Biogas slurry-based watermelon package fertilizer capable of increasing sugar and yield and application of biogas slurry-based watermelon package fertilizer

Abstract

The invention discloses a sugar-increasing and yield-increasing biogas slurry-based watermelon package fertilizer and application thereof, and belongs to the technical field of watermelon fertilizers. According to the biogas slurry-based watermelon package fertilizer provided by the invention, the comprehensive efficiency of the fertilizer is remarkably improved, the nutritional requirements of watermelons in the whole growth period are met, the photosynthetic efficiency can be optimized, the plant root system and vegetative growth are effectively promoted, the nutrient utilization rate is improved, and the watermelon yield and the watermelon farmer income are further remarkably increased; the flavor and the nutritional value of the fruits are greatly improved; the moisture content and porosity of applied soil are remarkably improved, so that the soil structure is effectively improved, and the water retention and air permeability of the soil are improved; rich agricultural waste biogas slurry in northwest regions is used as a raw material, so that the production cost is greatly reduced, and meanwhile, the waste treatment pressure is reduced; the chemical fertilizer application amount is reduced, environmental pollution is reduced, the soil microbial community structure is improved, and continuous cropping obstacles are relieved; the method is a green fertilization scheme with high yield, high quality and sustainable development, and has extremely high popularization value and application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of watermelon fertilizers, in particular to a biogas slurry-based watermelon fertilizer package capable of increasing sugar and yield and application thereof. Background Art

[0002] Integrated water-fertilizer technology has become widespread in watermelon cultivation, especially in greenhouse watermelon cultivation. However, the problem persists: average fertilizer application rates far exceed national recommended standards, while nutrient utilization rates are very low. Studies have shown that the average fertilizer application rates for greenhouse watermelon cultivation include 1.9 times, 3.6 times, and 2.3 times the recommended N, P2O5, and K2O, respectively, while nutrient utilization rates are as low as 8%-29%. Excessive fertilization not only hinders improvements in watermelon yield, quality, and economic benefits, but also exacerbates soil salinization and even causes a series of environmental problems, including groundwater contamination. Furthermore, unbalanced organic and inorganic nutrient ratios, unscientific fertilizer-to-topdressing ratios, and a mismatch between nutrient element ratios and watermelon growth requirements further hinder the high-quality development of the greenhouse watermelon industry.

[0003] Package fertilizers refer to a series of fertilizer combinations that can meet the nutritional needs of crops at different growth stages and in different aspects. The core of the package fertilizer is to scientifically combine and precisely formulate several fertilizers according to the nutrient needs of different crops at different times, ultimately achieving comprehensive nutrition and efficient fertilization. Currently, most of the fertilizers available on the market for drip irrigation of watermelons are general-purpose products, which have the following main problems:

[0004] (1) Insufficient precision in the division of growth periods: The existing standards for dividing the growth periods of watermelons are relatively rough, making it difficult to accurately match the dynamic nutrient requirements of the plants at different stages. Especially during the critical period from fruit setting to fruit expansion, there is a deviation between nutrient supply and growth rhythm, which affects the yield and quality of watermelons.

[0005] (2) The contradiction between the performance and cost of liquid fertilizer: Some liquid fertilizer packages rely on chemical synthetic raw materials, with high production costs and energy consumption. In addition, the nutrient release pattern is different from the watermelon growth cycle, making it difficult to achieve precise fertilizer supply.

[0006] (3) The rhythm of fertilizer release does not match: Traditional solid package fertilizers dissolve slowly, resulting in insufficient fertilizer supply in the seedling stage and excess nutrients in the later stage; the nutrient release rhythm of existing liquid fertilizers also fails to fully match the growth needs of watermelons, affecting fertilizer utilization.

[0007] (4) Nutrient synergy and imbalance: The proportion of chemical fertilizers in the fertilization plan is too high, the ratio of organic and inorganic nutrients is not coordinated, and the supplementation of trace elements lacks systematicity; the degree of integration of liquid fertilizers with solid fertilizers and organic raw materials is low, and the synergistic effect of nutrients cannot be fully exerted.

[0008] (5) Lack of precise adaptability: Most of the fertilizers used for drip irrigation of greenhouse watermelons on the market are general formulas. There is a lack of customized products for different growth stages and planting environments. It is difficult to meet the precise matching of plant needs and environmental characteristics, which limits the increase in greenhouse watermelon production. Summary of the Invention

[0009] The purpose of the present invention is to provide a biogas slurry-based watermelon package fertilizer for increasing sugar and yield and its application. In order to solve the problems in the prior art, a liquid package fertilizer for watermelon is provided, which has a balanced organic-inorganic ratio, zero solids, dynamically regulated nutrient release, and deep fusion and synergistic efficiency. It can significantly improve the comprehensive efficiency of the fertilizer, meet the nutritional needs of watermelon throughout its entire growth period, and is suitable for watermelon.

