Fertilizing method for improving yield and quality of alfalfa in sandy soil

Abstract

The invention belongs to the technical field of plant cultivation, and particularly relates to a fertilizing method for improving the yield and quality of alfalfa in sandy soil. The fertilizing method comprises the following steps: applying a base fertilizer in soil before planting, and applying a seed fertilizer when alfalfa is sown, and further comprises the following steps: irrigating for 4-5 times during the growth period of each crop of alfalfa, two times of irrigation being water and fertilizer integrated irrigation; when water and fertilizer integrated irrigation is carried out, water is firstly irrigated, and then a fertilizer is added into the water for continuous irrigation; the fertilizer is prepared from urea, monoammonium phosphate, potassium chloride and zinc sulfate, and the mass ratio of the urea to the monoammonium phosphate to the potassium chloride to the zinc sulfate is (1.875 to 4) to (2.875 to 5.6) to (0.875 to 2.4) to (0.2 to 0.36). The method not only solves the problems of low yield and poor quality of alfalfa caused by poor water and fertilizer retention capability and serious water and fertilizer leakage of sandy soil in pasture fields for planting alfalfa in northwest sandy soil areas, but also remarkably reduces the planting cost.

Description

Technical Field

[0001] The invention belongs to the technical field of plant cultivation, and in particular relates to a fertilization method for improving the yield and quality of alfalfa in sandy soil. Background Art

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

[0003] However, as a high-water-consuming plant, the growth characteristics of alfalfa are significantly different from those of traditional annual crops such as cotton, wheat, and corn in terms of production methods, water-saving irrigation, and fertilization techniques. These crops have different characteristics in terms of growth cycle, water demand, and nutrient absorption. Therefore, there are also different strategies for planting and management. However, when farmers and herdsmen plant alfalfa, they often follow the planting methods of wheat and corn, ignoring the special needs of alfalfa, which restricts the improvement of its yield and quality. Especially in the sandy areas of the northwest, due to the special geographical environment, soil barrier factors, water and heat resource limitations, and terrain conditions, the water and fertilizer retention capacity of these lands is weak, which directly affects the growth environment and agricultural production capacity of alfalfa. In addition, due to the poor water and fertilizer retention performance of sandy soil, even if farmers and herdsmen put in a lot of fertilizer, they cannot guarantee that alfalfa can be fully absorbed and utilized, resulting in low fertilizer utilization and increased planting costs. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a fertilization method for improving the yield and quality of alfalfa in sandy soil. By reasonably combining irrigation and fertilization, limiting the number of water-fertilizer integrated irrigations and irrigation time as well as the number of fertilizations, fertilization time and fertilizer amount, it not only effectively solves the problems of low alfalfa yield and poor quality caused by poor water and fertilizer retention capacity of sandy soil in alfalfa forage fields in the sandy land areas of Northwest China and serious water and fertilizer leakage, but also significantly reduces the planting cost.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

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

[0007] Combine irrigation with fertilization. Irrigate 4 to 5 times during the growth period of each crop of alfalfa, 2 of which are integrated water and fertilizer irrigations. Alfalfa can be mowed 4 times during its growth period, for a total of 8 topdressing irrigations.

[0008] When carrying out integrated water-fertilizer irrigation, irrigate water first, then add fertilizer to the water and continue irrigation.

[0009] 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.

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

[0011] Preferably, 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 after each crop is mowed, and combining irrigation and fertilization at this time can significantly increase the regeneration rate of alfalfa, which makes an important contribution to the later yield.

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

[0013] Preferably, the operation of each water-fertilizer integrated irrigation is: first irrigate with water for 2 hours per mu, then add fertilizer to the water and continue to irrigate for 2 hours per mu to 3 hours per mu, and the flow rate of each irrigation is 8m 3 / h~10m 3 / h.

[0014] Preferably, each time the water-fertilizer is irrigated, water is first irrigated for 2 hours per mu, and then the fertilizer is added to the fertilization container, and after being fully stirred and dissolved evenly, it is injected into the irrigation pipe using a water-fertilizer integrated device, such as a fertilizer pump, and irrigation is continued for 2 hours per mu to 3 hours per mu, and the flow rate of each irrigation is 8m 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, the branch pipe adopts PE90 hose, the capillary tube adopts embedded sheet drip irrigation belt, and the branch pipe is buried below 8cm to 10cm in the surface layer.

