CN106977277A - Potassium polyphosphate corn slow-release fertilizer and production method thereof - Google Patents

Abstract

The invention relates to a potassium polyphosphate corn slow release fertilizer and a production method thereof, wherein the fertilizer comprises the following raw materials in parts by weight: 55-65 parts of urea; 45-50 parts of potassium polyphosphate; 10-15 parts of diammonium hydrogen phosphate; 0.5-0.8 part of magnesium sulfate; 0.4-0.6 part of calcium nitrate; 1.5-2.0 parts of trace elements; 8-10 parts of bone meal; 5-10 parts of humic acid; 10-15 parts of decomposed cow dung; 4-6 parts of derris elliptica; 10-15 parts of a slow release agent. The potassium polyphosphate corn slow-release fertilizer produced by the invention is prepared according to the fertilizer requirement characteristics of corn growth, and the produced potassium polyphosphate corn slow-release fertilizer is rich and balanced in nutrition, rich in various nutrients and medium and trace elements, can quickly and long-acting supplement nutrients required by corn, can slowly release nutrient components in the fertilizer, has long fertilizer effect, is beneficial to improving the utilization rate of the fertilizer, and plays a role in increasing both production and income and improving the quality of corn.

Description

Potassium polyphosphate corn slow-release fertilizer and production method thereof

technical field

The invention relates to a fertilizer, in particular to a potassium polyphosphate slow-release fertilizer for corn and a production method thereof, belonging to the technical field of fertilizer production.

Background technique

Corn (scientific name: Zea mays), also known as corn, corn, corn, cob; is an annual grass herb, an important food crop and an important source of feed. The history of corn cultivation in my country is about 470 years. At present, my country's sown area is about 300 million mu, second only to rice and wheat, ranking third among food crops, and second only to the United States in the world. Corn is planted all over China, especially in the Northeast, North and Southwest provinces. Corn is a good health product in coarse grains, and eating corn is quite beneficial to human health. According to research, every 100 grams of corn contains 106 kcal of calories, 2.9 grams of cellulose, 4.0 grams of protein, 1.2 grams of fat, 22.8 grams of carbohydrates, and other mineral elements and vitamins. The crude fiber contained in corn is 4-10 times higher than that of polished rice and refined noodles. Corn also contains a lot of magnesium, which can strengthen the peristalsis of the intestinal wall and promote the excretion of waste from the body. Corn is an important food crop in China. Corn plays an extremely important role in my country's food security. It is an important feed crop and an important raw material for food, chemical, fuel, and pharmaceutical industries. Therefore, its importance has been highlighted.

Corn is an important economic crop in my country. Fertilizers need to be applied during the planting process of corn, and the input of fertilizer plays a vital role in the yield of corn. In modern corn agriculture, artificial fertilization has become an important measure for corn production and high-yield cultivation. However, in the actual planting process of corn, there have been problems of single and excessive fertilization for a long time, and the average utilization rate of fertilizers is very low. The main reason is that fertilizers are quick-acting and volatile and easy to lose. In the process of planting corn, multiple fertilization is often required to meet the nutrients required for corn production, but multiple fertilization is labor-intensive, time-consuming and labor-intensive, and is no longer suitable for the development of the modern corn industry.