[0010] To achieve the above-mentioned objectives, the present invention provides a biogas slurry-based watermelon fertilizer package for increasing sugar and yield, comprising rooting water, fertilizer for vine-forming period, fertilizer for fruit-setting period and fertilizer for fruit-swelling period; the rooting water is an aqueous solution of Bacillus subtilis; the fertilizer for vine-forming period is a mixture of treated biogas slurry, potassium sulfate and urea; the fertilizer for fruit-setting period is a mixture of treated biogas slurry, potassium sulfate, urea, Paenibacillus polymyxa, medium and trace element fertilizer and trehalose; and the fertilizer for fruit-swelling period is a mixture of treated biogas slurry, potassium sulfate and urea.

[0011] Preferably, the fertilizer used during the vine-pulling period also includes Bacillus subtilis, mineral-derived potassium humate and trehalose.

[0012] Preferably, the final concentration of Bacillus subtilis in the fertilizer used during the vine-growing period is 5-10 kg / 667 m 2 The final concentration of urea is 1-10kg / 667m 2 The final concentration of potassium sulfate is 1-5kg / 667m 2 The final concentration of mineral potassium fulvic acid is 1-2kg / 667m 2 , the final concentration of trehalose is 1-10%.

[0013] Preferably, the final concentration of Bacillus subtilis in the rooting water is 11kg / 667m 2 .

[0014] Preferably, the final concentration of potassium sulfate in the fertilizer used during the fruit setting period is 1-5 kg / 667 m 2 The final concentration of urea is 1-5kg / 667m 2 The final concentration of trace element fertilizer is 5-20kg / 667m 2 .

[0015] Preferably, the final concentration of potassium sulfate in the fertilizer used during the fruit expansion period is 20-50kg / 667m 2 The final concentration of urea is 30-50kg / 667m 2 .

[0016] Preferably, the treated biogas slurry refers to the fermented biogas slurry being initially filtered through a filter with a pore size of ≤1mm to remove large particles of impurities, secondarily filtered through a filter with a pore size of ≤0.1mm to remove suspended matter, and microfiltered through a filter with a pore size of ≤0.1mm, and a three-stage purification process to ensure that the impurity and pollutant content of the biogas slurry meets the standards.

[0017] Preferably, the rooting water is applied once a week after the watermelon seedlings are planted, and the application rate is 67456L / 667m 2 During the vine-pulling period, fertilizer should be applied once after the watermelon seedlings have grown 4-5 true leaves and the vines begin to stretch. Before the buds appear, the watermelon seedlings should be flushed with water at a rate of 67456L / 667m 2 During the fruit setting period, fertilizer should be applied to the watermelon seedlings from flowering and pollination to the fruit setting period. Fertilizer should be applied once with water. The application rate is 67456L / 667m 2 During the fruit expansion period, fertilizer should be applied from the beginning when the young fruit is firmly planted to the time when the fruit stops increasing in size. Fertilize the watermelon seedlings three times with water, and the amount of each application is 67456L / 667m 2 , each time with an interval of 1 week.

[0018] Preferably, the rooting water, the fertilizer for the fruit setting period and the fertilizer for the fruit swelling period are all left to stand at room temperature before being applied.

[0019] The biogas slurry-based watermelon fertilizer package for increasing sugar content and yield as described above is used in watermelon planting.

[0020] This invention leverages the richness of biogas slurry in humic acid, amino acids, and various trace elements. By selecting suitable fertilizer types and employing gradient mixing and high-speed homogenization, the fertilizer and biogas slurry are fully integrated to create a zero-solids liquid fertilizer. By precisely controlling the ratio of organic and inorganic nutrients, this fertilizer not only provides a comprehensive and balanced supply of macronutrients and trace elements for watermelon growth, but also significantly improves the fertilizer's overall effectiveness through the synergistic effect of organic and inorganic nutrients, meeting the nutritional needs of watermelons throughout their entire growth period.

