A controlled-release coated compound fertilizer prepared from distiller's grains

Abstract

A controlled-release coated compound fertilizer prepared from wine lees comprises compound fertilizer particles containing wine lees and a controlled-release coating on the surface, wherein the controlled-release coating is prepared from ethyl cellulose, hydroxypropyl cellulose, glycerol, urea and water to form a controlled-release coating on the surface of the compound fertilizer particles by spraying. The present invention discloses a controlled-release coated compound fertilizer prepared from wine lees, which adopts a core skeleton slow-release combined with a controlled-release coating. After fertilization and watering, the slow-release effect of the skeleton and the slow-release of the coating solve the problem that wine lees compound fertilizer is difficult to achieve slow-release and the slow-release of the coating is difficult to regulate, and the slow release of nutrients in the white wine wine lees compound fertilizer is achieved. The entire release cycle can reach 15 months, which can ensure the entire growth process of the plant. Only one fertilization can achieve the effect of three topdressings in the past, greatly reducing the amount of fertilizer and labor costs.

Description

[0001] The invention patent application number is "202410296042.8", and the invention name is "A composite controlled-release fertilizer made from liquor lees and its preparation method", which is a divisional application. Technical Field

[0002] The invention relates to the technical field of agricultural fertilizer processing, and in particular to a controlled-release coated compound fertilizer prepared from distiller's grains. Background Art

[0003] Slow-release fertilizer is a new type of fertilizer that can continuously release nutrients in the soil and provide long-term and stable nutrient supply for crops. It has better fertilizer durability and utilization rate, can reduce nutrient loss, and improve crop yield and quality. Liquor lees are rich in nutrients and are a natural organic fertilizer. Wine lees fertilizer is rich in various trace elements and nutrients such as nitrogen, phosphorus, and potassium, which increase the resistance of plants, promote plant growth and development, and enhance the ability of plants to adapt to the environment.

[0004] Therefore, if liquor lees can be prepared into controlled-release fertilizers with slow-release function, the fertilizer effect can be prolonged and the nutrient needs of crops throughout the growth cycle can be effectively supplied. Coated slow-release fertilizers are traditional fertilizer particles coated with a slow-release coating. The nutrient slow-release rate is controlled by controlling the coating thickness and material. Due to its slow-release effect, it can ensure that crops get sufficient nutrient supply throughout the growth cycle, effectively avoiding waste and environmental pollution caused by too fast fertilizer release. However, in the process of preparing controlled-release fertilizers with lees as the main fertilizer, it was found that the controlled-release effect of lees fertilizers was not ideal and could not achieve a slow-release controlled-release effect. Summary of the invention

[0005] The invention aims to provide a controlled-release coated compound fertilizer prepared by using liquor lees.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned compound fertilizer using white wine lees. Through the synergistic effect of the fertilizer core and the coating, the effective controlled release of the lees fertilizer is achieved, and the fertilizer effect is prolonged.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A controlled-release coated compound fertilizer prepared by using distiller's grains is characterized in that it comprises compound fertilizer particles and a controlled-release coating on the surface, wherein the controlled-release coating is prepared by coating slurry made of ethyl cellulose, hydroxypropyl cellulose, glycerol, urea and water, and is coated on the surface of the compound fertilizer particles by spraying to form a controlled-release coating, wherein the compound fertilizer particles are placed in a coating pan for rotation preheating, and then the coating slurry is sprayed into the coating pan by a spray gun, and spraying is stopped after the coating weight gain reaches 4-6%, and the coating is continuously rotated until the moisture content of the coating is as low as 5%, the spray gun has a height of 200-250 cm, and a spraying rate of 80-110 mL / min.

[0009] Furthermore, the coating slurry is prepared by mixing 5 to 8 parts of ethyl cellulose, 2 to 3 parts of hydroxypropyl cellulose, 1 to 2 parts of glycerin, and 120 to 150 parts of purified water by weight, heating to a temperature of 40 to 50° C. with stirring, at a stirring speed of 30 to 40 rpm, stirring for 1 to 2 hours, adding 0.6 to 0.8 parts of urea with stirring, continuing to stir until completely dissolved, and cooling to room temperature to obtain the coating slurry.

