Summer peanut controlled-release fertilizer as well as preparation method and application thereof

Abstract

The invention discloses a summer peanut controlled-release fertilizer as well as a preparation method and application thereof, and belongs to the technical field of peanut controlled-release functional fertilizers. The special controlled-release fertilizer for summer peanuts adopts a unique four-layer core-shell structure and is prepared from the following raw materials: 19 parts of urea, 7 parts of humic acid, 21 parts of monoammonium phosphate, 2 parts of boric acid, 2 parts of ammonium molybdate, 16 parts of potassium sulfate, 4 parts of bentonite, 8 parts of calcium peroxide, 6 parts of calcium magnesium phosphate fertilizer and 15 parts of sulfur. The special controlled-release coated fertilizer for summer peanuts disclosed by the invention realizes segmented controlled release, oxygenation and rooting, balanced fertilization, soil fertilization and complete degradation, and has relatively high economic value, social value and ecological value.

Description

Technical Field

[0001] The invention relates to the technical field of peanut controlled-release functional fertilizer, and in particular to a summer peanut controlled-release fertilizer and a preparation method and application thereof. Background Art

[0002] Summer peanuts are a general term for peanuts interplanted on wheat ridges and summer direct seeding (direct sowing after crops are harvested). Summer peanuts are mainly distributed in the Huanghuaihai River Basin and the middle and lower reaches of the Yangtze River. Summer peanuts have a short growing period, and are often planted after the previous crop is harvested. Therefore, land preparation is not strict, and problems such as soil compaction are prominent. Summer peanuts grow quickly, and the growth rates of plant height, leaf area, and flower volume are significantly faster than spring peanuts. Vegetative growth and reproductive growth coexist for a long time, and problems such as vigorous growth and repeated cropping all lead to reduced production. At the same time, summer peanuts are prone to rain and heat at the same time, which can easily cause peanuts to be in a flooded environment, causing waterlogging, leading to root necrosis, reduced production, disease and rot. The patent "CN110447493B A method for increasing peanut yield and a peanut planting method using the method" proposes to use a three-step comprehensive fertilization method of "basal fertilizer-needling topdressing-pod spraying fertilizer" to promote the maximum utilization of fertilizers. However, this method requires the application of different fertilizers at different stages of peanut sowing, peanut needle-setting period and peanut pod-setting period, and needs to be supplemented every 10 to 15 days. This method significantly increases the workload. Therefore, the development of new fertilizers that meet the fertilizer requirements of summer peanuts, balance soil nutrients and waterlogging adversity caused by special phenological environments is urgently needed to be launched. Summary of the invention

[0003] In view of the above-mentioned prior art, the purpose of the present invention is to provide a summer peanut controlled-release fertilizer and a preparation method and application thereof.

[0004] At present, there are many summer peanut fertilizers on the market, but their efficacy is limited and cannot meet the summer peanuts' requirements for soil improvement and comprehensive nutrient absorption. The peak period of summer peanut nutrient demand is during the flowering and needle-setting period, and problems such as nutrient deficiency and premature aging are prone to occur during the full fruit period, so segmented controlled release is more in line with crop needs. At the same time, the soil in summer peanut planting plots is compacted and prone to rain and waterlogging disasters, causing peanut roots to rot and lack of oxygen, affecting nutrient absorption efficiency, and urgently needing to release oxygen fertilizers. For peanuts, the demand for calcium is higher than that for phosphorus, ranking third. Peanuts are prone to root rot, fruit rot, and shriveled seeds. Therefore, the research and development of summer peanut special fertilizers should be combined with segmented controlled release, oxygenation and rooting, balanced fertilization, and soil fertilization.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect of the present invention, a controlled-release fertilizer for summer peanuts is provided, the controlled-release fertilizer for summer peanuts is composed of a 4-layer core-shell structure, which includes, from outside to inside: an outer coating, an outer core fertilizer, an inner coating and an inner core fertilizer;

[0007] The outer core fertilizer has the same composition as the inner core fertilizer, and includes the following raw materials by mass: 19 parts of urea, 7 parts of humic acid, 21 parts of monoammonium phosphate, 2 parts of boric acid, 2 parts of ammonium molybdate, 16 parts of potassium sulfate, and 4 parts of bentonite;

[0008] The outer coating comprises the following raw materials by weight: 8 parts of calcium peroxide and 6 parts of calcium magnesium phosphate;

[0009] The inner coating comprises the following raw materials by mass: 15 parts of sulfur.