[0021] Therefore, the biogas slurry-based watermelon package fertilizer for increasing sugar and yield and its application provided by the present invention have the following specific technical effects:

[0022] (1) The biogas slurry-based watermelon fertilizer package provided by the invention not only provides a comprehensive and balanced supply of macroelements and microelements for watermelon growth by precisely controlling the ratio of organic and inorganic nutrients, but also significantly improves the comprehensive efficiency of the fertilizer through the synergistic effect of organic and inorganic nutrients, meets the nutritional needs of watermelon throughout its growth period, optimizes photosynthetic efficiency, effectively promotes plant root system and nutritional growth, improves nutrient utilization, and thus significantly increases watermelon yield and farmers' income;

[0023] (2) Compared with watermelons treated with chemical fertilizers, watermelon treated with the biogas slurry-based watermelon fertilizer provided by the present invention showed a maximum increase of 59.38% in watermelon red pigment and 54.91% in soluble sugar. Furthermore, the content of vitamin C, soluble protein, and reducing sugar was also increased, thereby significantly improving the flavor and nutritional value of the fruit.

[0024] (3) The biogas slurry-based watermelon fertilizer package provided can significantly increase the moisture content and porosity of the applied soil, up to 41.40% and 28.15% respectively compared with the soil applied with chemical fertilizers; and significantly reduce the bulk density, up to 46.80% compared with the soil applied with chemical fertilizers, thereby effectively improving the soil structure, increasing soil water retention and air permeability;

[0025] (4) The provided biogas slurry-based watermelon fertilizer package utilizes the abundant agricultural waste biogas in the northwest region as raw material, which greatly reduces production costs and reduces the pressure of waste disposal. At the ecological level, it reduces the amount of chemical fertilizers used, reduces environmental pollution, improves the structure of soil microbial communities, and alleviates the problem of continuous cropping. It is a green fertilization program that takes into account high yield, high quality, and sustainable development, and has extremely high promotion value and application prospects.

[0026] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0028] Figure 1 The following are field photos of plants at different stages in the effect test examples of the present invention; A is a photo after planting; B is a photo during the vine-sprouting stage; C is a photo during the fruit-setting stage; and D is a photo during the fruit-swelling stage.

[0029] Figure 2 These are some on-site photos of the planting and harvesting in the effect test example of the present invention; A is a photo of the melon when it was growing in the greenhouse; B is a photo of the melon when it was harvested;

[0030] Figure 3 The statistical results of single fruit weight and per mu yield of watermelons with different treatments in the effect test example of the present invention are shown in FIG. 1 , wherein (a) is the statistical result of single fruit weight; (b) is the statistical result of per mu yield;

[0031] Figure 4The following are photos of watermelons taken in various embodiments when examining the nutritional quality in the effect test examples of the present invention; A is Example 1; B is Example 2; C is Example 3; D is Example 4; and E is Example 5.

[0032] Figure 5 The statistical results of the nutritional quality of watermelons with different treatments in the effect test example of the present invention are shown in FIG. 1 , wherein A is the soluble sugar content; B is the reducing sugar content; C is the VC content; D is the lycopene content; E is the soluble protein content; and F is the titratable acid content. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0034] In order to make the purpose, technical solutions and advantages of the present application clearer, more thorough and more complete, the technical solutions of the present invention are clearly and completely described below through the accompanying drawings and Examples. The following detailed description is an explanation of the embodiments and is intended to provide further details of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the application belongs.

[0035] The instruments, equipment, and reagents used in the examples were all obtained through commercial channels; the methods and steps not described in detail in the examples are conventional technical means in the field; mineral fulvic acid was purchased from Shanghai Hulian Biopharmaceutical (Xiayi) Co., Ltd.; the biogas slurry was provided by Lanzhou Xinrong Company, which was obtained from the fermentation of waste vegetables and municipal wastewater, and the biogas slurry used was collected and set aside.

[0036] The urea fertilizer, potassium sulfate fertilizer, and trace element fertilizers used in the examples are all commercial fertilizers, with N content of 46% or higher in the urea fertilizer; K2O content of 52% or higher in the potassium sulfate fertilizer; and CaO content of 30%, SiO2 content of 20%, MgO content of 10%, and chelated zinc content of 0.1% or higher in the trace element fertilizer.

[0037] Example 1

[0038] A biogas slurry-based watermelon fertilizer package for increasing sugar and yield is prepared as follows:

[0039] (1) The biogas slurry collected from the fermentation of waste vegetables and municipal wastewater is treated by a three-stage purification process: first, a filter with a pore size of ≤1mm is used for preliminary filtration to remove large particles of impurities, and then the biogas slurry obtained from the preliminary filtration is subjected to a filter with a pore size of ≤0.1mm for secondary filtration to remove suspended matter, and the biogas slurry obtained from the secondary filtration is subjected to microfiltration using a filter with a pore size of ≤0.1mm to ensure that the impurity and pollutant content of the biogas slurry meets the standards of "Biogas Fertilizer" (NY2596-2022).