[0010] Furthermore, the rotary preheating is that the coating pan has a rotation speed of 3.0-5.0 rpm, an inlet air temperature of 60-65° C., and preheating for 10-15 minutes until the surface temperature of the compound fertilizer particles is 35-40° C.

[0011] Furthermore, the preparation of the compound fertilizer particles is to obtain a material by crushing and sieving white wine lees fertilizer, then add hydroxypropyl cellulose and sodium carboxymethyl cellulose, mix at 12-15 rpm for 30-40 minutes to form a mixture, and then extrude and granulate into 0.3-0.5 cm compound fertilizer particles. In parts by weight, the sieved material is 100-120 parts, the hydroxypropyl cellulose is 60-80 parts, and the sodium carboxymethyl cellulose is 200-300 parts.

[0012] Furthermore, the liquor lees fertilizer is prepared into a mixed fermentation material with 500-1000 parts of liquor lees, 30-60 parts of animal manure, 10-12 parts of thiamine, 1.2-1.5 parts of quicklime, and 1-2 parts of organic fermentation bacteria in parts by weight, and purified water is added until the water content of the mixed fermentation material reaches 55-60%, and the materials are piled and fermented to obtain the liquor lees fertilizer. The fermentation is performed by piling the fermentation material into a pile with a height of 1-1.5 m, controlling the fermentation temperature to 40-45° C., fermenting for 25-30 days, then turning the material, controlling the fermentation temperature to 50-55° C., continuing to ferment for 15-20 days, and then drying it to a water content of 5-10% to obtain the liquor lees fertilizer.

[0013] A method for preparing a composite controlled-release fertilizer of liquor lees, characterized in that: fermented liquor lees fertilizer is used to prepare composite fertilizer particles, and a controlled-release coating is coated on the surface of the composite fertilizer particles, specifically, a coating slurry is prepared from ethyl cellulose, hydroxypropyl cellulose, glycerol, urea and water, and is coated on the surface of the composite fertilizer particles by spraying, wherein the liquor lees fertilizer includes liquor lees, animal feces, thiamine and quicklime as raw materials, and is fermented by organic fermentation bacteria. The coating slurry is prepared by mixing 5 to 8 parts of ethyl cellulose, 2 to 3 parts of hydroxypropyl cellulose, 1 to 2 parts of glycerol and 120 to 150 parts of purified water according to weight parts, heating to a temperature of 40 to 50°C under stirring conditions, stirring at a speed of 30 to 40 rpm, stirring for 1 to 2 hours, adding 0.6 to 0.8 parts of urea under stirring conditions, stirring continuously until completely dissolved, and cooling to room temperature to obtain the coating slurry.

[0014] Furthermore, the controlled release coating is prepared by placing the compound fertilizer particles in a coating pan for rotational preheating, and then spraying the coating slurry through a spray gun. When the coating weight gain reaches 4-6%, the spraying is stopped, and the coating is rotated continuously until the moisture content of the coating is as low as 5%.

[0015] Furthermore, the rotary preheating is that the coating pan speed is 3.0-5.0 rpm, the air inlet temperature is 60-65° C., and the preheating is 10-15 minutes until the surface temperature of the compound fertilizer particles is 35-40° C. The spray gun height is 200-250 cm, and the spraying rate is 80-110 mL / min.

[0016] Furthermore, the liquor lees fertilizer is prepared into a mixed fermentation material with 500-1000 parts of liquor lees, 30-60 parts of animal feces, 10-12 parts of thiamine, 1.2-1.5 parts of quicklime, and 1-2 parts of organic fermentation bacteria in parts by weight, and purified water is added until the water content of the mixed fermentation material reaches 55-60%, and the fermentation material is piled into a pile of 1-1.5 m high, the fermentation temperature is controlled at 40-45° C., and the fermentation is carried out for 25-30 days, then the material is turned over, the fermentation temperature is controlled at 50-55° C., and the fermentation is continued for 15-20 days, and then it is dried to a water content of 5-10%, thereby obtaining the liquor lees fertilizer.