Slow-release fertilizers have the advantages of reduced fertilizer consumption, improved utilization, convenient application, labor-saving and safety, etc. The invention and solution of slow-release fertilizers has opened up new ideas and more effective ways for the above problems. The direction of sustainable development of the fertilizer industry. And aspect the used slow-release fertilizer of corn, people also constantly carry out research, retrieve related documents such as: the application number is that the Chinese patent of 200710080227.1 discloses a kind of slow-release fertilizer special for corn, this special slow-release fertilizer for corn is taken 0.1 %-0.3% hydroquinone wrapped urea, granular general calcium (containing P2O5 14%), granular potassium sulfate (containing K2O33%), zinc sulfate, and 2.5% polyvinyl alcohol are mixed and packaged with slow-release capsules to make corn special Slow-release fertilizer; the beneficial effects of the invention are: the base fertilizer can be applied to the film-covered corn at one time, no need to apply fertilizer in the middle growth period, there is no "burning seedling" phenomenon, the film will not be damaged by fertilization, and it can meet the needs of corn growth. Compared with conventional fertilizers with the same amount of nutrients, it can increase the yield by 14-17%. It can save 2 manpower for top dressing per mu of land, and save 20 yuan/mu. As another example, the Chinese patent application number 200710114213.7 discloses a special controlled-release fertilizer for corn and its preparation method. According to the fertilizer requirement of corn, 5% and 6% of thermoplastic resin-coated urea, sulfur-coated urea and Potassium chloride compound fertilizer, potassium chloride, large particle urea and zinc sulfate are precisely compounded to form a special formula controlled release fertilizer for corn. The nutrient release law of the controlled-release fertilizer is consistent with the nutrient absorption law of the corn, and the cost of the controlled-release fertilizer is reduced. The controlled-release fertilizer is used to fertilize the corn before planting, and there will be no topdressing in the future, which reduces the labor intensity and labor of farmers. cost.

At present, slow-release fertilizer has become the direction of sustainable development of the fertilizer industry in various countries in the world. There are two kinds of slow-release fertilizers: organic synthetic slow-release fertilizer and coated slow-release fertilizer. Among them, the coated slow-release fertilizer has excellent controllable slow-release performance, and has always been the key direction and main task of slow-release fertilizer research and development. . However, the coating materials currently used for coated slow-release fertilizers are usually non-fertilizer polymers, which have low effective fertilizer content, high product costs, and high prices of non-fertilizer polymers, which eventually lead to low yields of corn and will also affect the soil. The environment poses risks. At present, there are still the following problems in corn planting: First, slow-release fertilizers are not highly targeted, and the nitrogen, potassium, phosphorus and other minerals required by different crops are not the same, and the selection of slow-release fertilizers that are not highly targeted will easily cause waste and waste. Soil pollution is not conducive to increasing production; second, due to the influence of membrane materials and production process costs, the price of slow-release fertilizers is high, which limits its promotion and application; third, the selected coating materials are inappropriate, which will damage the soil structure .

Contents of the invention

The object of the present invention is to provide a kind of potassium polyphosphate corn slow-release fertilizer and production method thereof, this potassium polyphosphate corn slow-release fertilizer is prepared according to the characteristics of the fertilizer needed for corn growth, and can provide the required amount of fertilizer for corn growth. A variety of nutrient elements, and the nutrient components in the fertilizer can be released slowly, and the fertilizer effect is long-lasting, which is conducive to improving the utilization rate of the fertilizer, increasing production and income, and improving the quality of corn.

To achieve the above object, the present invention adopts the following technical solutions:

A potassium polyphosphate slow-release fertilizer for corn, comprising the following raw materials in parts by weight:

55-65 parts of urea; 45-50 parts of potassium polyphosphate; 10-15 parts of diammonium hydrogen phosphate; 0.5-0.8 parts of magnesium sulfate; 0.4-0.6 parts of calcium nitrate; 1.5-2.0 parts of trace elements; 8-10 parts of bone meal ; 5-10 parts of humic acid;

10-15 parts of decomposed cow dung; 4-6 parts of deervine; 10-15 parts of sustained release agent; described trace elements and weight ratio are Fe:Mn:Zn:Cu:B:Mo=3:2:3: 2:2:0.8.

The production method of described potassium polyphosphate corn slow release fertilizer is:

(1) Add magnesium sulfate, calcium nitrate and trace elements to potassium polyphosphate according to parts by weight, mix and stir for 15-20 minutes to obtain mixture A;

(2) Mix bone meal, decomposed cow dung, humic acid and deervine to obtain mixture B, then fully mix mixture A and mixture B, and finally add urea and diammonium hydrogen phosphate and mix evenly to obtain mixture C;

(3) The mixture C is pulverized by an automatic feeding system, fully mixed evenly, and granulated according to the drum granulation method to obtain granules. The outer layer of the granules is coated with a sustained-release agent and dried to obtain the product.