[0040] (2) Preparation of fertilizers for different growth stages:

[0041] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0042] Fertilizer application during vine growth period: 360kg / 667m 2 (1) Partially treated biogas slurry, 8.3kg / 667m 2 Bacillus subtilis, 5% trehalose, 1.8kg / 667m 2 Weigh each component of the mineral source potassium fulvic acid.

[0043] Fertilizer during fruit setting period: 47.5kg / 667m 2 Weigh (1) part of the treated biogas slurry, 10kg / 667m 2 Weigh each component of the medium and trace element fertilizer.

[0044] Fertilizer application during fruit expansion period: 1278kg / 667m 2 Weigh the treated biogas slurry from part (1).

[0045] (3) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2 After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch, and before the buds appear, the watermelon seedlings should be fertilized with water once during the vine growth period. The amount of fertilizer applied is 67456L / 667m 2 During the period from flowering and pollination to fruit set (fruits grow to the size of an egg and no longer fall off), water the watermelon seedlings with fertilizer for fruit set once, with a flushing rate of 67456L / 667m 2 From the time when the young fruit begins to set firmly until the fruit stops growing in size, apply fertilizer for the fruit expansion period three times with water, and the amount of each application is 67456L / 667m 2 , each time with an interval of 1 week.

[0046] Example 2

[0047] The biogas slurry treated in part (1) of Example 1 was used to prepare a biogas slurry-based watermelon fertilizer package for increasing sugar and yield, as follows:

[0048] (1) Preparation of fertilizers for different growth stages:

[0049] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0050] Fertilizer application during vine growth period: 360kg / 667m2 Example 1 (1) Partially treated biogas slurry, 2.7kg / 667m 2 Potassium sulfate fertilizer, 9.2kg / 667m 2 Urea fertilizer, 8.3kg / 667m 2 Bacillus subtilis, 5% trehalose, 1.8kg / 667m 2 Weigh each component of the mineral source potassium fulvic acid.

[0051] Fertilizer during fruit setting period: 47.5kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 4.1kg / 667m 2 Potassium sulfate fertilizer, 1.37kg / 667m 2 Urea fertilizer, 10kg / 667m 2 Weigh each component of the medium and trace element fertilizer and mix them evenly.

[0052] Fertilizer application during fruit expansion period: 1278kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 30kg / 667m 2 Potassium sulfate fertilizer, 40kg / 667m 2 Weigh each component of the urea fertilizer and mix them evenly.

[0053] (2) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2 After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch. For the watermelon seedlings before budding, use gradient mixing and high-speed homogenization to fully blend the fertilizer and biogas slurry. Then, apply fertilizer once with water for the vine extension period. The application rate is 67456L / 667m 2 During the period from flowering and pollination to fruit set (when the fruit grows to the size of an egg and no longer falls off), the fertilizer and biogas slurry are fully blended by gradient mixing and high-speed homogenization. The fertilizer for fruit set is applied once with water, with an application rate of 67456L / 667m 2 From the time when the young fruit begins to settle to the time when the fruit stops growing, the fertilizer and biogas slurry are fully blended by gradient mixing and high-speed homogenization. The fertilizer for the fruit expansion period is applied three times with water, and the amount of each application is 67456L / 667m 2 , each time with an interval of 1 week.

[0054] Example 3

[0055] The biogas slurry treated in part (1) of Example 1 was used to prepare a biogas slurry-based watermelon fertilizer package for increasing sugar and yield, as follows:

[0056] (1) Preparation of fertilizers for different growth stages:

[0057] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0058] Fertilizer application during vine growth period: 360kg / 667m 2 Example 1 (1) Partially treated biogas slurry, 2.7kg / 667m 2 Potassium sulfate fertilizer, 9.2kg / 667m 2 Urea fertilizer, 8.3kg / 667m 2 Bacillus subtilis, 5% trehalose, 1.8kg / 667m 2 Weigh each component of the mineral source potassium fulvic acid.

[0059] Fertilizer during fruit setting period: 47.5kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 4.1kg / 667m 2 Potassium sulfate fertilizer, 1.37kg / 667m 2 Urea fertilizer, 1.7kg / 667m 2 of Paenibacillus polymyxa, 5% trehalose, 10kg / 667m 2 Weigh each component of the medium and trace element fertilizer and mix them evenly.