[0017] Furthermore, the preparation of the compound fertilizer particles is to obtain a material by crushing and sieving liquor lees fertilizer, wherein the sieving material is 100 to 120 parts by weight, 60 to 80 parts of hydroxypropyl cellulose and 200 to 300 parts of sodium carboxymethyl cellulose are added, and the mixture is mixed at 12 to 15 rpm for 30 to 40 minutes to form a mixture, and then extruded and granulated into compound fertilizer particles of 0.3 to 0.5 cm.

[0018] Hydroxypropyl cellulose is used as a binder to ensure the final formation of compound fertilizer particles. Sodium carboxymethyl cellulose increases the compressibility of the fertilizer and also serves as the skeleton material of the compound fertilizer particles to ensure that the fermented fertilizer has a slow release effect.

[0019] Most specifically, a method for preparing a composite controlled-release fertilizer from liquor lees is characterized by comprising the following steps:

[0020] (1) Fermentation to prepare liquor lees fertilizer

[0021] According to weight parts, 500-1000 parts of liquor lees, 30-60 parts of animal feces, 10-12 parts of thiamine, 1.2-1.5 parts of quicklime, and 1-2 parts of organic fermentation agent are prepared into a mixed fermentation material, purified water is added until the water content of the mixed fermentation material reaches 55-60%, the fermentation material is piled up to 1-1.5m high, the fermentation temperature is controlled at 40-45°C, fermented for 25-30 days, then turned over, the fermentation temperature is controlled at 50-55°C, the fermentation is continued for 15-20 days, the fermentation is stopped, and the fermented material is dried to a water content of 5-10%, thereby obtaining liquor lees fertilizer;

[0022] (2) Preparation of compound fertilizer granules

[0023] The liquor lees fertilizer is crushed and passed through a 50-mesh sieve, hydroxypropyl cellulose and sodium carboxymethyl cellulose are added to the sieved fertilizer, mixed at 12-15 rpm for 30-40 minutes, and taken out to obtain compound fertilizer particles, wherein the sieved fertilizer is 100-120 parts by weight, the hydroxypropyl cellulose is 60-80 parts by weight, and the sodium carboxymethyl cellulose is 200-300 parts by weight;

[0024] (3) Preparation of coating slurry

[0025] According to weight, add 5-8 parts of ethyl cellulose, 2-3 parts of hydroxypropyl cellulose, and 1-2 parts of glycerol to 120-150 parts of purified water, heat to 40-50°C, stir at 30-40 rpm for 1-2 hours, add 0.6-0.8 parts of urea and continue stirring until the urea is completely dissolved, and cool to room temperature to obtain a coating slurry;

[0026] (4) Preparation of controlled release coating

[0027] The compound fertilizer particles prepared in step (2) are placed in a coating pan, and the compound fertilizer particles are rotated and preheated to a surface temperature of 35-40°C at 3.0-5.0 rpm and an inlet air temperature of 60-65°C. The spray gun height is set to 200-250 cm, and the coating slurry is sprayed through the spray gun at a spray rate of 80-110 mL / min. After the coating on the surface of the compound fertilizer particles increases by 4-6%, the spraying is stopped, and the rotation is continued for 10-20 minutes until the moisture content of the coating is less than 5% before discharging.

[0028] After the surface of the compound fertilizer prepared from liquor lees is coated with a controlled-release coating, the lees fertilizer is difficult to be slowly released from the coating, and the controlled-release effect cannot be achieved. If the toughness of the controlled-release coating is reduced, the coating toughness is poor, the fertilizer cannot be completely coated, and it is easy to be damaged, and the controlled-release effect cannot be achieved.