[0010] Furthermore, the mass ratio of the outer core fertilizer to the inner core fertilizer is (0.2-5):1.

[0011] Furthermore, the controlled release period of the outer coating is 60 days to 80 days.

[0012] In some embodiments, the total nutrient release period is 100-140 days, and the controlled release period of the inner coating is 40-60 days.

[0013] The second aspect of the present invention provides a method for preparing the controlled-release fertilizer for summer peanuts, comprising the following steps:

[0014] (1) Mixing: Mixing raw materials as core fertilizers for 1-5 hours to obtain a mixed raw material;

[0015] (2) Granulation: Take 1 / 3 of the mass of the mixed raw materials for granulation;

[0016] (3) Drying: Dry the raw materials after granulation at a temperature of 200-300° C. for 2-10 hours;

[0017] (4) Coating: taking the dried raw materials and sulfur, and evenly coating the sulfur on the surface of the fertilizer particles to obtain sulfur-coated fertilizer;

[0018] (5) Secondary granulation: adding the sulfur-coated fertilizer to the remaining 2 / 3 of the mixed raw material in step (1) for secondary granulation;

[0019] (6) Drying: Drying the secondary granulated raw material at a temperature of 50-200° C. for a drying time of 2-10 hours to obtain a secondary granulated fertilizer;

[0020] (7) Secondary coating: Calcium peroxide and calcium magnesium phosphate fertilizer are used to form a coating solution and sprayed on the surface of the secondary granulated fertilizer;

[0021] (8) Drying: Drying the raw material treated in step (7) at a temperature of 50-200° C. for a drying time of 2-10 hours to obtain a controlled-release fertilizer for summer peanuts.

[0022] The third aspect of the present invention provides the use of the special controlled-release fertilizer for summer peanuts in promoting the growth and increasing the yield of peanuts.

[0023] Furthermore, the growth-promoting and yield-increasing method comprises:

[0024] (1) Nutrients are released in stages, and fertilizer is supplied in time during the critical fertilizer-required period, so that the plants bloom and set pods at the same time, the pods set are high, the fruit-filling rate is high, and the yield and quality are increased;

[0025] (2) Reduce the incidence of fruit rot;

[0026] (3) Regulate soil bulk density, increase the proportion of water-stable aggregates in the soil, improve soil porosity and water and fertilizer retention capacity, and improve soil fertility;

[0027] (4) Slow and long-term release of oxygen. When summer peanuts are affected by the rainy and flooded environment in summer, it can improve root respiration, promote root growth, and reduce the damage caused by flooding and anaerobic root retting;

[0028] (5) The coating material is degradable and will not remain for a long time, thus reducing environmental pollution and not affecting the growth and development of the root system.

[0029] Beneficial effects of the present invention:

[0030] The present invention adjusts the traditional single-layer film process to a double-layer film process. The fertilizer is accurately proportioned according to the nutritional needs of the crops, and can supply the crops with multiple nutrients required by the crops in a relatively balanced and long-term manner, thereby improving the fertilization effect.

[0031] In terms of precise proportions: balance the macro, medium, trace and organic matter in the soil; calcium supplementation can prevent the growth of peanuts from being short and the fruit from being deformed; boron supplementation can promote flowering and fertilization, increase the fruit filling rate and yield; molybdenum supplementation can promote root growth, improve nitrogen fixation and protein synthesis. Appropriate supplementation of these elements can significantly improve the quality and yield of peanuts.

[0032] In terms of membrane material selection: calcium peroxide is used as the membrane material to provide a stable supply of oxygen, eliminate the problem of hypoxia caused by compaction and flooding, promote root respiration and growth, improve nutrient absorption and utilization efficiency, promote growth and development, and reduce disease and decay rates. Reduce soil bulk density, increase porosity, improve water and fertilizer retention and air permeability, increase the content of soil available nutrients, increase soil microbial activity, and improve soil fertility.