[0060] Fertilizer application during fruit expansion period: 1278kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 30kg / 667m 2 Potassium sulfate fertilizer, 40kg / 667m 2 Weigh each component of the urea fertilizer and mix them evenly.

[0061] (2) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2 After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch. For the watermelon seedlings before budding, use gradient mixing and high-speed homogenization to fully blend the fertilizer and biogas slurry. Then, apply fertilizer once with water for the vine extension period. The application rate is 67456L / 667m 2 For watermelon seedlings from flowering and pollination to fruit set (fruits grow to the size of an egg and no longer fall off), use gradient mixing and high-speed homogenization to fully blend chemical fertilizers with biogas slurry, and apply fertilizer for fruit set once with water. The application rate is 67456L / 667m 2From the time when the young fruit is firmly planted to the time when the fruit stops growing, use gradient mixing and high-speed homogenization to fully blend the fertilizer with the biogas slurry, and apply the fertilizer for the fruit expansion period three times with water, with each application amount of 67456L / 667m 2 , each time with an interval of 1 week.

[0062] Example 4

[0063] The biogas slurry treated in part (1) of Example 1 was used to prepare a biogas slurry-based watermelon fertilizer package for increasing sugar and yield, as follows:

[0064] (1) Preparation of fertilizers for different growth stages:

[0065] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0066] Fertilizer application during vine growth period: 360kg / 667m 2 Weigh the biogas slurry after the treatment of part (1) of Example 1, 2.7kg / 667m 2 Potassium sulfate fertilizer, 9.2kg / 667m 2 Urea fertilizer, 8.3kg / 667m 2 Bacillus subtilis, 5% trehalose, 1.8kg / 667m 2 Mineral source of potassium fulvic acid.

[0067] Fertilizer during fruit setting period: 47.5kg / 667m 2 Weigh the biogas slurry after the treatment of part (1) of Example 1, 4.1kg / 667m 2 Potassium sulfate fertilizer, 1.37kg / 667m 2 Urea fertilizer, 10kg / 667m 2 To prepare the medium and trace element fertilizer, just mix the ingredients evenly.

[0068] Fertilizer application during fruit expansion period: 1920kg / 667m 2 Weigh the biogas slurry after the treatment of part (1) of Example 1, 43kg / 667m 2 Potassium sulfate fertilizer, 46.5kg / 667m 2 Urea fertilizer, just mix the ingredients evenly.

[0069] (2) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch. For the watermelon seedlings before budding, use gradient mixing and high-speed homogenization to fully blend the fertilizer and biogas slurry. Then, apply fertilizer once with water for the vine extension period. The application rate is 67456L / 667m 2 For watermelon seedlings from flowering and pollination to fruit set (fruits grow to the size of an egg and no longer fall off), use gradient mixing and high-speed homogenization to fully blend chemical fertilizers with biogas slurry, and apply fertilizer for fruit set once with water. The application rate is 67456L / 667m 2 From the time when the young fruit is firmly planted to the time when the fruit stops growing, use gradient mixing and high-speed homogenization to fully blend the fertilizer with the biogas slurry, and apply the fertilizer for the fruit expansion period three times with water, with each application amount of 67456L / 667m 2 , each time with an interval of 1 week.

[0070] Example 5

[0071] The biogas slurry treated in part (1) of Example 1 was used to prepare a biogas slurry-based watermelon fertilizer package for increasing sugar and yield, as follows:

[0072] (1) Preparation of fertilizers for different growth stages:

[0073] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0074] Fertilizer application during vine growth period: 360kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 2.7kg / 667m 2 Potassium sulfate fertilizer, 9.2kg / 667m 2 Urea fertilizer, 8.3kg / 667m 2 Bacillus subtilis, 5% trehalose, 1.8kg / 667m 2 Weigh each component of the mineral source potassium fulvic acid.

[0075] Fertilizer during fruit setting period: 47.5kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 4.1kg / 667m 2 Potassium sulfate fertilizer, 1.37kg / 667m 2 Urea fertilizer, 1.7kg / 667m 2 of Paenibacillus polymyxa, 5% trehalose, 10kg / 667m 2 Weigh each component of the medium and trace element fertilizer and mix them evenly.

[0076] Fertilizer application during fruit expansion period: 1920kg / 667m 2 The biogas slurry after partial treatment of (1) in Example 1, 43kg / 667m 2 Potassium sulfate fertilizer, 46.5kg / 667m 2 Weigh each component of the urea fertilizer and mix them evenly.