[0029] The present invention introduces glycerol and urea into the coating slurry, effectively improves the toughness of the controlled-release coating in the process of preparing the controlled-release coating by spraying, and promotes the integrity of the controlled-release coating on the compound fertilizer particles. Secondly, in the process of applying the controlled-release fertilizer, a small number of holes are preferentially formed in the controlled-release coating during the initial dissolution of urea in the controlled-release coating in water, and water enters the inside of the coating, so that the skeleton material composed of hydroxypropyl cellulose and sodium carboxymethyl cellulose expands to form a skeleton, which plays a role in the sustained release of the skeleton, so that the components such as thiamine and calcium hydroxide in the compound fertilizer particles are It is slowly released from the pores. Calcium hydroxide releases heat when it meets water, which accelerates the dissolution of urea in the capsule. Since glycerol is hydrophilic, it can be used as a medium, so that when calcium hydroxide penetrates the controlled-release capsule, it forms a cellulose dissolving pore-forming system with the incompletely dissolved urea, thereby increasing the dissolution rate of cellulose in the controlled-release capsule. During the slow-release process, the formation of slow-release channels in the controlled-release capsule is dynamically adjusted, thereby effectively adjusting the controlled-release effect of the controlled-release capsule on the internal fertilizer, slowly releasing it throughout the entire release cycle, and prolonging the fertilizer efficiency of the liquor lees fertilizer.

[0030] The present invention has the following technical effects:

[0031] The controlled-release coated compound fertilizer prepared by the present invention contains organic fertilizers such as white wine lees and animal feces. After fermentation, it contains a large number of microorganisms to form an organic biological compound fertilizer with excellent controlled-release effect, which can continuously and long-term supply crop nutrients, and ensure that the crops are adequately supplied with nutrients throughout the entire growth cycle. The present invention uses the controlled-release coated compound fertilizer prepared from wine lees, adopts a core skeleton slow-release combined with a controlled-release coating, and after fertilizing and watering, through the skeleton slow-release effect and the coating slow-release, the problem that wine lees compound fertilizer is difficult to achieve slow release and the coating slow-release is difficult to regulate is solved, and the slow release of nutrients in the white wine lees compound fertilizer is achieved. The entire release cycle can reach 15 months, which can ensure that the entire growth process of the plant can achieve the effect of three topdressings in the past with only one fertilizer application, greatly reducing the amount of fertilizer and labor costs. DETAILED DESCRIPTION

[0032] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-mentioned contents of the present invention.

[0033] Example 1

[0034] A controlled-release coated compound fertilizer prepared from distiller's grains is prepared according to the following steps:

[0035] (1) Fermentation to prepare liquor lees fertilizer

[0036] According to weight parts, 800 parts of corn liquor lees, 50 parts of chicken manure, 10 parts of thiamine, 1.5 parts of quicklime, and 1.5 parts of organic fermentation agent are prepared into a mixed fermentation material, purified water is added until the water content of the mixed fermentation material reaches 55-60%, the fermentation material is piled up to 1-1.5m high, the fermentation temperature is controlled at 40-45°C, fermented for 28 days, then turned over, the fermentation temperature is controlled at 50°C, the fermentation is continued for 18 days, the fermentation is stopped, and the fermented material is dried to a water content of 5-10%, thereby obtaining liquor lees fertilizer;

[0037] (2) Preparation of compound fertilizer granules

[0038] The liquor lees fertilizer was crushed and passed through a 50-mesh sieve, hydroxypropyl cellulose and sodium carboxymethyl cellulose were added to the sieved fertilizer, and mixed at 13 rpm for 35 minutes, and then taken out to obtain compound fertilizer particles, wherein the sieved fertilizer was 110 parts by weight, the hydroxypropyl cellulose was 70 parts by weight, and the sodium carboxymethyl cellulose was 250 parts by weight;

[0039] (3) Preparation of coating slurry

[0040] According to weight, 6 parts of ethyl cellulose, 2.5 parts of hydroxypropyl cellulose, and 1.5 parts of glycerol are added to 130 parts of purified water, heated to 45°C, stirred at 35 rpm for 1.5 hours, and then 0.7 parts of urea are added and stirred until the urea is completely dissolved, and then cooled to room temperature to obtain a coating slurry;

[0041] (4) Preparation of controlled release coating

[0042] The compound fertilizer particles prepared in step (2) are placed in a coating pan, and the compound fertilizer particles are rotated and preheated to a surface temperature of 40°C at 4.0 rpm and an inlet air temperature of 60°C. The spray gun height is set to 220 cm, and the coating slurry is sprayed through the spray gun at a spray rate of 100 mL / min. After the coating on the surface of the compound fertilizer particles increases by 5%, the spraying is stopped, and the rotation is continued for 15 minutes until the moisture content of the coating is less than 5%, and then the material is discharged to obtain a controlled-release coated compound fertilizer.

