A fertilization method to improve the yield and quality of alfalfa in sandy soil

Abstract

This invention belongs to the field of plant cultivation technology, specifically relating to a fertilization method for improving the yield and quality of alfalfa in sandy soil. The fertilization method includes: applying base fertilizer to the soil before planting, applying seed fertilizer at the time of alfalfa sowing, and further includes the following steps: irrigating 4 to 5 times during each alfalfa growing season, including 2 times of integrated water and fertilizer irrigation; during integrated water and fertilizer irrigation, water is applied first, and then fertilizer is added to the water before continuing irrigation; the fertilizer consists of urea, monoammonium phosphate, potassium chloride, and zinc sulfate, and the mass ratio of urea, monoammonium phosphate, potassium chloride, and zinc sulfate is 1.875–4:2.875–5.6:0.875–2.4:0.2–0.36. This invention not only solves the problem of low yield and poor quality of alfalfa in sandy soil areas of Northwest China due to poor water and fertilizer retention capacity and severe water and fertilizer leakage, but also significantly reduces planting costs.

Description

Technical Field

[0001] This invention belongs to the field of plant cultivation technology, specifically relating to a fertilization method for improving the yield and quality of alfalfa in sandy soil. Background Technology

[0002] Alfalfa, a perennial high-quality legume forage, is known as the "King of Forages" due to its high yield, excellent quality, and strong adaptability. It plays an important role in adjusting my country's agricultural planting structure and supporting animal husbandry.

[0003] However, alfalfa, as a water-intensive plant, differs significantly from traditional annual crops such as cotton, wheat, and corn in its production methods, water-saving irrigation, and fertilization techniques. These crops have different characteristics in terms of growth cycle, water requirements, and nutrient absorption. Therefore, different planting and management strategies are needed. However, currently, farmers and herders often use wheat and corn planting methods when cultivating alfalfa, neglecting its special needs and restricting the improvement of its yield and quality. Especially in the sandy soil areas of Northwest China, due to the special geographical environment, soil barriers, limited water and heat resources, and terrain limitations, the water and fertilizer retention capacity of these lands is weak, directly affecting the growth environment of alfalfa and agricultural productivity. In addition, because sandy soil has poor water and fertilizer retention capacity, even if farmers and herders invest a lot of fertilizer, it cannot be guaranteed that alfalfa can fully absorb and utilize it, resulting in low fertilizer utilization rate and increased planting costs. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a fertilization method to improve the yield and quality of alfalfa in sandy soil. By rationally combining irrigation and fertilization, and limiting the number and time of irrigation, as well as the number, time and amount of fertilization, this method not only effectively solves the problems of low yield and poor quality of alfalfa in sandy pasture fields in Northwest China, which are caused by poor water and fertilizer retention capacity and serious water and fertilizer leakage, but also significantly reduces planting costs.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The purpose of this invention is to provide a fertilization method for improving the yield and quality of alfalfa in sandy soil, including applying base fertilizer to the soil before planting, applying seed fertilizer when sowing alfalfa, and further including the following steps:

[0007] Irrigation and fertilization are combined, with irrigation done 4 to 5 times during each alfalfa growing season, including 2 times of fertigation. The alfalfa can be harvested 4 times during its growing season, for a total of 8 topdressing irrigations.

[0008] When implementing integrated water and fertilizer irrigation, first irrigate with water, and then add fertilizer to the water to continue irrigation.

[0009] The fertilizer is composed of urea, monoammonium phosphate, potassium chloride and zinc sulfate, and the mass ratio of urea, monoammonium phosphate, potassium chloride and zinc sulfate is 1.875~4:2.875~5.6:0.875~2.4:0.2~0.36.

[0010] Preferably, the total amount of fertilizer used during the growth period of alfalfa is: 15 kg / mu to 20 kg / mu of urea, 23 kg / mu to 28 kg / mu of monoammonium phosphate, 7 kg / mu to 12 kg / mu of potassium chloride, and 2 kg / mu to 3 kg / mu of zinc sulfate.

[0011] Preferably, the two irrigations of integrated water and fertilizer are carried out during the first and third irrigations during the growth period of each crop of alfalfa. Alfalfa can only regenerate after the first irrigation following the harvest of each crop. At this time, the combination of irrigation and fertilization can significantly improve the regeneration rate of alfalfa and make an important contribution to the later yield.