[0077] (2) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2 After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch. For the watermelon seedlings before budding, use gradient mixing and high-speed homogenization to fully blend the fertilizer and biogas slurry. Then, apply fertilizer once with water for the vine extension period. The application rate is 67456L / 667m 2 For watermelon seedlings from flowering and pollination to fruit set (fruits grow to the size of an egg and no longer fall off), use gradient mixing and high-speed homogenization to fully blend chemical fertilizers with biogas slurry, and apply fertilizer for fruit set once with water. The application rate is 67456L / 667m 2 From the time when the young fruit is firmly planted to the time when the fruit stops growing, use gradient mixing and high-speed homogenization to fully blend the fertilizer with the biogas slurry, and apply the fertilizer for the fruit expansion period three times with water, with each application amount of 67456L / 667m 2 , 3 times with 1 week interval.

[0078] Control Example

[0079] (1) Preparation of fertilizers for different growth stages:

[0080] Rooting water: 11kg / 667m 2 Weigh Bacillus subtilis (viable count ≥ 10 11 CFU / g) was mixed with water and then applied.

[0081] Fertilizer during the vine-growing period: 2kg / 667m 2 Diammonium phosphate, 3kg / 667m 2 Potassium sulfate fertilizer, 10kg / 667m 2 Urea fertilizer is weighed and mixed with water before application.

[0082] Fertilizer during fruit setting period: 3kg / 667m 2 Diammonium phosphate, 4.1kg / 667m 2 Potassium sulfate fertilizer, 1.43kg / 667m 2 Weigh each component of urea fertilizer, mix with water and then apply.

[0083] Fertilizer for fruit expansion period: 7kg / 667m 2Diammonium phosphate, 30kg / 667m 2 Potassium sulfate fertilizer, 33kg / 667m 2 Weigh each component of urea fertilizer, mix with water and then apply.

[0084] (2) Application method: After the prepared rooting water is left at room temperature for 1 hour, it is applied once a week after the watermelon seedlings are planted, with an application rate of 67456L / 667m 2 After the watermelon seedlings have grown 4-5 true leaves, the vines begin to stretch, and before the buds appear, the watermelon seedlings should be fertilized with water once during the vine growth period. The amount of fertilizer applied is 67456L / 667m 2 From the time of watermelon flowering and pollination to the time of fruit set (when the fruit grows to the size of an egg and no longer falls off), apply fertilizer for the fruit set period once with water, with an application rate of 67456L / 667m 2 From the time when the young fruit is firmly planted to the time when the fruit stops growing, apply fertilizer for the fruit expansion period three times with water, and the amount of each application is 67456L / 667m 2 , each time with an interval of 1 week.

[0085] Effect test example

[0086] 1. Test location: greenhouse in Dalui Town, Liangzhou District, Wuwei City, Gansu Province.

[0087] 2. Test conditions:

[0088] Wuwei City is located in Gansu Province, at the eastern end of the Hexi Corridor and the northern foot of the Qilian Mountains. It has a temperate continental arid climate, characterized by drought and little rainfall, abundant sunshine, and large temperature differences between day and night. It is an ideal production area for high-quality watermelons in China.

[0089] 3. Test materials:

[0090] These are "Jingmei 2K" watermelon seedlings with two leaves and one heart, purchased from a seedling base.

[0091] 4. Experimental design

[0092] The experimental area is approximately 0.7 mu, and the plot area is 37.08m 2 , no base fertilizer was applied, and each plot was planted with "Jingmei 2K" watermelon seedlings purchased from the seedling base. The watermelon seedlings were seedlings with a matrix, with a planting row spacing of 80 cm and a plant spacing of 40 cm. 40 watermelon plants were planted in each plot. Fertilization was performed using the fertilizers, application methods, and application rates in Examples 1 to 5 and the control example, respectively. Each seedling only retained one main branch and one melon, without side branches and flowers. Field photos of plants at different stages are shown in the figure below. Figure 1 shown.

[0093] 5. Experimental results and analysis.

[0094] (1) Impact on leaf growth.