[0043] Comparative Example 1

[0044] Compared with Example 1, no glycerol was added when preparing the coating, and the remaining steps were the same as Example 1.

[0045] Comparative Example 2

[0046] Compared with Example 2, when preparing the coating, urea was replaced with polyvinyl alcohol that can achieve pore formation, and the remaining steps were the same as those in Example 2.

[0047] When preparing the coating, attempts were also made to add alkali to the coating slurry to directly form a pore-forming system in the controlled-release coating. However, the coating effect obtained was very poor and it was basically impossible to completely encapsulate the compound fertilizer particles.

[0048] Example 2

[0049] A controlled-release coated compound fertilizer prepared from distiller's grains is prepared according to the following steps:

[0050] (1) Fermentation to prepare liquor lees fertilizer

[0051] According to weight parts, 500 parts of sorghum liquor lees, 30 parts of cow dung, 10 parts of thiamine, 1.5 parts of quicklime, and 2 parts of organic fermentation agent are prepared into a mixed fermentation material, purified water is added until the water content of the mixed fermentation material reaches 55-60%, the fermentation material is piled to a height of 1-1.5m, the fermentation temperature is controlled at 40-45°C, fermented for 25 days, then turned over, the fermentation temperature is controlled at 50-55°C, the fermentation is continued for 20 days, the fermentation is stopped, and the fermented material is dried to a water content of 5-10%, thereby obtaining liquor lees fertilizer;

[0052] (2) Preparation of compound fertilizer granules

[0053] The liquor lees fertilizer was crushed and passed through a 50-mesh sieve, hydroxypropyl cellulose and sodium carboxymethyl cellulose were added to the sieved fertilizer, mixed at 15 rpm for 30 minutes, and taken out to obtain compound fertilizer particles, wherein the sieved fertilizer is 100 parts, the hydroxypropyl cellulose is 60 parts, and the sodium carboxymethyl cellulose is 200 parts by weight;

[0054] (3) Preparation of coating slurry

[0055] According to weight, 5 parts of ethyl cellulose, 2 parts of hydroxypropyl cellulose, and 1 part of glycerol are added to 120 parts of purified water, heated to 50°C, stirred at 30 rpm for 2 hours, and then 0.6 parts of urea are added and stirred until the urea is completely dissolved, and then cooled to room temperature to obtain a coating slurry;

[0056] (4) Preparation of controlled release coating

[0057] The compound fertilizer particles prepared in step (2) are placed in a coating pan, and the compound fertilizer particles are rotated and preheated to a surface temperature of 35°C at 3.0 rpm and an inlet air temperature of 65°C. The spray gun height is set to 200 cm, and the coating slurry is sprayed through the spray gun at a spray rate of 80 mL / min. After the coating on the surface of the compound fertilizer particles increases by 6%, the spraying is stopped, and the rotation is continued for 10 minutes until the moisture content of the coating is less than 5%, and then the material is discharged to obtain a controlled-release coated compound fertilizer.

[0058] Example 3

[0059] A controlled-release coated compound fertilizer prepared using distiller's grains is prepared according to the following steps:

[0060] (1) Fermentation to prepare liquor lees fertilizer

[0061] According to weight parts, 1000 parts of glutinous rice liquor lees, 60 parts of cow dung, 12 parts of thiamine, 1.2 parts of quicklime, and 1 part of organic fermentation agent are prepared into a mixed fermentation material, purified water is added until the water content of the mixed fermentation material reaches 55-60%, the fermentation material is piled up to 1-1.5m high, the fermentation temperature is controlled at 40-45°C, fermented for 30 days, then turned over, the fermentation temperature is controlled at 50-55°C, the fermentation is continued for 15 days, the fermentation is stopped, and the fermented material is dried to a water content of 5-10%, thereby obtaining liquor lees fertilizer;