Above-mentioned potassium polyphosphate corn slow-release fertilizer, the preparation method of described potassium polyphosphate comprises the following steps:

① Put yellow phosphorus in a combustion furnace and burn it at 500-700°C to get P ₂ O ₅ gas;

②Use a fan to pump the P ₂ O ₅ gas into the polymerization tower, continuously pour water to dissolve the P ₂ O ₅ gas into the water, until the weight concentration of P ₂ O ₅ in the solution reaches 72-87%, and obtain a solution;

3. in the solution that obtains, according to hydrogen sulfide gas: solution is 1:1000～2000 weight ratio hydrogen sulfide gas is passed in the solution, reaction generates arsenic sulfide solid, filters, and the arsenic content in the detection solution drops below 1PPM, The content of heavy metals is reduced to below 30 PPM to obtain polyphosphoric acid;

④ Slowly add the obtained polyphosphoric acid into the potassium hydroxide solution with a mass fraction of more than 65%, strictly control the reaction temperature between 15-45°C, stir while adding, react for 120-180 minutes, and detect The weight percentage of K ₂ O and P ₂ O ₅ in the product, the content of K ₂ O in the product is 33%, the content of P ₂ O ₅ is 10%, the reaction is completed, and potassium polyphosphate is prepared.

Above-mentioned potassium polyphosphate corn slow-release fertilizer, the preparation method of described slow-release agent is: according to polyvinyl alcohol: beta-cyclodextrin: water is the weight ratio of 2-3:4-5:75-85, Dissolving polyvinyl alcohol in hot water at 65-75°C, stirring for 4-5 minutes, then adding β-cyclodextrin, stirring and dissolving, and mixing uniformly to prepare the slow-release agent.

In the present invention, the bone meal used is the bone meal of animals such as pigs, cattle, sheep, etc., which contains rich nutrients, except calcium 20% ~ 30%, phosphorus 8% ~ 14%, also contains Mg, K, Na, Ba, Trace elements such as Co, Cu, Fe, Mo, Ni, Ti, V, Zn, Sr, and a complete range of amino acids (18 types); bone meal is a good slow-acting phosphate fertilizer, which can provide the phosphorus needed for growth of crops Elements, improve fertilizer efficiency, and adding bone meal to fertilizer is very beneficial to improving acidic soil and promoting crop growth.

The said fish vine (Derristrifoliata Lour.) belongs to leguminous vines, climbing shrubs, all bald. Rotenone, rotenone, edamame, and poison ash leaf phenol are the main components of rotenone root. It can be made into powder and emulsion, which can be mixed with sulfur mixture, pyrethrum emulsion, etc. It mainly acts as a contact killer on insects, and also has the effect of stomach poison and repellent. Its toxicity is mainly to paralyze the respiratory center and The vasomotor nerve center has curative effects on aphids, lepidopteran larvae, beetle larvae, dog fleas, and cattle flies, and can be used to treat human scabies. Rotenone has a wide insecticidal spectrum and can control more than 800 kinds of pests. It is one of the three traditional insecticidal plants. The deervine used in the present invention is obtained by washing and chopping the whole deervine plant, drying and crushing, and preparing fertilizer by using the deervine, which can prevent and control crop diseases and insect pests, and can also have a significant effect on weeding. Adding deervine in the present invention can play the role of pest repellant, thereby improving the insect pest resistance ability of corn.