[0012] Preferably, each irrigation lasts 4 to 5 hours per acre, and the flow rate for each irrigation is 8 m³. 3 / h~10m 3 / h.

[0013] Preferably, the operation of each fertigation irrigation is as follows: first irrigate with water for 2 hours / acre, then add fertilizer to the water and continue irrigating for 2 to 3 hours / acre, with a flow rate of 8 m³ / acre for each irrigation. 3 / h~10m 3 / h.

[0014] Preferably, during each fertigation irrigation, first irrigate with water for 2 hours per acre, then add fertilizer to the fertilizer container, stir thoroughly to dissolve evenly, and then inject it into the irrigation pipeline using fertigation equipment, such as a fertilizer pump, continuing irrigation for 2 to 3 hours per acre, with each irrigation flow rate being 8 m³ / acre. 3 / h~10m 3 / h.

[0015] Preferably, the irrigation is drip irrigation or sprinkler irrigation.

[0016] Preferably, the drip irrigation adopts shallow buried drip irrigation technology, with its branch pipes made of PE90 flexible hoses and the capillary tubes made of embedded drip irrigation tapes, and the branch pipes buried 8cm to 10cm below the ground surface.

[0017] Preferably, the sprinkler irrigation adopts semi-fixed sprinkler irrigation technology, the vertical pipe of the semi-fixed sprinkler irrigation adopts low elevation angle nozzles, and the branch pipes of the semi-fixed sprinkler irrigation are buried 15cm to 20cm below the ground surface.

[0018] Preferably, the sprinkler head is a plastic rocker arm type sprinkler head or an aluminum alloy sprinkler head.

[0019] Preferably, the base fertilizer is applied in conjunction with land preparation before planting alfalfa. The base fertilizer is organic fertilizer, selected from well-rotted farmyard manure, with an organic matter content ≥25%, nitrogen content ≥0.7%, phosphorus content ≥0.5%, and potassium content ≥0.4%. The application rate of the organic fertilizer is 5m³. 3 / mu~8m 3 / mu.

[0020] Preferably, the seed fertilizer is applied to the soil at a depth of 3cm to 5cm below the seed or 3cm to 5cm beside the seed using a seeder when sowing alfalfa.

[0021] Preferably, the fertilizer used is a compound fertilizer, which consists of urea, monoammonium phosphate and potassium chloride. The total amount of fertilizer used is: 3 kg / mu to 5 kg / mu of urea, 5 kg / mu to 7 kg / mu of monoammonium phosphate and 3 kg / mu to 5 kg / mu of potassium chloride.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. This invention provides a fertilization method to improve the yield and quality of alfalfa in sandy soil. By combining irrigation with fertilization and limiting the number of irrigations, time and amount of fertilizer used in the integrated water and fertilizer system, it not only effectively solves the problems of low yield and poor quality caused by poor water and fertilizer retention capacity and serious water and fertilizer leakage in alfalfa pasture fields in Northwest China, but also significantly reduces planting costs.

[0024] a. Determining the Number of Fertilizations: Alfalfa needs immediate irrigation after each harvest to regenerate. Therefore, combining irrigation and fertilization after the first harvest significantly improves the regeneration rate and makes a crucial contribution to later yield accumulation. However, excessive fertilization increases the production and management costs of alfalfa. Therefore, fertilization during the first and third irrigations after each harvest yields the most significant improvement in alfalfa production.

[0025] b. Determining the timing of fertilization: To improve water and fertilizer utilization efficiency, irrigation and fertilization should follow the principle of small, frequent applications. That is, each alfalfa growing season lasts 30-45 days, with 4-5 irrigations per crop, each lasting 4-5 hours per acre, and each irrigation flow rate being 8 m³ / acre. 3 / h~10m 3The irrigation rate is [amount] / h to ensure sufficient water supply for alfalfa during its growth. Two irrigations are fertigation (water and fertilizer integrated), namely the first and third irrigations. For each fertigation, first apply 2 hours / acre of sprinkler or drip irrigation water, then add the fertigation fertilizer to the fertilizer container, dissolve it evenly, and then inject it into the sprinkler or drip irrigation pipes using the fertigation equipment to continue irrigation. This ensures the fertilizer reaches the alfalfa root zone along with the sprinkler or drip irrigation water, maximizing its effectiveness.