[0062] (2) Preparation of compound fertilizer granules

[0063] The liquor lees fertilizer was crushed and passed through a 50-mesh sieve, hydroxypropyl cellulose and sodium carboxymethyl cellulose were added to the sieved fertilizer, mixed at 12 rpm for 40 minutes, and taken out to obtain compound fertilizer particles, wherein the sieved fertilizer was 120 parts by weight, the hydroxypropyl cellulose was 80 parts by weight, and the sodium carboxymethyl cellulose was 300 parts by weight;

[0064] (3) Preparation of coating slurry

[0065] According to weight, 8 parts of ethyl cellulose, 3 parts of hydroxypropyl cellulose, and 2 parts of glycerol are added to 150 parts of purified water, heated to 40°C, stirred at 40 rpm for 1 hour, and then 0.8 parts of urea are added and stirred until the urea is completely dissolved, and then cooled to room temperature to obtain a coating slurry;

[0066] (4) Preparation of controlled release coating

[0067] The compound fertilizer particles prepared in step (2) are placed in a coating pan, and the compound fertilizer particles are rotated and preheated to a surface temperature of 40°C at 5.0 rpm and an inlet air temperature of 60°C. The spray gun height is set to 200 cm, and the coating slurry is sprayed through the spray gun at a spray rate of 110 mL / min. After the coating on the surface of the compound fertilizer particles increases by 4%, the spraying is stopped, and the rotation is continued for 20 minutes until the moisture content of the coating is less than 5%, and then the material is discharged to obtain a controlled-release coated compound fertilizer.

[0068] The organic fermentation agent used in the present invention is YJF193, which was purchased from Shijiazhuang Fuming Bio-Organic Fertilizer Co., Ltd. The agent contains a variety of microorganisms commonly used in fermentation. The function of the organic fermentation agent is to ferment raw materials such as wine lees. Therefore, other types of organic fermentation agents can be used as long as they can achieve the fermentation effect.

[0069] The controlled-release coated compound fertilizers with complete particles prepared in each embodiment, comparative example 1 and comparative example 2 were selected, 10.0 g of each was weighed, and placed in a container containing 100 mL of deionized water, respectively, and allowed to stand at 25°C for dissolution, and samples were taken at intervals, and repeated 3 times; 5 mL was sampled each time, and an equal amount of deionized water was added again to continue dissolution. The conductivity value of the sample was measured to characterize the cumulative nutrient release rate. The results are shown in Table 1.

[0070] Table 1:

[0071]

[0072] It can be seen that the nutrient accumulation and release rate in Comparative Example 1 is extremely fast, and the nutrients are completely released in water in just 15 days. However, in Comparative Example 2, since there is no adjustment to form a good slow-release channel, it is difficult for the compound fertilizer based on corn liquor lees to release nutrients. In each embodiment of the present invention, calcium hydroxide in the compound fertilizer particles and urea in the coating form a good pore-forming system under the action of glycerol, which effectively adjusts the slow-release channel on the coating, so that the nutrients in the compound fertilizer are effectively controlled and released.

[0073] The controlled-release coated compound fertilizer prepared in Example 1 of the present invention was placed in the soil, and the controlled-release performance of the fertilizer was measured by detecting the change in mass of the compound controlled-release fertilizer in the soil. During the detection process, the soil moisture was kept constant at 25%. The results showed that the release period of the compound fertilizer prepared in Example 1 could be as long as 15 months. The release period of the compound fertilizer in Comparative Example 1 was about two months, and the release amount of Comparative Example 2 was only 44.6% at 15 months.

[0074] Field trials:

[0075] The same tomato planting site was divided into 4 large blocks, and Example 1, Comparative Example 1, Comparative Example 2 and CK group fertilizers were applied respectively. The CK group was a compound fertilizer prepared in the manner of Example 1 and an equal amount of urea as the coating of Example 1. ① After the crop was planted, water was poured thoroughly, and after 4-5 days, water was poured once to slow down the seedlings, and then no watering was required until the fruit was set. ② After the first ear of fruit was set, watering was restarted, and the water content in the soil was kept at 70-80% before watering was stopped. The planting plots corresponding to the CK group were divided into 4 small blocks, corresponding to the number of fertilizations of 0, 1, 2 and 3 times, respectively. Among them, fertilization was applied once after the first ear of fruit was set, and when the second and third ears of fruit began to swell, each was re-fertilized once. The amount of fertilizer applied each time was 30g / plant. The final yield of tomatoes is shown in Table 2.