The beneficial effects of the present invention are:

1, the preparation method of ammonium polyphosphate of the present invention is unique, has no report, and the self-made potassium polyphosphate of the present invention has high nutrient content, good solubility, and is not easy to react with calcium, magnesium, iron, aluminum etc. Potassium polyphosphate is a fast and long-lasting fertilizer that can provide the crops with the required phosphorus and potassium elements. Potassium polyphosphate is easily absorbed by crops. The self-made potassium polyphosphate of the present invention has stable properties at normal temperature, no precipitation after being placed at normal temperature for 3 months, and is convenient for transportation and use. But the production of potassium polyphosphate is not easy to control, the present invention prepares potassium polyphosphate, the order of material addition must be that polyphosphoric acid is added dropwise in potassium hydroxide, because polyphosphoric acid viscosity is very big and reaction can emit a large amount of heat , If potassium hydroxide is added dropwise to polyphosphoric acid, the heat of reaction is difficult to transfer to the cooling device, and it is easy to cause the local temperature to be too high to cause the generated potassium polyphosphate to hydrolyze and fail. Moreover, the concentration of potassium hydroxide used must be above 65%, otherwise there is too much moisture in the product, and the required K ₂ O and P ₂ O ₅ contents cannot be obtained. The present invention prepares potassium polyphosphate corn slow-release fertilizer firstly to prepare potassium polyphosphate, and the potassium polyphosphate produced by this process has a moderate degree of polymerization, which contains about 50% potassium orthophosphate and about 45% potassium dipolyphosphate. The rest is phosphate with a higher degree of polymerization. In such a ratio, it is not easy to precipitate potassium polyphosphate crystals, and the phosphorus element can be released slowly for a long time. Potassium polyphosphate is easily absorbed by crops and is used to prepare potassium polyphosphate corn. Slow-release fertilizer, the nutrient elements in the fertilizer can be released slowly, and the corn can quickly and long-term absorb the nutrient elements, with high utilization rate, and the made corn slow-release fertilizer has good and long-lasting fertilizer effect.

2. The used deervine of the potassium polyphosphate corn slow-release fertilizer prepared by the present invention is a kind of botanical insecticide, which is pollution-free and has a good effect of deworming and killing insects. By adding deervine in the fertilizer and then Applying it to the corn field can improve the disease resistance and pest resistance of the corn.

3, the trace element that the present invention adds contains elements such as Fe, Mn, Zn, B, can provide required trace element for corn, and the self-made potassium polyphosphate of the present invention itself is a kind of inorganic polymer fertilizer, not only can Provide corn with the required long-lasting potassium source and phosphorus source; and add magnesium sulfate, calcium nitrate and trace elements to potassium polyphosphate to stir and react. Potassium polyphosphate has the effect of chelating metal ions, which can improve The activity of trace elements such as calcium and manganese, the chelated trace elements formed after the reaction are more easily absorbed by plants, which greatly improves the absorption efficiency of corn to trace elements. The potassium polyphosphate added in the invention not only does not reduce the fertilizer efficiency of the medium and trace elements, but also improves the activity of the medium and trace elements and improves the fertilizer efficiency.

4. The sustained-release agent used in the present invention is prepared from polyvinyl alcohol, β-cyclodextrin and water. The β-cyclodextrin used is safe and environmentally friendly, and will not pollute the environment. By wrapping a layer of slow-release agent on the outer layer of the manufactured fertilizer granules, the slow-release effect of the fertilizer can be improved, the nutrients in the fertilizer can be released slowly, and the utilization rate of the fertilizer can be improved.

5. The potassium polyphosphate corn slow-release fertilizer prepared by the present invention has the function of slow release in itself, and the slow-release agent is added to the fertilizer, which can control the release speed of the fertilizer and greatly improve the yield of the fertilizer. utilization rate.

6. The potassium polyphosphate corn slow-release fertilizer produced by the present invention is prepared according to the characteristics of corn growth. The produced potassium polyphosphate corn slow-release fertilizer is rich in nutrients and balanced, rich in various nutrients and trace elements , can quickly and long-term supplement the nutrients needed by corn, and the nutrients in the fertilizer can be released slowly, and the fertilizer effect is long-lasting, which is conducive to improving the utilization rate of fertilizers, increasing production and income, and improving the quality of corn.