[0095] Leaves are not only the "energy factory" for watermelon growth, but also the core node for nutrient and water regulation. Their health directly determines the degree of realization of yield potential and fruit quality. The maximum leaf area, chlorophyll content of functional leaves, and leaf nitrogen content of functional leaves were measured at the flowering and fruiting period, fruit swelling period, and maturity period. The chlorophyll content of functional leaves (SPAD) and leaf nitrogen content were measured using a portable handheld chlorophyll meter. Leaf area = longest leaf (cm) * widest leaf (cm) * 0.65, and the position is always the 5th to 7th true leaf from the root. The growth of watermelon leaves under different treatments is shown in Table 1. The results show that the fertilizers of Example 3 and Example 2 performed best, with the maximum leaf area being 444.28±16.87cm 2 and 437.67±41.34cm 2 , significantly higher than the control example. The chlorophyll content (SPAD) is the highest in Example 3 and Example 2, which are 45.02±3.72 and 44.94±2.09 respectively, which are significantly better than the control example, indicating that the biogas slurry-based watermelon package fertilizer in Example 3 is more conducive to chlorophyll accumulation. In terms of leaf nitrogen content, Example 3 is significantly higher than the control group, indicating that it has a strong ability to promote nitrogen absorption. In summary, although the biogas slurry-based watermelon package fertilizer in Example 3 inhibits leaf area growth, it significantly improves chlorophyll and nitrogen content.

[0096] Table 1 Leaf growth statistics

[0097]

[0098] (2) Impact on single fruit weight and per mu yield.

[0099] Only one melon was left on each plant, and side branches, other flowers, and melons were removed promptly. After the fruits matured, 5 watermelons were selected from each plot and pollinated on the same day. Representative watermelons were harvested 45 days after pollination. Single fruit weight and per-acre yield were measured. Some on-site photos of planting and harvesting are shown below. Figure 2 The statistical results of single fruit weight and per mu yield of watermelon under different treatments are shown in Figure 3 The results show that the single fruit weight and per mu yield of the biogas slurry-based watermelon package fertilizers of Examples 1 to 5 are significantly higher than those of the control example. Compared with the control example, the single fruit weight of Examples 1 to 5 increases by 19.24%-24.29%, among which the single fruit weight of Example 3 is 2.25 kg, which is significantly higher than the control example, an increase of 24.29%; the per mu yield of Examples 1 to 5 increases by 19.23%-24.28% compared with the control example, among which the per mu yield of Example 3 is 4846.00 kg·667 m -2 , significantly higher than the control, an increase of 24.28%.

[0100] (3) Impact on nutritional quality.

[0101] Three representative watermelons were selected from each plot and pollinated on the same day, 45 days after pollination, for sampling. The pictures of the watermelons taken in each embodiment are as follows: Figure 4 As shown. Coomassie brilliant blue G-250 staining, spectrophotometry, 3,5-dinitrosalicylic acid method, NaOH titration, molybdenum blue colorimetry, 3,5-dinitrosalicylic acid colorimetry were used to investigate the soluble protein content, watermelon red pigment content, reducing sugar content, titratable acid content, VC content and soluble sugar content of watermelon. The nutritional quality of watermelon under different treatments is shown as follows. Figure 5 As shown, the results show that compared with the control example, the soluble protein content of Examples 1 to 5 was increased by 28.68%-67.12%, among which Example 3 increased by 67.12%; the lycopene content of Examples 1 to 5 was increased by 6.37%-79.73%, among which Example 3 increased by 79.73%; the reducing sugar content of Examples 1 to 5 was increased by 0.64%-43.20%; the titratable acid content of Examples 1 to 5 was reduced by 32.49%-64.93%, among which Example 3 reduced by 64.93%; the soluble sugar content of Examples 1 to 5 was increased by 5.12%-44.75%, among which Example 3 increased by 44.75%.

[0102] (4) Impact on soil physical properties.

[0103] The physical properties of watermelon soil under different treatments are shown in Table 2. The results show that when the soil after harvest is compared with the soil before fertilization, the soil moisture content increased by 17.50%-50.98%, of which Examples 3 and 4 significantly increased by 48.13% and 50.98% respectively. The soil bulk density was significantly reduced in each example, decreasing by 23.81%-31.97% compared to before fertilization. The soil porosity increased by 29.02%-39.17%, of which Example 3 had a porosity of 62.21%, a significant increase of 39.17% compared to before planting. These changes all indicate that the biogas slurry-based watermelon meal prepared in Examples 1 to 5 can significantly improve the soil environment and increase the soil moisture content and porosity.

[0104] Table 2 Statistics of soil physical and chemical properties

[0105]

[0106]

[0107] Different letters after the values ​​indicate significant differences (P<0.05)

[0108] (5) Impact on economic benefits.

[0109] The economic benefits of watermelon under different treatments are shown in Table 4. The results show that due to the large fluctuations in market prices, the average price of 2.5 yuan kg -1 Calculate the output value. The biogas slurry-based watermelon meal packages of Examples 1 to 5 increased the income by 14.55%-18.67% compared with the control example. The per mu yield of Examples 2 and 3 increased by 22.30% and 24.28% respectively. Although the fertilizer cost increased, the income increased by 1669.44 yuan / 667m2 compared with chemical fertilizer. -2 and 1735.81 yuan·667m -2 .