[0076] Table 2: Effects of different compound fertilizers on crop yields

[0077]

[0078] Without applying any fertilizer after fruit setting, the tomato yield was about 2300 kg / mu. After fruit setting, the CK group applied fertilizer granules prepared from white wine lees and urea composite, and the yield reached 2866 kg / mu. When the controlled-release coated compound fertilizer prepared in Example 1 of the present invention was applied, the tomato yield was 3392 kg / mu. The tomato yields of the corresponding composite controlled-release fertilizers of Comparative Examples 1 and 2 were 2962 kg / mu and 2579 kg / mu, respectively.

[0079] The fertilizer of group CK was used, and fertilizer was applied once after the first bunch of fruits set, and when the second and third bunches of fruits began to expand, topdressing was applied once each. The final tomato yield after three fertilizations was 3427 kg / mu, which was equivalent to the yield of one fertilization in Example 1.

Claims

1. A controlled-release coated compound fertilizer prepared using distiller's grains, characterized in that: The invention comprises compound fertilizer particles and a controlled-release coating on the surface. The controlled-release coating is prepared by coating slurry made of ethyl cellulose, hydroxypropyl cellulose, glycerol, urea and water, and is coated on the surface of the compound fertilizer particles by spraying to form a controlled-release coating. Specifically, the compound fertilizer particles are placed in a coating pan for rotation preheating, and then the coating slurry is sprayed into the coating slurry through a spray gun. After the coating weight gain reaches 4-6%, the spraying is stopped, and the coating is rotated continuously until the moisture content of the coating is as low as 5%. The height of the spray gun is 200-250 cm, and the spraying rate is 80-110 mL / min. The coating slurry is prepared by mixing 5-8 parts of ethyl cellulose, 2-3 parts of hydroxypropyl cellulose, 1-2 parts of glycerol and 120-150 parts of purified water according to weight. , under stirring conditions, heat to a temperature of 40-50°C, a stirring speed of 30-40rpm, and stir for 1-2h. Under stirring conditions, add 0.6-0.8 parts of urea, continue stirring until completely dissolved, and cool to room temperature to obtain a coating slurry. The compound fertilizer particles are obtained by crushing and sieving white wine lees fertilizer, and then adding hydroxypropyl cellulose and sodium carboxymethyl cellulose. Mix at 12-15rpm for 30-40min to form a mixture, and then extruding and granulating into 0.3-0.5cm compound fertilizer particles. According to weight parts, the sieved material is 100-120 parts, hydroxypropyl cellulose is 60-80 parts, and sodium carboxymethyl cellulose is 200-300 parts.

2. The controlled-release coated compound fertilizer prepared using distiller's grains as claimed in claim 1, characterized in that: The rotary preheating is that the coating pan has a rotation speed of 3.0-5.0 rpm, an air inlet temperature of 60-65° C., and is preheated for 10-15 minutes until the surface temperature of the compound fertilizer particles reaches 35-40° C.

3. A controlled-release coated compound fertilizer prepared using distiller's grains as claimed in claim 1 or 2, characterized in that: The liquor lees fertilizer is prepared into a mixed fermentation material with 500-1000 parts of liquor lees, 30-60 parts of animal manure, 10-12 parts of thiamine, 1.2-1.5 parts of quicklime and 1-2 parts of organic fermentation bacteria in parts by weight, and purified water is added until the water content of the mixed fermentation material reaches 55-60%, and the materials are piled and fermented to obtain the liquor lees fertilizer. The fermentation is to pile the fermentation material into a pile of 1-1.5m high, control the fermentation temperature to 40-45°C, ferment for 25-30 days, then turn the material, control the fermentation temperature to 50-55°C, continue to ferment for 15-20 days, and then dry it to a water content of 5-10% to obtain the liquor lees fertilizer.

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