[0026] c. Determining the amount of fertilizer: Throughout the entire growth period of alfalfa, the following fertilizers are required: 20-25 kg / mu of urea, 30-35 kg / mu of monoammonium phosphate, 10-15 kg / mu of potassium chloride, and 5 m³ of organic fertilizer. 3 / mu~8m 3 / mu, zinc sulfate 2kg / mu to 3kg / mu. According to the screening results, the application of base fertilizer when planting alfalfa in sandy soil has little impact on the yield and quality of alfalfa. Therefore, based on the characteristics of alfalfa seed germination, seedling growth and biomass accumulation, the total amount of fertilizer is allocated to each irrigation with integrated water and fertilizer.

[0027] 2. This invention provides a fertilization method to improve the yield and quality of alfalfa in sandy soil. Compared with the prior art, i.e., Comparative Example 1, under the same plot conditions, this invention can still increase the total annual output value of alfalfa hay while reducing the amount of fertilizer applied. Specifically, when the total amount of urea, monoammonium phosphate, and potassium chloride is reduced by 14%, the total annual yield of alfalfa still increases by 20.12%. Attached Figure Description

[0028] Figure 1 This is a comparison chart showing the yield of four harvests of alfalfa hay using the fertilization methods of Example 1 and Comparative Example 1 of the present invention.

[0029] Figure 2 This is a comparison chart showing the yield of fresh alfalfa harvested from four crops using the fertilization methods of Example 1 and Comparative Example 1 of the present invention.

[0030] Figure 3 This is a comparison chart showing the crude protein content of four harvests of alfalfa hay using the fertilization methods of Example 1 and Comparative Example 1 of the present invention.

[0031] Figure 4 This is a comparison chart showing the acid detergent fiber content of four harvests of alfalfa hay using the fertilization methods of Example 1 and Comparative Example 1 of the present invention.

[0032] Figure 5 This is a comparison chart showing the acid detergent fiber content of four harvests of alfalfa fresh grass harvested using the fertilization methods of Example 1 and Comparative Example 1 of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the data in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all fertilizers and equipment used in the following embodiments of this invention can be purchased from the market.

[0035] Currently, farmers and herders still use traditional planting methods for crops like wheat and corn when cultivating alfalfa, neglecting the specific needs of alfalfa as forage, which restricts the effective improvement of alfalfa yield and quality. Furthermore, the main problem facing alfalfa cultivation in the sandy soil regions of Northwest China is that the natural characteristics of sandy soil limit its water and fertilizer retention capacity, significantly weakening the effectiveness of irrigation and fertilization. Moreover, because water and nutrients are easily lost rapidly through the cracks in the sandy soil, they are difficult for alfalfa roots to effectively absorb and utilize. This rapid loss of water and fertilizer resources not only increases planting costs but also severely hinders the normal growth of alfalfa, resulting in low yields and difficulty in guaranteeing quality.

[0036] To address the problems existing in the prior art, this invention provides a fertilization method for improving the yield and quality of alfalfa in sandy soil. The method includes applying base fertilizer to the soil before planting and applying seed fertilizer at the time of alfalfa sowing. It also includes the following steps: irrigating 4 to 5 times during each alfalfa growing season, including 2 times of fertigation; during fertigation, water is applied first, and then fertilizer is added to the water before continuing irrigation; the fertilizer consists of urea, monoammonium phosphate, potassium chloride, and zinc sulfate, with a mass ratio of 1.875–4:2.875–5.6:0.875–2.4:0.2–0.36.

[0037] To improve water and fertilizer utilization efficiency, irrigation and fertilization should follow the principle of small, frequent applications. Each alfalfa harvest should be spaced 30-45 days apart, and each crop should be irrigated 4-5 times during its growth period, with each irrigation lasting 4-5 hours per acre, and each irrigation flow rate being 8 m³ / acre. 3 / h~10m 3 / h. Two of the irrigation sessions are fertigation, specifically the first and third irrigations. During fertigation, water is first applied for 2 hours per acre, then fertilizer is added to the water and evenly injected into the sprinkler or drip irrigation system. This ensures the fertilizer reaches the alfalfa roots directly, achieving precise fertilization, improving nutrient absorption efficiency, and promoting healthy alfalfa growth in sandy soil. This invention, by combining irrigation and fertilization and limiting the number of irrigations, duration, and fertilizer application for fertigation, effectively solves the problems of low yield and poor quality alfalfa in sandy soil areas of Northwest China, caused by poor water and fertilizer retention and severe water and fertilizer leakage. It also significantly reduces planting costs.