[0033] In terms of segmented controlled release: during the flowering and needle-setting period, and the pod-setting and fruit-full period, nutrients are released in stages, and fertilizer supply is timely and sufficient, which promotes root growth, photosynthesis and dry matter accumulation, thereby increasing production and improving quality.

[0034] In terms of environmental protection: the coating material of the present invention is degradable, which reduces environmental pollution. The material can be decomposed in the natural environment without long-term residue, thus preventing soil pollution and promoting sustainable agricultural development. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the four-layer core-shell structure of a controlled-release fertilizer specifically for summer peanuts.

[0036] Figure 2 This is a graph showing the total nutrient release / demand pattern of summer peanuts and different fertilizers.

[0037] Figure 3 This is a graph showing oxygen release from different fertilizers. DETAILED DESCRIPTION

[0038] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0039] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

[0040] Summer peanuts absorb less nitrogen, phosphorus, and potassium from seedling to flowering, accounting for 1%, 5%, and 5% of the total absorption, respectively. As the peanuts grow and develop, the absorption gradually increases, and in the pod expansion period, the absorption of nitrogen, phosphorus, and potassium increases sharply, with nitrogen accounting for 40% of the total, phosphorus accounting for 32%, and potassium accounting for 37%. As the peanuts gradually mature, from expansion to maturity, the absorption of nitrogen, phosphorus, and potassium reaches a peak, accounting for 42% of the total absorption of nitrogen, 47% of phosphorus, and 38% of potassium. In terms of nutrient absorption, the nutrients absorbed in the seedling stage are less, and the nutrient absorption rises sharply after flowering, and it is close to the maximum value when the pod expansion stops.

[0041] The necessity of using controlled-release fertilizer for summer peanuts is mainly reflected in the following aspects: controlled-release fertilizer can effectively control the release of nutrients to meet the needs of peanuts at different growth stages; promote the growth of peanut plants in the middle and late stages, increase the leaf area index and photosynthetic rate; significantly increase the number of fruits per plant and the number of full fruits, and ultimately increase the yield. In addition, controlled-release fertilizer also has the advantages of reducing nutrient loss and improving fertilizer utilization, and is one of the important measures to achieve high yield and high efficiency of summer peanuts.

[0042] In the current summer peanut fertilization process, the nutrients of ordinary fertilizers are released too quickly in the early stage, resulting in slender main stems of seedlings, lodging in the later stage, and aggravating the occurrence of diseases. The flowering needle period of summer peanuts is mostly in the rainy season. Continuous rainfall causes the nutrients of ordinary fertilizers to leach quickly, and peanuts have no nutrient supply in the later stage, resulting in fertilizer deficiency and shriveled pods. Compared with spring peanuts, summer peanuts have tight rotation time, poor land preparation quality, and serious soil compaction problems. Fertilizers are mostly applied to the 0-10cm soil layer. Therefore, affected by factors such as light, the fertilizer utilization rate is low. At present, farmers use more chlorine-based fertilizers to reduce investment, but peanuts have a high demand for sulfur. The continuous use of chlorine-based fertilizers has led to soil sulfur deficiency. Peanuts show yellowing leaves and reduced photosynthesis efficiency of leaves. Plant growth will be significantly inhibited, showing short plants, small leaves, and easy petiole breakage. In severe cases, it may even lead to plant death.

[0043] In addition, the simultaneous occurrence of rain and heat in summer can easily lead to flooding and hypoxia in peanut roots, which seriously affects the growth and development of peanuts during key periods such as flowering and needle formation. The adverse summer environment also makes the damage of repeated cropping such as nutrient deficiency, disease and rot more prominent.

[0044] Therefore, we proposed a controlled-release fertilizer specifically for summer peanuts based on the current fertilizer requirements of summer peanuts.

[0045] Urea, the role and function of urea fertilizer are mainly reflected in providing nitrogen elements needed by plants, promoting plant root development, regulating plant growth balance and synergistic effects with other nutrients. Reasonable use of urea fertilizer can increase crop yields, improve quality and promote sustainable agricultural development. Urea is small-particle urea with a particle size of 2mm and a nitrogen content of 46%.

