[0019] The mixed fertilizer prepared in the application has instant solubility. Urea, diammonium phosphate, potassium sulfate, etc. in the raw materials are water-soluble fertilizers, which can be quickly dissolved in water and absorbed and utilized by crop roots. In addition, through the coating treatment, the dissolution speed and dissolution rate of the fertilizer are further improved. This instant solubility helps to realize water and fertilizer integration management, improve fertilizer utilization rate, and reduce nutrient loss.

[0020] The present application adopts film coating technology and other means to coat the blended fertilizer to improve its quick solubility and nutrient utilization rate. After coating, the fertilizer can quickly dissolve in the soil, release nutrients for crop absorption and utilization, and reduce nutrient loss and waste, thereby prolonging the fertilizer's effective period. In addition, the addition of organic components such as potassium humate and lignin can also improve soil structure, increase soil fertility and fertility, and further promote nutrient absorption and utilization.

[0021] The coating material used in the present application is a combination 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 water. When the fertilizer is applied to the soil, the coating material gradually decomposes and releases the water-soluble fertilizer components inside. Due to the moisture retention effect of the attapulgite modified gypsum, the fertilizer components are more easily dissolved in the soil, improving the quick solubility of the fertilizer. In addition, the addition of wax also plays a protective role for the fertilizer components, preventing their rapid decomposition, thereby ensuring that the fertilizer can quickly dissolve and release nutrients when needed.

[0022] In addition, the coating material controls the release rate of the fertilizer, achieving slow release and continuous supply of nutrients. This helps to reduce nutrient loss and fixation, and improves nutrient utilization. The ion exchange capacity of the attapulgite modified gypsum can adsorb and fix certain nutrients in the soil (such as potassium, magnesium, etc.), preventing 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 prolonging 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 in the blended fertilizer of the present application, as well as the inorganic components such as attapulgite modified gypsum, have good improvement effect on the soil. They can increase the soil organic matter content, improve the soil microbial ecological environment, and improve the soil fertility and air permeability. At the same time, these components can also adjust the soil acidity and alkalinity, alleviate the problem of soil compaction, and provide a good soil environment for crop growth. DETAILED DESCRIPTION

[0024] The technical solutions of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are part of the embodiments of the present application, but not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] Example 1

[0026] The embodiment provides a quick-dissolving mixed 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 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;

[0027] The coating material comprises attapulgite modified gypsum and wax at a ratio of 5.5:1 by weight;

[0028] The pretreatment of attapulgite is as follows: after the attapulgite is soaked in 21% sulfuric acid for 22 hours, the attapulgite is washed with deionized water for three times, dried at 60 DEG C, and sieved to obtain the pretreated attapulgite with an average particle size of 400 mesh;

[0029] The preparation method of the attapulgite modified gypsum comprises the following steps: the pretreated attapulgite, gypsum powder with an average particle size of 110 mesh and ethanol are mixed and stirred, sodium dodecyl benzene sulfonate is added, and the stirring is continued at room temperature for 22 hours; the mixture is dried in an oven at 80 DEG C until the weight is constant; and the mixture is ground through a 200 mesh sieve to obtain the attapulgite modified gypsum; the dosages of the pretreated attapulgite, gypsum powder, ethanol and sodium dodecyl benzene sulfonate are 10 g: 3.5 g: 55 mL: 0.6 g;

[0030] The preparation method of the quick-dissolving mixed fertilizer for improving soil in the embodiment comprises the following steps: urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material are mixed and stirred, water is sprayed into the mixture, the stirring speed is 105 rpm, the stirring time is 50 minutes, the mixture is uniformly mixed, and granulation is performed to obtain the mixed fertilizer; and the average particle size of the mixed fertilizer is 4 mm.

[0031] Embodiment 2

[0032] The embodiment provides a quick-dissolving mixed 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 parts of zinc oxide, 0.5 parts of manganese sulfate, 0.5 parts of ammonium molybdate, 8 parts of a coating material and 10 parts of water;

[0033] The coating material comprises attapulgite modified gypsum and wax at a ratio of 5:1 by weight;

[0034] The pretreatment of attapulgite is as follows: after the attapulgite is soaked in 21% sulfuric acid for 20 hours, the attapulgite is washed with deionized water for three times, dried at 60 DEG C, and sieved to obtain the pretreated attapulgite with an average particle size of 400 mesh;

[0035] The preparation method of the attapulgite modified gypsum comprises the following steps: mixing and stirring the pretreated attapulgite, the gypsum powder with an average particle size of 110 mesh and ethanol, adding sodium dodecyl benzene sulfonate, continuously stirring for 20 hours at room temperature, drying in an oven at 75 DEG C until constant weight, grinding through a 200 mesh sieve, and obtaining the product; the dosage ratio of the pretreated attapulgite, the gypsum powder, ethanol and sodium dodecyl benzene sulfonate is 9g:3g:50mL:0.5g;

[0036] The preparation method of the instant soil-improving mixed fertilizer in the embodiment comprises the following steps: mixing and stirring urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, spraying water thereinto, stirring at a speed of 100 rpm for 40 minutes, uniformly mixing, and granulating to obtain the mixed fertilizer, wherein the average particle size of the mixed fertilizer is 3 mm.