6. The applicant is a manufacturer of polyphosphoric acid for many years. It has been committed to the research of agricultural fertilizers for several years. It has also carried out fertilization pilot tests and field tests on various crops. In particular, it has seen the inorganic nitrogen, phosphorus and potassium currently used by farmers Fertilizers contain less organic matter, long-term use will make the soil harden, the growth of plants will become worse and worse, and the pests and diseases will become more and more serious. Although some fertilizers can increase the production of sugarcane, their sugar content is not high and the quality is not good, so new fertilizers are used. The ammonium polyphosphate production method makes the absorption of fertilizer by sugarcane tend to be in the direction of organic fertilizer, with high sugar content. Several fertilizer patents filed by the applicant on the same day are a series of products based on polyphosphoric acid to adapt to different crop fertilizers, not the pursuit of quantity for the purpose of patent application.

detailed description

Example 1

A potassium polyphosphate slow-release fertilizer for corn, comprising the following raw materials in parts by weight:

55 parts of urea; 45 parts of potassium polyphosphate; 10 parts of diammonium hydrogen phosphate; 0.5 parts of magnesium sulfate; 0.4 parts of calcium nitrate; 1.5 parts of trace elements; 8 parts of bone meal; 5 parts of humic acid; 4 parts; 10 parts of slow-release agent; described trace element and weight ratio are Fe:Mn:Zn:Cu:B:Mo=3:2:3:2:2:0.8.

The preparation method of described potassium polyphosphate comprises the following steps:

① Put yellow phosphorus in a combustion furnace and burn it at 500°C to get P ₂ O ₅ gas;

②Use a fan to pump P ₂ O ₅ gas into the polymerization tower, continuously pour water to dissolve P ₂ O ₅ gas into water, until the weight concentration of P ₂ O ₅ in the solution reaches 72%, and obtain a solution;

3. in the solution obtained, according to hydrogen sulfide gas: solution is 1:1000 weight ratio hydrogen sulfide gas is passed in the solution, reaction generates arsenic sulfide solid, filters, and the arsenic content in the detection solution drops below 1PPM, the content of heavy metal The content drops below 30 PPM to obtain polyphosphoric acid;

④ Slowly add the obtained polyphosphoric acid into the potassium hydroxide solution with a mass fraction of 65% or more, strictly control the reaction temperature to 15°C, stir while adding, react for 180 minutes, and detect K ₂ O and The weight percentage of P ₂ O ₅ , the content of K ₂ O in the product to be prepared is 33%, the content of P ₂ O ₅ is 10%, and the reaction is completed to prepare potassium polyphosphate.

The preparation method of the sustained-release agent is as follows: according to the weight ratio of polyvinyl alcohol: β-cyclodextrin: water is 2:4:75, first dissolve polyvinyl alcohol into hot water at 65°C, and stir for 5 minutes , and then add β-cyclodextrin, stir to dissolve, and mix evenly to prepare a sustained-release preparation.

The production method of described potassium polyphosphate corn slow release fertilizer is:

(1) Add magnesium sulfate, calcium nitrate and trace elements to potassium polyphosphate according to parts by weight, mix and stir for 15 minutes to obtain mixture A;

(2) Mix bone meal, decomposed cow dung, humic acid and deervine to obtain mixture B, then fully mix mixture A and mixture B, and finally add urea and diammonium hydrogen phosphate and mix evenly to obtain mixture C;

(3) The mixture C is pulverized by an automatic feeding system, fully mixed evenly, and granulated according to the drum granulation method to obtain granules. The outer layer of the granules is coated with a sustained-release agent and dried to obtain the product.