[0046] Humic acid, a humic acid fertilizer made by combining it with elements such as nitrogen, phosphorus, and potassium (for example, humic acid can be made into ammonium humate fertilizer by neutralizing humic acid with ammonia), has the functions of increasing fertilizer efficiency, improving soil, stimulating crop growth, and improving the quality of agricultural products.

[0047] Monoammonium phosphate can promote photosynthesis, protein synthesis and growth.

[0048] Potassium sulfate, potassium sulfate fertilizer can slowly dissolve in the soil. Its chemical composition can improve the soil and make it more fertile, thus providing a good environment for crops. Potassium sulfate fertilizer contains elements such as potassium, zinc, and boron, which can supplement soil nutrients and then provide for plant growth. After applying potassium sulfate fertilizer, crops will grow more vigorously and have stronger fruit-bearing ability.

[0049] Boric acid can promote flowering and pollination of peanuts and increase the fruit setting rate.

[0050] Ammonium molybdate can enhance nitrogen fixation by rhizobia and promote the absorption of nitrogen, phosphorus, potassium and other elements by peanuts.

[0051] Bentonite can improve physical properties, increase the particle size and looseness of fertilizers, prevent fertilizers from agglomerating, and facilitate transportation, storage, and use. At the same time, it can improve stability, fix nitrogen, potassium, and organic matter, reduce fertilizer losses in the soil, and improve fertilizer stability in the soil.

[0052] Calcium peroxide. Using calcium peroxide as a coating material is an innovative fertilizer preparation technology. Calcium peroxide coated fertilizer can continuously provide oxygen to plants in the soil, help improve the soil environment, and promote the growth and development of plant roots. Calcium hydroxide (Ca(OH)2) produced by the decomposition of calcium peroxide is alkaline and can neutralize the acidity of the soil and adjust the pH value of the soil. This is an important advantage for peanuts in acidic sandy soils. The calcium ions (Ca 2+ ) can combine with the colloids in the soil to form a stable soil structure. This helps to enhance the water retention and air permeability of the soil, providing a better growth environment for plants.

[0053] Calcium magnesium phosphate fertilizer uses calcium magnesium phosphate as a coating material and wraps it on the surface of quick-acting fertilizer. It can control the release rate of nutrients, improve fertilizer utilization, and reduce nutrient loss. It is suitable for long-term fertilization and specific crops, and has the advantages of good environmental protection effect and low price.

[0054] Sulfur. The use of sulfur to make sulfur-coated controlled-release fertilizers can achieve continuous and stable nutrient release, slow down the nutrient release rate, and enable nutrients to be continuously and stably supplied to crops to meet the long-term nutritional needs of crops. Since the nutrient release rate of sulfur-coated fertilizers is slowed down, the loss and volatilization of nutrients are reduced, thereby improving the utilization rate of fertilizers. Compared with traditional fertilizers, sulfur-coated fertilizers can significantly increase the yield and quality of crops. During the production process, sulfur-coated fertilizers will not pollute the soil and groundwater. At the same time, due to the slow release of nutrients, the number and amount of fertilization are reduced, the cost of agricultural production is reduced, and the efficiency of agricultural production is improved.

[0055] The experimental materials used in the examples of the present invention but not specifically described are all conventional experimental materials in the art and can be purchased through commercial channels.

[0056] Example 1: Preparation of controlled-release fertilizer for summer peanuts

[0057] The controlled-release fertilizer for summer peanuts is calculated by mass and includes the following raw materials: 19 parts of urea, 7 parts of humic acid, 21 parts of monoammonium phosphate, 2 parts of boric acid, 2 parts of ammonium molybdate, 16 parts of potassium sulfate, 4 parts of bentonite, and the coating layer materials: 15 parts of sulfur, 8 parts of calcium peroxide, and 6 parts of calcium magnesium phosphate.

[0058] The above raw materials are used to prepare a controlled-release fertilizer specifically for summer peanuts, and the specific steps are as follows:

[0059] (1) Mixing: Urea, humic acid, monoammonium phosphate, boric acid, ammonium molybdate and potassium sulfate are placed in a mixer according to a certain proportion and mixed. Bentonite is added during the mixing process to achieve compounding. The mixing time is 2 hours to obtain a mixed raw material.