[0038] The technical solution of the present invention will be further explained and illustrated below with examples, as detailed below:

[0039] Example 1

[0040] A fertilization method for improving the yield and quality of alfalfa in sandy soil includes the following steps:

[0041] S1. Irrigation: Shallow-buried drip irrigation technology is selected. The branch pipes use PE90 flexible hoses, and the capillary pipes use embedded drip irrigation tape. The embedded drip irrigation tape is shallowly buried in the soil, with the burial depth controlled at 10cm, to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time to facilitate the even distribution of water to the plant roots.

[0042] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure it is level and well-drained; then, in conjunction with land preparation, apply 5m³ of base fertilizer per acre. 3 The amount of organic fertilizer applied is to spread it evenly on the land and mix it evenly with the sandy soil. The organic fertilizer is selected from well-rotted farmyard manure, with an organic matter content of 25%, a nitrogen content of 0.7%, a phosphorus content of 0.5%, and a potassium content of 0.4%.

[0043] S3. Seed fertilizer: When sowing alfalfa, use a seeder to apply seed fertilizer to the soil at a depth of 5cm below the seeds. Apply 5kg of urea, 7kg of monoammonium phosphate and 3kg of potassium chloride per acre.

[0044] S4. Topdressing: Irrigate 5 times during each alfalfa growing season, 4 hours each time, with a flow rate of 10m³ per irrigation. 3 / h; During the first and third irrigations of each crop, 2.5 kg of urea, 3.5 kg of monoammonium phosphate, 1.5 kg of potassium chloride, and 0.3 kg of zinc sulfate per mu were used for fertigation. Each time fertigation was carried out, the water was first irrigated for 2 hours to moisten the soil. Then, the fertilizer for fertigation was added to the fertilizer container and dissolved evenly. The fertilizer solution was then injected into the drip irrigation pipe using a fertilizer pump to continue irrigation, ensuring that the fertilizer was evenly distributed to the alfalfa root layer with the water. This group was called the fertigation optimization group, as shown in Tables 1 and 2.

[0045] Table 1. Irrigation and Fertilization Schedule for Alfalfa During its Growth Period (Example 1)

[0046]

[0047] Note: — indicates that only irrigation water is used.

[0048] Table 2. Types and amounts of fertilizer applied during the growth period of alfalfa in Example 1.

[0049]

[0050]

[0051] Note: — indicates that the amount of fertilizer applied is 0.

[0052] Example 2

[0053] A fertilization method for improving the yield and quality of alfalfa in sandy soil includes the following steps:

[0054] S1. Irrigation: Shallow-buried drip irrigation technology is selected. The branch pipes use PE90 flexible hoses, and the capillary pipes use embedded drip irrigation tape. The embedded drip irrigation tape is shallowly buried in the soil, with the burial depth controlled at 8cm, to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time to facilitate the even distribution of water to the plant roots.

[0055] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure it is level and well-drained; then, in conjunction with land preparation, apply 8m³ of base fertilizer per acre. 3 The amount of organic fertilizer applied is to spread it evenly on the land and mix it evenly with the sandy soil. The organic fertilizer is selected from well-rotted farmyard manure, with an organic matter content of 25%, a nitrogen content of 0.7%, a phosphorus content of 0.5%, and a potassium content of 0.4%.

[0056] S3. Seed fertilizer: When sowing alfalfa, use a seeder to apply seed fertilizer to the soil at a depth of 3cm below the seeds. Apply 5kg of urea, 7kg of monoammonium phosphate and 3kg of potassium chloride per acre.

[0057] S4. Topdressing: Irrigate 5 times during each alfalfa growing season, 5 hours each time, with a flow rate of 8m³ / h each time. 3 / h; During the first and third irrigations of each crop, apply 1.875 kg of urea, 2.875 kg of monoammonium phosphate, 0.875 kg of potassium chloride, and 0.2 kg of zinc sulfate per mu for fertigation. Each time, irrigate for 2 hours to moisten the soil, then add the fertigation fertilizer to the fertilizer container, dissolve it evenly, and then use a fertilizer pump to inject the fertilizer solution into the drip irrigation pipe to continue irrigation, ensuring that the fertilizer is evenly distributed to the alfalfa root layer with the water.