Example 2

A potassium polyphosphate slow-release fertilizer for corn, comprising the following raw materials in parts by weight:

60 parts of urea; 48 parts of potassium polyphosphate; 12 parts of diammonium hydrogen phosphate; 0.6 parts of magnesium sulfate; 0.5 parts of calcium nitrate; 1.8 parts of trace elements; 9 parts of bone meal; 7 parts of humic acid; 5 parts; 12 parts of sustained-release agent; described trace element and weight ratio are Fe:Mn:Zn:Cu:B:Mo=3:2:3:2:2:0.8.

The preparation method of described potassium polyphosphate comprises the following steps:

① Put yellow phosphorus in a combustion furnace and burn it at 600°C to get P ₂ O ₅ gas;

②Use a fan to pump the P ₂ O ₅ gas into the polymerization tower, and continuously pour water to dissolve the P ₂ O ₅ gas into the water until the weight concentration of P ₂ O ₅ in the solution reaches 81%, and a solution is obtained;

3. in the solution obtained, according to hydrogen sulfide gas: solution is that hydrogen sulfide gas is passed in the solution in the weight ratio of 1:1600, reacts and generates arsenic sulfide solid, filters, and the arsenic content in the detection solution drops below 1PPM, the content of heavy metal content drops below 30 PPM to obtain polyphosphoric acid; if it is detected that the arsenic content in the solution and the content of heavy metals do not meet the above requirements, hydrogen sulfide gas is introduced into the solution again until the arsenic content in the solution and the content of heavy metals reach the above requirements;

④ Slowly add the obtained polyphosphoric acid into the potassium hydroxide solution with a mass fraction of 75%, strictly control the reaction temperature at 25°C, stir while adding, react for 150 minutes, and detect K ₂ O and P in the product ₂ O ₅ weight percent content, the content of K ₂ O in the product is 33%, the content of P ₂ O ₅ is 10%, the reaction is completed, and potassium polyphosphate is prepared.

The preparation method of the slow-release agent is as follows: according to the weight ratio of polyvinyl alcohol: β-cyclodextrin: water is 2.5:4.5:80, first dissolve polyvinyl alcohol into hot water at 70°C, and stir for 4 minutes , and then add β-cyclodextrin, stir to dissolve, and mix evenly to prepare a sustained-release preparation.

The production method of described potassium polyphosphate corn slow release fertilizer is:

(1) Add magnesium sulfate, calcium nitrate and trace elements to potassium polyphosphate according to parts by weight, mix and stir for 18 minutes to obtain mixture A;

(2) Mix bone meal, decomposed cow dung, humic acid and deervine to obtain mixture B, then fully mix mixture A and mixture B, and finally add urea and diammonium hydrogen phosphate and mix evenly to obtain mixture C;

(3) The mixture C is pulverized by an automatic feeding system, fully mixed evenly, and granulated according to the drum granulation method to obtain granules. The outer layer of the granules is coated with a sustained-release agent and dried to obtain the product.

Example 3

A potassium polyphosphate slow-release fertilizer for corn, comprising the following raw materials in parts by weight:

65 parts of urea; 50 parts of potassium polyphosphate; 15 parts of diammonium hydrogen phosphate; 0.8 parts of magnesium sulfate; 0.6 parts of calcium nitrate; 2.0 parts of trace elements; 10 parts of bone meal; 10 parts of humic acid; 6 parts; 15 parts of sustained-release agent; said trace elements and weight ratio are Fe:Mn:Zn:Cu:B:Mo=3:2:3:2:2:0.8.

Above-mentioned potassium polyphosphate corn slow-release fertilizer, the preparation method of described potassium polyphosphate comprises the following steps:

① Put yellow phosphorus in a combustion furnace and burn it at 700°C to get P ₂ O ₅ gas;

②Use a fan to pump the P ₂ O ₅ gas into the polymerization tower, continuously pour water to dissolve the P ₂ O ₅ gas into the water, until the weight concentration of P ₂ O ₅ in the solution reaches 87%, and obtain a solution;

3. in the solution that obtains, according to hydrogen sulfide gas: solution is 1:2000 weight ratio that hydrogen sulfide gas is passed into solution, and reaction generates arsenic sulfide solid, filters, and the arsenic content in detection solution drops to below 1PPM, and the content of heavy metal The content drops below 30 PPM to obtain polyphosphoric acid;

④ Slowly add the obtained polyphosphoric acid into the potassium hydroxide solution with a mass fraction of 80%, strictly control the reaction temperature at 45°C, stir while adding, react for 120 minutes, and detect K ₂ O and P in the product ₂ O ₅ weight percent content, the content of K ₂ O in the product is 33%, the content of P ₂ O ₅ is 10%, the reaction is completed, and potassium polyphosphate is prepared.