[0110] Table 4 Economic Benefit Statistics

[0111]

[0112] Therefore, the biogas slurry-based watermelon package fertilizer provided by the present invention significantly improves the comprehensive efficiency of fertilizers, meets the nutritional needs of watermelons throughout the entire growth period, and can also optimize photosynthetic efficiency, effectively promote plant root system and nutritional growth, improve nutrient utilization rate, and thus significantly increase watermelon yield and watermelon farmers' income; greatly improve the flavor and nutritional value of the fruit; significantly increase the moisture content and porosity of the applied soil, and thus effectively improve the soil structure, and improve the soil water retention and air permeability; utilize the abundant agricultural waste biogas slurry in the northwest region as raw material, significantly reduce production costs, and at the same time reduce waste treatment pressure; reduce the amount of chemical fertilizer application, reduce environmental pollution, improve the soil microbial community structure, and alleviate continuous cropping obstacles; it is a green fertilization plan that takes into account high yield, high quality, and sustainable development, and has extremely high promotion value and application prospects.

[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A biogas slurry-based watermelon fertilizer package for increasing sugar and yield, characterized in that: It includes rooting water, fertilizer for vine-growing period, fertilizer for fruit setting period and fertilizer for fruit swelling period; the rooting water is an aqueous solution of Bacillus subtilis; the fertilizer for vine-growing period is a mixture of treated biogas slurry, potassium sulfate and urea; the fertilizer for fruit setting period is a mixture of treated biogas slurry, potassium sulfate, urea, Bacillus polymyxa, medium and trace element fertilizer and trehalose; the fertilizer for fruit swelling period is a mixture of treated biogas slurry, potassium sulfate and urea.

2. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: Fertilizers used during the vine-growing period also include Bacillus subtilis, mineral potassium humate and trehalose.

3. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 2, characterized in that: The final concentration of Bacillus subtilis in the fertilizer used during the vine-pulling period is 5-10kg / 667m 2 The final concentration of urea is 1-10kg / 667m 2 The final concentration of potassium sulfate is 1-5kg / 667m 2 The final concentration of mineral potassium fulvic acid is 1-2kg / 667m 2 , the final concentration of trehalose is 1-10%.

4. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: The final concentration of Bacillus subtilis in the rooting water was 11 kg / 667 m 2 .

5. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: The final concentration of potassium sulfate in the fertilizer used during the fruit setting period is 1-5kg / 667m 2 The final concentration of urea is 1-5kg / 667m 2 The final concentration of trace element fertilizer is 5-20kg / 667m 2 .

6. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: The final concentration of potassium sulfate in the fertilizer used during the fruit expansion period is 20-50kg / 667m 2 The final concentration of urea is 30-50kg / 667m 2 .

7. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: The treated biogas slurry refers to the fermented biogas slurry that is initially filtered through a filter with a pore size of ≤1mm to remove large particles of impurities, then filtered through a filter with a pore size of ≤0.1mm for secondary filtration to remove suspended matter, and then filtered through a filter with a pore size of ≤0.1mm for microfiltration. This three-stage purification process ensures that the impurity and pollutant content of the biogas slurry meets the standards.

8. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 1, characterized in that: Rooting water should be applied once a week after watermelon seedlings are planted, with a flushing volume of 67456L / 667m 2 During the vine-pulling period, fertilizer should be applied once after the watermelon seedlings have grown 4-5 true leaves and the vines begin to stretch. Before the buds appear, the watermelon seedlings should be flushed with water at a rate of 67456L / 667m 2 During the fruit setting period, fertilizer should be applied to the watermelon seedlings from flowering and pollination to the fruit setting period. Fertilizer should be applied once with water. The application rate is 67456L / 667m 2 During the fruit expansion period, fertilizer should be applied from the beginning when the young fruit is firmly planted to the time when the fruit stops increasing in size. Fertilize the watermelon seedlings three times with water, and the amount of each application is 67456L / 667m 2 , each time with an interval of 1 week.

9. The biogas slurry-based watermelon fertilizer package for increasing sugar and yield according to claim 8, characterized in that: Rooting water, fertilizer for fruit setting period and fertilizer for fruit swelling period should be left at room temperature before application.

10. Use of the biogas slurry-based watermelon fertilizer package for increasing sugar content and yield as claimed in any one of claims 1 to 9 in watermelon cultivation.

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