[0037] Embodiment 3

[0038] The instant soil-improving mixed fertilizer provided in the embodiment comprises the following raw materials in parts by weight: urea 24 parts, diammonium phosphate 14 parts, potassium sulfate 13 parts, magnesium sulfate 4 parts, potassium humate 6 parts, lignin 5 parts, zinc oxide 0.3 parts, manganese sulfate 0.6 parts, ammonium molybdate 1 part, coating material 10 parts and water 12 parts.

[0039] The coating material comprises attapulgite modified gypsum and wax at a ratio of 6:1 by weight.

[0040] The pretreatment of the attapulgite comprises the following steps: immersing the attapulgite in 24% sulfuric acid for 24 hours, washing with deionized water for 3 times, drying at 60 DEG C, and sieving to obtain the pretreated attapulgite with an average particle size of 500 mesh.

[0041] The preparation method of the attapulgite modified gypsum comprises the following steps: mixing and stirring the pretreated attapulgite, the gypsum powder with an average particle size of 120 mesh and ethanol, adding sodium dodecyl benzene sulfonate, continuously stirring for 24 hours at room temperature, drying in an oven at 85 DEG C until constant weight, grinding through a 200 mesh sieve, and obtaining the product; the dosage ratio of the pretreated attapulgite, the gypsum powder, ethanol and sodium dodecyl benzene sulfonate is 11g:4g:60mL:0.7g.

[0042] The preparation method of the instant soil-improving mixed fertilizer in the embodiment comprises the following steps: mixing and stirring urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, spraying water thereinto, stirring at a speed of 110 rpm for 40 minutes, uniformly mixing, and granulating to obtain the mixed fertilizer, wherein the average particle size of the mixed fertilizer is 5 mm.

[0043] Embodiment 4

[0044] The embodiment provides a quick-dissolving mixed fertilizer for improving soil, which comprises 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] The coating material comprises attapulgite modified gypsum and wax at a ratio of 6:1 by weight.

[0046] The pretreatment of attapulgite is as follows: after the attapulgite is soaked in 24% sulfuric acid for 24 hours, the attapulgite is cleaned with deionized water for four times, and then is dried at 65 DEG C and sieved to obtain the pretreated attapulgite with an average particle size of 400 mesh.

[0047] The preparation method of the attapulgite modified gypsum comprises the following steps: the pretreated attapulgite, gypsum powder with an average particle size of 110 mesh and ethanol are mixed and stirred, sodium dodecyl benzene sulfonate is added, and then the mixture is continuously stirred at room temperature for 24 hours; the mixture is dried in an oven at 80 DEG C until the weight is constant; and the mixture is ground and sieved through a 200 mesh sieve to obtain the attapulgite modified gypsum; the dosages of the pretreated attapulgite, gypsum powder, ethanol and sodium dodecyl benzene sulfonate are 10 g:4 g:50 mL:0.5 g.

[0048] The preparation method of the quick-dissolving mixed fertilizer for improving soil in the embodiment comprises the following steps: urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material are mixed and stirred, water is sprayed into the mixture, the stirring speed is 100 rpm, the stirring time is 60 minutes, the mixture is uniformly mixed, and then granulation is performed to obtain the mixed fertilizer; and the average particle size of the mixed fertilizer is 4 mm.

[0049] Comparative Example 1

[0050] The embodiment provides a quick-dissolving mixed 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 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] The coating material comprises kaolin modified gypsum and wax at a ratio of 5.5:1 by weight.

[0052] The pretreatment of kaolin is as follows: after the kaolin is soaked in 21% sulfuric acid for 22 hours, the kaolin is cleaned with deionized water for three times, and then is dried at 60 DEG C and sieved to obtain the pretreated kaolin with an average particle size of 400 mesh.

[0053] The preparation method of the attapulgite modified gypsum comprises the following steps: mixing and stirring the pretreated kaolin, the gypsum powder with an average particle size of 110 mesh and ethanol, adding sodium dodecyl benzene sulfonate, continuously stirring for 22 hours at room temperature, drying in an oven at 80 DEG C until constant weight, grinding through a 200 mesh sieve, and obtaining the product; the dosage ratio of the pretreated kaolin, the gypsum powder, the ethanol and the sodium dodecyl benzene sulfonate is 10 g: 3.5 g: 55 mL: 0.6 g;

[0054] The preparation method of the modified soil quick-dissolving mixed fertilizer in the embodiment comprises the following steps: mixing and stirring urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, spraying water into the mixture, stirring at a speed of 105 rpm for 50 minutes, uniformly mixing, and granulating to obtain the mixed fertilizer, wherein the average particle size of the mixed fertilizer is 4 mm.