The preparation method of the slow-release agent is as follows: according to the weight ratio of polyvinyl alcohol: β-cyclodextrin: water is 3:5:85, first dissolve polyvinyl alcohol into hot water at 75°C, and stir for 4 minutes , and then add β-cyclodextrin, stir to dissolve, and mix evenly to prepare a sustained-release preparation.

The production method of described potassium polyphosphate corn slow release fertilizer is:

(1) Add magnesium sulfate, calcium nitrate and trace elements to potassium polyphosphate according to parts by weight, mix and stir for 20 minutes to obtain mixture A;

(2) Mix bone meal, decomposed cow dung, humic acid and deervine to obtain mixture B, then fully mix mixture A and mixture B, and finally add urea and diammonium hydrogen phosphate and mix evenly to obtain mixture C;

(3) The mixture C is pulverized by an automatic feeding system, fully mixed evenly, and granulated according to the drum granulation method to obtain granules. The outer layer of the granules is coated with a sustained-release agent and dried to obtain the product.

apply effects

For further illustrating the advantages of the potassium polyphosphate corn slow-release fertilizer that the present invention produces, the contriver adopts the potassium polyphosphate corn slow-release fertilizer that produces to carry out repeated tests in some large cornfields in Guangxi, wherein, The test situation in Binyang County, Nanning City, Guangxi is as follows:

1. The tested corn variety: Guidan 589.

2. Test settings:

Three treatments were set up in the experiment, and each treatment was repeated three times, arranged in random blocks, and the area of each treatment plot was 100m ² ; the experiment settings were as follows:

Treatment 1: When corn is planted, the potassium polyphosphate corn slow-release fertilizer prepared by the present invention is used as a base fertilizer at an application rate of 30kg/mu, and the urea with a N content of 46% is applied at a rate of 12kg/mu when the corn enters a large growth period. 1. Topdressing corn with calcium superphosphate containing P ₂ O ₅ 16% at an application rate of 4kg/mu;

Treatment 2: When corn is planted, the potassium polyphosphate corn slow-release fertilizer prepared by the present invention is used as a base fertilizer according to the application amount of 30kg/mu, and is applied once to people when the corn enters a large growth period, and no topdressing is applied;

Treatment 3: When corn is planted, use conventional corn fertilizer - use 15-15-15 compound fertilizer at an application rate of 30kg/mu as base fertilizer, and apply urea with a N content of 46% at a rate of 12kg/mu when the corn enters the large growth period 1. Topdressing corn with calcium superphosphate containing P ₂ O ₅ 16% at an application rate of 4kg/mu;

Planting and topdressing were carried out at the same time in the experiment, and other corn field management measures were the same.

4. Test results:

The effects of three groups of different treatments on corn grain quality and corn yield are shown in Table 1 below:

As can be seen from the above table 1, compared with the treatment 3 that does not use the potassium polyphosphate corn slow-release fertilizer of the present invention, the yield of corn and the yield of corn in the treatment 1 and treatment 2 of the potassium polyphosphate corn slow-release fertilizer of the present invention are applied. The contents of aspects such as bulk density, crude protein, crude fat, crude starch and lysine have all been improved, illustrate that using the potassium polyphosphate corn slow-release fertilizer of the present invention can greatly improve the quality and output of corn, and for all applied Treatment 1 and treatment 2 of the potassium polyphosphate corn slow-release fertilizer of the present invention, treatment 1 also carried out topdressing to corn in the later stage, and treatment 2 did not carry out topdressing, it can be seen through comparison that the two have little difference in terms of yield and quality, Illustrate that potassium polyphosphate corn slow-release fertilizer of the present invention has better slow-release effect, even do not apply urea etc. to carry out topdressing during the corn growth period, there is also certain fertilizer in the corn field to provide nutrients for the growth of corn, and then illustrates The slow-release potassium polyphosphate fertilizer for corn produced by the invention has good and long-lasting fertilizer effects. And after applying the potassium polyphosphate corn slow-release fertilizer of the present invention, the corn plants grow tall and strong, with less damage by diseases and insect pests, and the corn grains obtained by planting are plump.

Claims (4)

1. a kind of potassium polyphosphate corn slow-release fertilizer, it is characterised in that include the raw material of following parts by weight：

55-65 parts of urea；Potassium polyphosphate:45-50 parts；10-15 parts of diammonium hydrogen phosphate；0.5-0.8 parts of magnesium sulfate；Calcium nitrate 0.4-0.6 parts；It is micro- 1.5-2.0 parts；8-10 parts of bone meal；5-10 parts of humic acid；10-15 parts of decomposed cow dung；Trifoliate jewelvine 4-6 Part；10-15 parts of sustained release agent；

The production method of described potassium polyphosphate corn slow-release fertilizer is：

（1）Magnesium sulfate, calcium nitrate and trace element are added in potassium polyphosphate according to parts by weight and mix 15-20 Minute obtains mixture A；

（2）Bone meal, decomposed cow dung, humic acid and trifoliate jewelvine are mixed, mixture B is obtained, then by mixture A and mixture B is sufficiently mixed, and is eventually adding urea and diammonium hydrogen phosphate is well mixed, obtain mixture C；

（3）Mixture C is crushed through gravity system, fully blending is uniform, granulated by drum granulating method, and particle is made, Particle outer layer is wrapped and sustained release agent, is dried, is obtained product.

2. potassium polyphosphate corn slow-release fertilizer according to claim 1, it is characterised in that the system of described potassium polyphosphate Preparation Method comprises the following steps：

1. yellow phosphorus is placed in combustion furnace in being burnt at 500~700 DEG C, obtains P₂O₅Gas；

2. with blower fan by P₂O₅Gas is extracted into polymerization tower, and continuous water drenching makes P₂O₅Gas is molten into water, the P into solution₂O₅ Weight concentration reach 72~87%, obtain solution；

3. in obtained solution, according to hydrogen sulfide gas:Solution is 1:1000~2000 part by weight is by hydrogen sulfide gas It is passed through in solution, reaction generation arsenones solid, filtering, the arsenic content in detection solution drops to below 1PPM, heavy metal contains Amount drops to 30 below PPM, obtains polyphosphoric acids；

4. obtained polyphosphoric acids is slowly dropped in the potassium hydroxide solution that mass fraction is more than 65%, strict control is anti- The temperature answered is stirred when being added dropwise, reacted 120~180 minutes between 15~45 DEG C, K in detection product₂O and P₂O₅Weight Percentage composition, treats K in product₂O content is 33%, P₂O₅Content is 10%, and reaction terminates, and potassium polyphosphate is made.

3. potassium polyphosphate corn slow-release fertilizer according to claim 1, it is characterised in that described trace element and weight Than for Fe:Mn:Zn:Cu:B:Mo=3:2:3:2:2:0.8.

4. potassium polyphosphate corn slow-release fertilizer according to claim 1, it is characterised in that the preparation side of described sustained release agent Method is：According to polyvinyl alcohol:Beta-schardinger dextrin:Water is 2-3:4-5:75-85 part by weight, is first dissolved into 65- by polyvinyl alcohol In 75 DEG C of hot water, stir 4-5 minutes, then add beta-schardinger dextrin stirring and dissolving, be well mixed, sustained release agent is made.