[0060] (2) Granulation: Place 1 / 3 of the mass of the mixed raw materials into a granulator for granulation.

[0061] (3) Drying: The granulated raw materials were placed in a dryer for drying at a temperature of 260° C. for 5 hours.

[0062] (4) Coating: The dried raw materials are placed in a coating machine and heated to a certain temperature. The sulfur is heated until it is melted and added to the coating machine so that the sulfur is evenly coated on the surface of the fertilizer particles to obtain sulfur-coated fertilizer.

[0063] (5) Secondary granulation: Add the sulfur-coated fertilizer to the remaining 2 / 3 of the mixed raw materials in step (1), and place the mixture in a granulator for secondary granulation.

[0064] (6) Drying: The secondary granulated raw material was placed in a dryer for drying at a temperature of 90° C. for 5 hours to obtain a secondary granulated fertilizer.

[0065] (7) Secondary coating: After the calcium peroxide and calcium magnesium phosphate fertilizer are crushed, a certain amount of water is added and stirred to form a suspended coating liquid. The coating liquid is evenly sprayed on the surface of the secondary granulated fertilizer through a spray device.

[0066] (8) Drying: The raw material treated in step (7) is placed in a dryer for drying at a temperature of 100° C. for a drying time of 5 hours; water is evaporated by heating, and a film of calcium peroxide and calcium magnesium phosphate is formed on the surface of the fertilizer, thereby obtaining a controlled-release fertilizer for summer peanuts.

[0067] Comparative Example 1: Preparation of single-layer coated fertilizer

[0068] The difference between the single-layer coated fertilizer and the controlled-release fertilizer for summer peanuts in Example 1 is that the single-layer coating is performed using the coating layer material according to the proportion in Example 1.

[0069] The raw materials in Example 1 were prepared according to the following steps:

[0070] (1) Mixing: placing urea, humic acid, monoammonium phosphate, boric acid, ammonium molybdate and potassium sulfate in a mixer according to a certain proportion and mixing them. During the mixing process, bentonite is added to achieve compounding. The mixing time is 2 hours to obtain a mixed raw material.

[0071] (2) Granulation: placing the mixed raw materials into a granulator for granulation;

[0072] (3) Drying: The granulated raw materials are placed in a dryer for drying at a temperature of 260° C. for 5 hours;

[0073] (4) Coating: The dried raw materials are placed in a coating machine and heated to a certain temperature. The coating materials calcium peroxide, calcium magnesium phosphate and sulfur are crushed, heated until the sulfur melts, and added to the coating machine. The coating materials are evenly coated on the surface of the fertilizer particles to produce a single-layer coated fertilizer.

[0074] Comparative Example 2: Preparation of uncoated fertilizer

[0075] The difference between the uncoated fertilizer and the controlled-release fertilizer for summer peanuts in Example 1 is that the uncoated fertilizer is prepared by a direct mixing method according to the proportions in Example 1 and does not contain a coating layer material.

[0076] Example 2: Determination of slow-release effect of fertilizer

[0077] The total nutrient content of fertilizer is one of the important indicators to measure the efficiency of fertilizer. According to "GB 18382-2021 Fertilizer Labeling Content and Requirements", the total nutrient refers to the sum of the three main nutrients of nitrogen (N), phosphorus (P2O5), and potassium (K2O), and does not include other elements or compounds.

[0078] Take the controlled-release fertilizer for summer peanuts prepared in Example 1 ( Figure 2 The single-layer coated fertilizer prepared in Comparative Example 1 ( Figure 2 The uncoated fertilizer prepared in Comparative Example 2 ( Figure 2 10g of each of the following (represented as uncoated) were added to 200g of dry sand, and 100ml of water was added every 3 days. The fertilizer release rate (%) was measured on fixed days to verify the slow-release effect of the fertilizer. Three parallels were set up and a plot was made against the fertilizer requirements of peanuts. The test results are shown in Figure 2 shown.