[0055] Comparative Example 2

[0056] The modified soil quick-dissolving mixed fertilizer provided in the embodiment comprises the following raw materials in parts by weight: urea 22 parts, diammonium phosphate 13 parts, potassium sulfate 13 parts, magnesium sulfate 3.5 parts, potassium humate 5.5 parts, lignin 4.5 parts, zinc oxide 0.2 parts, manganese sulfate 0.55 parts, ammonium molybdate 0.7 parts, a coating material 8 parts and water 11 parts.

[0057] The coating material comprises bentonite modified gypsum and wax at a ratio of 5.5:1 by weight.

[0058] The pretreatment of the bentonite comprises the following steps: soaking the bentonite in sulfuric acid with a mass concentration of 21% for 22 hours, washing the bentonite with deionized water for 3 times, drying the bentonite at 60 DEG C, and sieving the dried bentonite to obtain the pretreated bentonite, wherein the average particle size of the pretreated bentonite is 400 mesh.

[0059] The preparation method of the attapulgite modified gypsum comprises the following steps: mixing and stirring the pretreated kaolin, the gypsum powder with an average particle size of 110 mesh and ethanol, adding sodium dodecyl benzene sulfonate, continuously stirring for 22 hours at room temperature, drying in an oven at 80 DEG C until constant weight, grinding through a 200 mesh sieve, and obtaining the product; the dosage ratio of the pretreated kaolin, the gypsum powder, the ethanol and the sodium dodecyl benzene sulfonate is 10 g: 3.5 g: 55 mL: 0.6 g;

[0060] The preparation method of the modified soil quick-dissolving mixed fertilizer in the embodiment comprises the following steps: mixing and stirring urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material, spraying water into the mixture, stirring at a speed of 105 rpm for 50 minutes, uniformly mixing, and granulating to obtain the mixed fertilizer, wherein the average particle size of the mixed fertilizer is 4 mm.

[0061] Comparative Example 3

[0062] The embodiment provides a quick-dissolving soil amendment, 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 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of a coating material and 11 parts of water;

[0063] The coating material comprises gypsum and wax in a weight ratio of 5.5:1.

[0064] The preparation method of the quick-dissolving soil amendment in the embodiment comprises the following steps: the urea, the diammonium phosphate, the potassium sulfate, the magnesium sulfate, the potassium humate, the lignin, the zinc oxide, the manganese sulfate, the ammonium molybdate and the coating material are stirred and mixed, water is sprayed thereon, the stirring speed is 105 rpm, the stirring time is 50 min, and then granulation is performed after uniform mixing to obtain the soil amendment, and the average particle size of the soil amendment is 4 mm.

[0065] Comparative Example 4

[0066] The embodiment provides a quick-dissolving soil amendment, 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 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of a coating material and 11 parts of water;

[0067] The coating material comprises attapulgite and wax in a weight ratio of 5.5:1.

[0068] The preparation method of the quick-dissolving soil amendment in the embodiment comprises the following steps: the urea, the diammonium phosphate, the potassium sulfate, the magnesium sulfate, the potassium humate, the lignin, the zinc oxide, the manganese sulfate, the ammonium molybdate and the coating material are stirred and mixed, water is sprayed thereon, the stirring speed is 105 rpm, the stirring time is 50 min, and then granulation is performed after uniform mixing to obtain the soil amendment, and the average particle size of the soil amendment is 4 mm.

[0069] Comparative Example 5

[0070] The embodiment provides a quick-dissolving soil amendment, 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 parts of zinc oxide, 0.55 parts of manganese sulfate, 0.7 parts of ammonium molybdate, 8 parts of a coating material and 11 parts of water;

[0071] The coating material is wax.

[0072] The preparation method of the instant soil-improving instant mixed fertilizer in the embodiment comprises the following steps: urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material are stirred and mixed, water is sprayed thereon, the stirring speed is 105 rpm, the stirring time is 50 min, and after uniform mixing, granulation is performed to obtain the mixed fertilizer, and the average particle size of the mixed fertilizer is 4 mm.

[0073] Comparative Example 6

[0074] The instant soil-improving instant mixed fertilizer provided in the embodiment comprises the following raw materials in parts by weight: urea 22 parts, diammonium phosphate 13 parts, potassium sulfate 13 parts, magnesium sulfate 3.5 parts, potassium humate 5.5 parts, lignin 4.5 parts, zinc oxide 0.2 parts, manganese sulfate 0.55 parts, ammonium molybdate 0.7 parts, a coating material 8 parts and water 11 parts.