[0058] Example 3

[0059] A fertilization method for improving the yield and quality of alfalfa in sandy soil includes the following steps:

[0060] S1. Irrigation: Fixed sprinkler irrigation technology is adopted, with the burial depth controlled at 20cm to ensure stability. Low-angle sprinklers are installed on the vertical pipes, using plastic rocker-arm sprinklers to ensure uniform irrigation coverage.

[0061] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure it is level and well-drained; then, in conjunction with land preparation, apply 5m³ of base fertilizer per acre. 3 The amount of organic fertilizer applied is to spread it evenly on the land and mix it evenly with the sandy soil. The organic fertilizer is selected from well-rotted farmyard manure, with an organic matter content of 25%, a nitrogen content of 0.7%, a phosphorus content of 0.5%, and a potassium content of 0.4%.

[0062] S3. Seed fertilizer: When sowing alfalfa, use a seeder to apply seed fertilizer to the soil at a depth of 3cm below the seeds. Apply 5kg of urea, 7kg of monoammonium phosphate and 3kg of potassium chloride per acre.

[0063] S4. Topdressing: Irrigate 5 times during each alfalfa growing season, 4 hours each time, with a flow rate of 10m³ per irrigation. 3 / h; During the first and third irrigations of each crop, apply 4 kg of urea, 5.6 kg of monoammonium phosphate, 2.4 kg of potassium chloride, and 0.36 kg of zinc sulfate per mu for fertigation. Each time, irrigate for 2 hours to moisten the soil, then add the fertigation fertilizer to the fertilizer container, dissolve it evenly, and then use a fertilizer pump to inject the fertilizer solution into the drip irrigation pipe to continue irrigation, ensuring that the fertilizer is evenly distributed to the alfalfa root layer with the water.

[0064] Comparative Example 1

[0065] A fertilization method for increasing alfalfa yield in sandy soil includes the following steps:

[0066] S1. Irrigation: Shallow-buried drip irrigation technology is selected. The branch pipes use PE90 flexible hoses, and the capillary pipes use embedded drip irrigation tape. The embedded drip irrigation tape is shallowly buried in the soil, with the burial depth controlled at 8cm, to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time to facilitate the even distribution of water to the plant roots.

[0067] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure it is level and well-drained; then, in conjunction with land preparation, apply 8m³ of organic fertilizer per acre. 3 Apply 6 kg of urea, 8 kg of monoammonium phosphate and 4 kg of potassium chloride, spread the fertilizer evenly on the land and mix it evenly with the sandy soil.

[0068] S3. Seed fertilizer: When sowing alfalfa, use a seeder to apply seed fertilizer to the soil at a depth of 5cm below the seeds. Apply 6kg of urea, 8kg of monoammonium phosphate and 4kg of potassium chloride per acre.

[0069] S4. Topdressing: During the alfalfa's growth period, administer four irrigations using a combined water and fertilizer system. Each irrigation should apply 15% of the total fertilizer. Irrigate five times during each alfalfa crop, for four hours each time, with a flow rate of 10 m³ / h. 3 / h; During the first irrigation of each crop, add fertilizers of 4.5 kg urea, 6 kg monoammonium phosphate and 3 kg potassium chloride per mu to the fertilizer container, dissolve them evenly, and then use a fertilizer pump to inject the fertilizer solution into the irrigation pipe to continue irrigation, ensuring that the fertilizer is evenly distributed in the root layer of alfalfa with the water. This is recorded as the control group, as shown in Tables 3 and 4.

[0070] Table 3 Comparative Example 1: Irrigation and Fertilization Schedule for Alfalfa During its Growth Period

[0071]

[0072] Note: — indicates that the amount of fertilizer applied is 0.

[0073] Table 4 Comparative Example 1: Types and Amounts of Fertilizers During the Growth Period of Alfalfa

[0074]

[0075] To verify the beneficial effects of the present invention, the inventors conducted field experiments using the fertilization methods of Example 1 and Comparative Example 1 of the present invention. The experimental results are as follows:

[0076] a. Experimental process

[0077] The study area is located in Yong'an New Village, Zanggui Township, Pishan County, Hotan Prefecture, Xinjiang Uygur Autonomous Region, with geographical coordinates of 78°53′5″E, 37°19′33″N, and an altitude of up to 1200 meters. Annual precipitation is scarce, ranging from 10mm to 80mm only in the plains, indicating an extremely arid continental climate. The average annual precipitation is 48.2 mm, while the average annual evaporation is 2450 mm. The soil type is sandy soil with unique physicochemical properties: the soil pH is 8.7, slightly alkaline; the organic carbon content is rich, reaching 11.89 g / kg; the total nitrogen content is 1.29 g / kg; the contents of available nitrogen, available phosphorus, and available potassium are 2.86 mg / kg, 2.77 mg / kg, and 67.61 mg / kg, respectively, while the total phosphorus and total potassium are 0.48 g / kg and 4.11 g / kg, respectively.