[0079] Results Figure 2 , comparing the changes in the total nutrient demand of summer peanuts at different stages, the summer peanut-specific controlled-release fertilizer prepared in Example 1 is closer to the summer peanut fertilizer requirement. The peak fertilizer requirements of summer peanuts are 65 days and 105 days, respectively, and the peak fertilizer requirements of special fertilizers are 60 days and 102 days, respectively. Therefore, the fertilizer utilization rate is higher, and fertilizer saving and efficiency improvement are achieved. The peak period of total nutrient release of uncoated fertilizers is 28 days, and the release amount is 20.2%, while the demand for summer peanuts at this time is only 5.8%, resulting in a low fertilizer utilization rate. The peak period of total nutrient release of single-layer film fertilizers is 63 days, and the release amount is 16.2%. Although this is close to the peak period of peanut fertilizer demand, the total nutrient supply is insufficient in the later peanut fruit-filling period, which easily causes the peanut pods to shrivel and seriously reduce production.

[0080] Figure 2 It shows that the initial nutrient release of the uncoated fertilizer is getting faster and faster, and the nutrient release is basically completed in 90 days. Although the single-layer film provides nutrient supply in time during the peanut needle-setting period, the nutrient supply is insufficient during the full fruit period, causing the grains to shrivel. The controlled-release coating specially used for summer peanuts of the present invention shows a double peak release rate performance at 60 days and 102 days during the entire nutrient release detection period. The nutrient release law is consistent with the law of double peaks of nutrient demand during the flowering needle-setting period and the full fruit period of peanuts. During the two key fertilizer-requiring periods of peanuts, the controlled-release coated fertilizer specially used for summer peanuts of the present invention is more in line with the fertilizer demand law of peanuts, provides sufficient nutrients, has a longer nutrient supply time, and has higher nutrient utilization efficiency, which can meet the production goals of peanut fertilizer saving, increased yield and increased efficiency.

[0081] Example 3: Determination of oxygen release

[0082] Oxygen release is mainly due to the action of the outer membrane. The oxygen release of controlled-release fertilizer and calcium peroxide for summer peanuts was measured. The measurement method was based on the method of "Experimental Study on the Application of Calcium Peroxide in Direct Seeding of Rice (2002(04):360-362)".

[0083] The results are as follows Figure 3 As shown, by recording the oxygen release of the device for 68 days, it can be found that compared with the use of calcium peroxide alone, the controlled-release fertilizer for summer peanuts can release oxygen slowly and evenly to ensure the growth and development of the root system of peanuts in the seedling stage. The oxygen supply advantage of the controlled-release fertilizer for summer peanuts designed by this patent is mainly reflected in the performance in the mid-term (rainy season). The growth period of summer peanuts is 100-120 days. The rainy season in the main production area of ​​Huanghuaihai is generally from July to August. Summer peanuts are sown in mid-June. Although calcium peroxide is used alone to release oxygen to alleviate the problems of root rot and aggravation of diseases caused by hypoxia, the oxygen release is too fast and only lasts for more than 40 days. It cannot solve the problem of obstructed root respiration when the rainy season comes. Although calcium peroxide is also selected as the coating material of the controlled-release fertilizer for summer peanuts of the present invention, the supply time is extended, and it can be released continuously for about 70 days, ensuring the healthy growth of summer peanuts in the high temperature and high humidity environment of the rainy season from July to August, achieving the effects of anti-lodging, anti-disease, and anti-root rot, which is more in line with the growth needs of peanuts and achieves sufficient nutrient supply.

[0084] Test Example 1: Experiment to verify the effect of controlled-release fertilizer

[0085] 1.1 Basic situation of trial implementation

[0086] Test location: Demonstration base in Xianggou Town, Zhucheng City, Weifang City

[0087] The basic soil nutrients are: 66.75g / kg alkaline nitrogen, 13.29mg / kg available phosphorus, 105.21mg / kg available potassium, 13.31g / kg organic matter, and pH 6.1.

[0088] Test crop: Huayu 917.

[0089] Experimental period: June to October.

[0090] 1.2 Experimental design

[0091] The experiment was designed with three treatment groups: group T1, which was applied with the controlled-release fertilizer specially prepared in Example 1 for summer peanuts at a dosage of 50 kg / mu; group T2, which was applied with the single-layer coated fertilizer prepared in Comparative Example 1 at a dosage of 50 kg / mu; group CK, which was applied with the uncoated fertilizer prepared in Comparative Example 2 at a dosage of 50 kg / mu; and multiple indicators were tested during the harvest period.