[0075] The coating material is attapulgite modified gypsum.

[0076] The pretreatment of attapulgite comprises the following steps: attapulgite is soaked in 21% sulfuric acid for 22 h, washed with deionized water for 3 times, dried at 60°C and sieved to obtain pretreated attapulgite with an average particle size of 400 mesh.

[0077] The preparation method of the attapulgite modified gypsum comprises the following steps: pretreated attapulgite, gypsum powder with an average particle size of 110 mesh and ethanol are stirred and mixed, sodium dodecyl benzene sulfonate is added and stirred at room temperature for 22 h, dried in an oven at 80°C to constant weight, ground through a 200 mesh sieve to obtain the attapulgite modified gypsum; the amount ratio of the pretreated attapulgite, the gypsum powder, the ethanol and the sodium dodecyl benzene sulfonate is 10 g:3.5 g:55 mL:0.6 g.

[0078] The preparation method of the instant soil-improving instant mixed fertilizer in the embodiment comprises the following steps: urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate and a coating material are stirred and mixed, water is sprayed thereon, the stirring speed is 105 rpm, the stirring time is 50 min, and after uniform mixing, granulation is performed to obtain the mixed fertilizer, and the average particle size of the mixed fertilizer is 4 mm.

[0079] Test Example: The mixed fertilizers prepared in Examples 1-4 and Comparative Examples 1-6 are tested for performance as follows.

[0080] 1. Fertilizer utilization rate: Take 110 tomato seedlings with basically the same growth as the test target crop, and set them into 11 groups, 10 seedlings in each group. The fertilization mode of each group in Examples 1-4 and Comparative Examples 1-6 is as follows: first, dilute the prepared blended fertilizer with 50 times water by weight, to obtain a total amount of 1.5 L of fertilizer and water mixture, and apply it to the soil in each group at one time, fertilize every 10 days, until one week before the fruit is harvested. The blank control group is directly applied with the same amount of water without adding any fertilizer. The average yield per plant is 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 efficiency period: Refer to GB23348-2009 "Slow-release Fertilizer" 28-day cumulative nutrient release rate; the lower the release rate, the longer the fertilizer efficiency 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 examples are only used to illustrate the present application and are not intended to limit the technical solutions described in the present application; those skilled in the art should understand that the present application can still be modified or replaced by equivalents; all technical solutions and improvements that do not deviate from the spirit and scope of the present application should be covered in the scope of the claims of the present application.

Claims

1. A quick-dissolving blended fertilizer for soil improvement, characterized in that, The raw materials include the following parts by weight: 20-25 parts urea, 10-16 parts diammonium phosphate, 12-14 parts potassium sulfate, 3-4 parts magnesium sulfate, 5-6 parts potassium humate, 4-5 parts lignin, 0.1-0.3 parts zinc oxide, 0.5-0.6 parts manganese sulfate, 0.5-1 parts ammonium molybdate, 6-10 parts coating material, and 10-12 parts water; The coating material comprises attapulgite-modified gypsum and wax in a weight ratio of (5-6):1; the preparation method of the attapulgite-modified gypsum includes: mixing and stirring pretreated attapulgite, gypsum powder and ethanol, adding sodium dodecylbenzenesulfonate and stirring at room temperature for 20-24 hours, drying in an oven at 75-85℃ to constant weight, and grinding through a 200-mesh sieve to obtain the attapulgite; 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 with deionized water 2-4 times, drying at 55-65℃, and sieving to obtain the pretreated attapulgite with an average particle size of 300-500 mesh.

2. The quick-dissolving blended fertilizer for soil improvement according to claim 1, characterized in that, The average particle size of the gypsum powder is 100-120 mesh.

3. The quick-dissolving blended fertilizer for soil improvement according to claim 1, characterized in that, The ratio of the pretreated attapulgite, gypsum powder, ethanol and sodium dodecylbenzenesulfonate is (9-11) g: (3-4) g: (50-60) mL: (0.5-0.7) g.

4. A method for preparing a quick-dissolving blended fertilizer for soil improvement as described in any one of claims 1-3, characterized in that the steps... include: Urea, diammonium phosphate, potassium sulfate, magnesium sulfate, potassium humate, lignin, zinc oxide, manganese sulfate, ammonium molybdate, and coating material are stirred and mixed, and water is sprayed into the mixture. After mixing evenly, the mixture is granulated to obtain a blended fertilizer.

5. The method for preparing a quick-dissolving blended fertilizer for soil improvement according to claim 4, wherein the stirring speed is 100-110 rpm and the time is 40-60 min.

6. The method for preparing a quick-dissolving blended fertilizer for soil improvement according to claim 4, characterized in that, The average particle size of the blended fertilizer is 3-5 mm.

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