[0078] The experimental field covered 200 mu, with 100 mu using the fertilization method of the control group and 100 mu using the fertilization method of the water and fertilizer optimization group. The field trial was conducted from March 15, 2022 to October 15, 2022, and was recorded as the control and water and fertilizer optimization groups, respectively.

[0079] b. Experimental Results

[0080] The collected alfalfa samples were blanched, dried, and weighed in the laboratory to obtain the hay yield. The hay was then pulverized, and 500g was taken as a sample. The crude protein, neutral detergent fiber, and acid detergent fiber contents of the alfalfa hay and fresh hay obtained from the water and fertilizer optimization group and the control group were tested using conventional testing methods. The test results are as follows: Figure 3 , Figure 4 and Figure 5 As shown.

[0081] Figure 1 This is a comparison chart showing the yield of four harvests of alfalfa hay obtained using the fertilization methods of Example 1 and Comparative Example 1 of the present invention. Figure 1 The results showed that the yields of the four crops with optimized water and fertilizer management reached 367.14 kg / mu, 339.49 kg / mu, 275.06 kg / mu, and 179.94 kg / mu, respectively, with a total yield of 1161.64 kg / mu. In contrast, the yields of the four crops in the control group were 317.31 kg / mu, 275.25 kg / mu, 226.83 kg / mu, and 147.71 kg / mu, respectively, with a total yield of 967.09 kg / mu. Compared to the control, the optimized water and fertilizer management group showed significant advantages in both the yields of the four crops and the total yield. Specifically, compared to the control, the optimized water and fertilizer management group increased the yields of the four crops by 15.71%, 23.34%, 21.27%, and 21.83%, respectively, while the total yield increased by 20.12%.

[0082] Figure 2 This is a comparison chart showing the yield of fresh alfalfa from four harvests under the fertilization methods of Example 1 and Comparative Example 1. Figure 2 The results showed that optimized water and fertilizer management resulted in yields of 1895.99 kg / mu, 1758.10 kg / mu, 1356.58 kg / mu, and 1062.10 kg / mu for the four crops, with a total yield of 6072.77 kg / mu. In contrast, the control group's yields for the four crops were 1546.21 kg / mu, 1352.32 kg / mu, 1073.47 kg / mu, and 802.99 kg / mu, with a total yield of 4774.98 kg / mu. Compared to the control, optimized water and fertilizer management demonstrated significant advantages in both crop yield and total yield. Specifically, compared to the control, optimized water and fertilizer management increased the yields for the four crops by 22.62%, 30.01%, 26.37%, and 32.27%, respectively, while the total yield increased by 27.18%.

[0083] Figure 3 This is a comparison chart showing the crude protein content of four harvests of alfalfa hay obtained using the fertilization methods of Example 1 and Comparative Example 1. Figure 3 The results, as shown in the figure, indicate that optimized water and fertilizer management resulted in crude protein levels of 21.98%, 19.79%, 19.09%, and 19.20% in the four hay crops, respectively, with an average crude protein content of 20.02%. In contrast, the control crop yields were 21.04%, 18.22%, 17.46%, and 17.75%, respectively, with an average crude protein content of 18.62%. Compared to the control, optimized water and fertilizer management demonstrated a significant advantage in crude protein content across all four hay crops. Specifically, compared to the control, optimized water and fertilizer management increased the crude protein content of the four hay crops by 4.5%, 8.7%, 9.4%, and 8.1%, respectively, while the average protein content increased by 7.5%.