[0092] 1.3 Results Analysis

[0093] 1.3.1 Effects of different fertilizers on the incidence of peanut fruit rot

[0094] Table 1 Effect of different treatments on the incidence of peanut fruit rot

[0095]

[0096] As shown in Table 2, the T1 group can significantly reduce the incidence of fruit rot compared with the CK and T2 groups, with the incidence rate reduced by 43.7% and 37.1%. There was no significant difference in the incidence of peanut fruit rot between the T2 group and the CK group. The application of summer peanut fertilizer can significantly reduce the incidence of peanut fruit rot by releasing oxygen, promoting root growth, and improving stress resistance.

[0097] 1.3.2 Effects of different fertilizers on soil water-stable aggregates during peanut harvest

[0098] Table 3 Particle size distribution of soil water-stable aggregates at different peanut harvesting stages (%)

[0099]

[0100] As shown in Table 2, compared with T2 and CK groups, the proportion of soil water-stable aggregates with a particle size of >0.25 mm in T1 group increased significantly by 8.91% and 11.61%. Compared with CK, the proportion of soil water-stable aggregates in the particle size ranges of 2-3 mm, 1-2 mm, 0.5-1 mm, and 0.25-0.5 mm in T1 increased significantly. Compared with CK, only the proportion of soil water-stable aggregates in the particle size ranges of 0.5-1 mm and 0.25-0.5 mm increased significantly in T2, and there was no difference in the proportion of soil water-stable aggregates in other particle size ranges.

[0101] 1.3.3 Effects of different fertilizers on soil chemical properties during peanut harvest

[0102] Table 4 Soil chemical properties of peanuts at harvest time under different treatments

[0103]

[0104]

[0105] As shown in Table 3, compared with the CK group, the T1 group significantly increased soil pH, alkaline nitrogen, available phosphorus, available potassium and organic matter content by 0.11 units, 14.99%, 5.41%, 5.53% and 4.03%, respectively. Compared with the T2 group, the T1 group significantly increased soil pH and organic matter content by 0.08 units and 2.20%, respectively. Compared with the CK group, the soil pH and organic matter content did not change significantly, and the soil alkaline nitrogen, available phosphorus and available potassium increased significantly by 11.21%, 3.19 and 4.06%, respectively.

[0106] 1.3.4 Soil physical and chemical properties experiment

[0107] Table 4 Performance of soil physical and chemical properties using special fertilizers

[0108]

[0109] Table 4 shows that compared with the T2 group and the CK group, the soil bulk density of the T1 group was significantly reduced, the porosity was significantly increased, the maximum field water holding capacity of the soil was significantly increased, and the looseness of the soil physical structure was increased; the utilization rate of soil nitrogen, phosphorus and potassium was improved, and the utilization efficiency of nitrogen, phosphorus and potassium nutrients in fertilizers was significantly improved; the carbon and nitrogen contents in rhizosphere soil microorganisms were significantly increased, and the activity of soil microorganisms increased significantly.

[0110] 1.3.5 Yield Experiment

[0111] Test method:

[0112] The grouping setting is the same as the experimental design of Example 1.2, with a planting area of ​​667m 2 , sown after wheat harvest on June 7 and harvested on October 1. The experimental peanut variety was Huayu 917, with a planting density of 8333 holes per mu, two peanuts per hole.

[0113] The following data need to be determined:

[0114] (1) Survey on the growth and development of peanuts. The survey records the dates of sowing, germination, and harvest. During the harvest period, a sampling survey of plants is conducted. In each plot, a sampling point with consistent growth is selected. Ten consecutive plants are selected and the main stem height, side branch length, number of green leaves on the main stem, number of full fruits, number of empty fruits, number of rotten fruits, number of young fruits, etc. are recorded for each plant.

[0115] (2) Yield measurement: measure the yield of all crops collected in the plot. Collect and dry crops in each plot individually.

[0116] (3) Yield calculation and seed testing: After the pods are fully dried, remove impurities, young fruits, rotten fruits, etc., and weigh them according to the plots to calculate yield. Randomly sample 500 grams of the dried pods for testing.