[0084] Figure 4 This is a comparison chart showing the acid detergent fiber content of four harvests of alfalfa hay from the fertilization methods of Example 1 and Comparative Example 1. Figure 4 The results showed that water and fertilizer optimization achieved neutral detergent fiber (NDF) levels of 37.22%, 37.53%, 38.14%, and 38.67% in the four haystacks, respectively, with an average NDF content of 37.89%. In contrast, the control group's NDF levels were 38.97%, 38.41%, 38.89%, and 39.97%, respectively, with an average of 39.06%. Compared to the control, water and fertilizer optimization demonstrated a significant advantage in NDF content across all four haystacks. Specifically, water and fertilizer optimization reduced NDF content by 4.5%, 2.3%, 1.9%, and 3.3% in the four haystacks, respectively, and the average NDF content was reduced by 3.0%.

[0085] Figure 5 This is a comparison chart showing the acid detergent fiber content of four harvests of alfalfa fresh grass from the fertilization methods of Example 1 and Comparative Example 1. Figure 5The results showed that water and fertilizer optimization achieved acid detergent fiber (ADF) levels of 29.53%, 28.97%, 30.33%, and 30.63% in the four haystacks, respectively, with an average ADF content of 29.87%. In contrast, the control group's ADF levels were 31.40%, 30.73%, 31.47%, and 32.00%, respectively, with an average of 31.40%. Compared to the control, water and fertilizer optimization demonstrated a significant advantage in ADF content across all four haystacks. Specifically, water and fertilizer optimization reduced ADF content by 5.9%, 5.7%, 3.6%, and 4.3% in the four haystacks, respectively, with an average reduction of 4.9%.

[0086] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0087] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fertilization method for improving the yield and quality of alfalfa in sandy soil, comprising applying base fertilizer to the soil before planting and applying seed fertilizer at the time of alfalfa sowing, characterized in that, It also includes the following steps: Each crop of alfalfa is irrigated 4 to 5 times during its growth period, including 2 times of fertigation. When carrying out integrated water and fertilizer irrigation, first irrigate with water, and then add fertilizer to the water to continue irrigation; The fertilizer is composed of urea, monoammonium phosphate, potassium chloride, and zinc sulfate, and the mass ratio of urea, monoammonium phosphate, potassium chloride, and zinc sulfate is 1.875~4:2.875~5.6:0.875~2.4:0.2~0.

36. The total amount of fertilizer used during the growth period of alfalfa is as follows: urea 15 kg / mu to 20 kg / mu, monoammonium phosphate 23 kg / mu to 28 kg / mu, potassium chloride 7 kg / mu to 12 kg / mu and zinc sulfate 2 kg / mu to 3 kg / mu; The two irrigations, which combine water and fertilizer, are carried out during the first and third irrigations during the growth period of each crop of alfalfa. Each irrigation lasts 4-5 hours per acre, with a flow rate of 8 m³ / acre. 3 / h~10m 3 / h; The procedure for each fertigation irrigation is as follows: first, irrigate with water for 2 hours per acre, then add fertilizer to the water and continue irrigating for another 2 to 3 hours per acre, with a flow rate of 8 m³ / acre per irrigation. 3 / h~10m 3 / h; The base fertilizer is organic fertilizer, selected from well-rotted farmyard manure, with an organic matter content ≥25%, nitrogen content ≥0.7%, phosphorus content ≥0.5%, and potassium content ≥0.4%. The application rate of organic fertilizer is 5m³. 3 / mu~8m 3 / mu.

2. The fertilization method for improving the yield and quality of alfalfa in sandy soil according to claim 1, characterized in that, Irrigation is carried out using drip irrigation or sprinkler irrigation.

3. The fertilization method for improving the yield and quality of alfalfa in sandy soil according to claim 2, characterized in that, The drip irrigation system uses shallow-buried drip irrigation, with the drip irrigation pipes buried 8cm to 10cm below the surface.

4. The fertilization method for improving the yield and quality of alfalfa in sandy soil according to claim 2, characterized in that, The sprinkler system uses a semi-fixed sprinkler system. The vertical pipes of the semi-fixed sprinkler system use low-angle nozzles, and the branch pipes of the semi-fixed sprinkler system are buried 15cm to 20cm below the ground surface.

5. The fertilization method for improving the yield and quality of alfalfa in sandy soil according to claim 1, characterized in that, The seed fertilizer consists of urea, monoammonium phosphate and potassium chloride. The total amount of seed fertilizer used is: 3 kg / mu to 5 kg / mu of urea, 5 kg / mu to 7 kg / mu of monoammonium phosphate and 3 kg / mu to 5 kg / mu of potassium chloride.

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