[0117] Result analysis:

[0118] Table 5 Plant characteristics of different treatments

[0119]

[0120] Table 6 Yield and yield components of different treatments

[0121]

[0122] As shown in Tables 5 and 6, the application of summer peanut special controlled-release fertilizer has a certain effect on the productivity of individual plants compared with ordinary fertilizers. Among them, T1 has the highest productivity of 30.17g per plant. From the yield results, T2 produces 276.81kg of pods per mu, an increase of 7.97% over the control, CK, and T1 produces 278.89kg of pods per mu, an increase of 8.78% over the control. This experiment shows that the application of summer peanut special controlled-release fertilizer can effectively increase the yield of peanut pods, and the yield increase is greater when 40kg per mu is applied.

[0123] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A controlled-release fertilizer for summer peanuts, characterized in that: The controlled-release fertilizer for summer peanuts is composed of a 4-layer core-shell structure, which includes, from the outside to the inside: an outer coating, an outer core fertilizer, an inner coating and an inner core fertilizer; The outer core fertilizer has the same composition as the inner core fertilizer, and includes the following raw materials by mass: 19 parts of urea, 7 parts of humic acid, 21 parts of monoammonium phosphate, 2 parts of boric acid, 2 parts of ammonium molybdate, 16 parts of potassium sulfate, and 4 parts of bentonite; The outer coating comprises the following raw materials by weight: 8 parts of calcium peroxide and 6 parts of calcium magnesium phosphate; The inner coating comprises the following raw materials by mass: 15 parts of sulfur.

2. The controlled-release fertilizer for summer peanuts according to claim 1, characterized in that: The mass ratio of the outer core fertilizer to the inner core fertilizer is (0.2-5):

1.

3. The controlled-release fertilizer for summer peanuts according to claim 1, characterized in that: The controlled release period of the outer coating is 60 to 80 days.

4. The method for preparing the controlled-release fertilizer for summer peanuts according to any one of claims 1 to 3, characterized in that: The steps include: (1) Mixing: Mixing raw materials as core fertilizers for 1-5 hours to obtain a mixed raw material; (2) Granulation: Take 1 / 3 of the mass of the mixed raw materials for granulation; (3) Drying: Dry the raw materials after granulation at a temperature of 200-300° C. for 2-10 hours; (4) Coating: taking the dried raw materials and sulfur, and evenly coating the sulfur on the surface of the fertilizer particles to obtain sulfur-coated fertilizer; (5) Secondary granulation: adding the sulfur-coated fertilizer to the remaining 2 / 3 of the mixed raw material in step (1) for secondary granulation; (6) Drying: Drying the secondary granulated raw material at a temperature of 50-200° C. for a drying time of 2-10 hours to obtain a secondary granulated fertilizer; (7) Secondary coating: Calcium peroxide and calcium magnesium phosphate fertilizer are used to form a coating solution and sprayed on the surface of the secondary granulated fertilizer; (8) Drying: Drying the raw material treated in step (7) at a temperature of 50-200° C. for a drying time of 2-10 hours to obtain a controlled-release fertilizer for summer peanuts.

5. Use of the controlled-release fertilizer for summer peanuts according to any one of claims 1 to 3 in promoting growth and increasing yield of peanuts.

6. The use according to claim 5, characterized in that: The growth-promoting and yield-increasing methods include: (1) Nutrients are released in stages, and fertilizer is supplied in time during the critical fertilizer-required period, so that the plants bloom and set pods at the same time, the pods set are high, the fruit-filling rate is high, and the yield and quality are increased; (2) Reduce the incidence of fruit rot; (3) Regulate soil bulk density, increase the proportion of water-stable aggregates in the soil, improve soil porosity and water and fertilizer retention capacity, and improve soil fertility; (4) Slow and long-term release of oxygen. When summer peanuts are affected by the rainy and flooded environment in summer, it can improve root respiration, promote root growth, and reduce the damage caused by flooding and anaerobic root retting; (5) The coating material is degradable and will not remain for a long time, thus reducing environmental pollution and not affecting the growth and development of the root system.

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