[0017] Preferably, the sprinkler irrigation adopts semi-fixed sprinkler irrigation technology, the vertical pipe of the semi-fixed sprinkler irrigation adopts a low-elevation angle sprinkler head, and the branch pipe of the semi-fixed sprinkler irrigation is buried below 15cm to 20cm of the surface layer.

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

[0019] Preferably, the base fertilizer is applied in combination with land preparation before planting alfalfa. The base fertilizer is organic fertilizer, which is selected from decomposed farmyard manure with an organic matter content of ≥25%, N content of ≥0.7%, P content of ≥0.5%, and K content of ≥0.4%. The amount of organic fertilizer applied is 5m 3 / mu~8m 3 / mu.

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

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

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention provides a fertilization method for improving the yield and quality of alfalfa in sandy soil. By combining irrigation with fertilization and limiting the number, time and amount of fertilizer for integrated water-fertilizer irrigation, the present invention not only effectively solves the problems of low yield and poor quality caused by poor water and fertilizer retention capacity of sandy soil in alfalfa forage fields in the sandy soil areas of Northwest China and serious water and fertilizer leakage, but also significantly reduces the planting cost.

[0024] a. Determine the number of fertilizations: Alfalfa can only regenerate if it is irrigated immediately after each crop is cut. Therefore, the combination of the first irrigation and fertilization after each crop can significantly increase the regeneration rate of alfalfa, which is an important contribution to the accumulation of later yields. However, too many fertilizations will increase the production and management costs of alfalfa. Therefore, it is determined that fertilization should be carried out during the first and third irrigations after each crop is cut, which has the most significant effect on increasing alfalfa yield.

[0025] b. Determination of fertilization time: In order to improve the efficiency of water and fertilizer utilization, irrigation and fertilization follow the principle of small amounts and multiple times, that is, the growth period of each crop of alfalfa is 30 to 45 days, and each crop of alfalfa is watered 4 to 5 times during the growth period, each irrigation time is 4 hours / mu to 5 hours / mu, and the flow rate of each irrigation is 8m 3 / h~10m 3 / h to ensure that alfalfa gets enough water during its growth; there are two irrigations of water-fertilizer integration, namely the first and third irrigations. Each time of water-fertilizer integration irrigation, sprinkle or drip irrigation water for 2h / mu, then add the fertilizer for water-fertilizer integration irrigation into the fertilizer container, and after dissolving evenly, use the water-fertilizer integration equipment to inject it into the sprinkler or drip irrigation pipe to continue irrigation, so that the fertilizer can enter the alfalfa root layer with the sprinkler or drip irrigation water, which has the best effect.

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

[0027] 2. The present invention provides a fertilization method for improving the yield and quality of alfalfa in sandy soil. Compared with the prior art, i.e., comparative example 1, under the same plot conditions, the present invention can still increase the annual total output value of alfalfa hay when the amount of fertilizer applied is reduced. Among them, when the total amount of urea, monoammonium phosphate and potassium chloride is reduced by 14%, the annual total output of alfalfa is still increased by 20.12%. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The figure is a comparison chart of the yield of four crops of alfalfa hay harvested by the fertilization method of Example 1 of the present invention and Comparative Example 1.

[0029] Figure 2 The figure is a comparison chart of the fresh grass yield of alfalfa harvested from four crops by the fertilization methods of Example 1 of the present invention and Comparative Example 1.

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

[0031] Figure 4 This is a comparison chart of the acid detergent fiber content of four crops of alfalfa hay harvested by the fertilization method of Example 1 of the present invention and Comparative Example 1.

[0032] Figure 5 This is a comparison chart of the acid detergent fiber content of fresh alfalfa harvested from four crops using the fertilization methods of Example 1 of the present invention and Comparative Example 1. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in combination with the data in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that the professional terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, the various fertilizers and equipment used in the following embodiments of the present invention can be purchased on the market.

[0035] At present, farmers and herdsmen still use the planting methods of traditional crops such as wheat and corn when planting alfalfa, ignoring the special needs of alfalfa as forage, which restricts the effective improvement of alfalfa yield and quality. In addition, the main problem faced by planting alfalfa forage in the sandy areas of the northwest is that the natural characteristics of the sand limit its ability to retain water and fertilizer, resulting in a significant weakening of the irrigation and fertilization effects; and because water and nutrients can easily be lost quickly through the cracks in the sand, it is difficult for the alfalfa root system to effectively absorb and utilize them. This rapid loss of water and fertilizer resources not only increases the cost of planting, but also seriously hinders the normal growth of alfalfa, resulting in low yields and difficult to ensure quality.

[0036] In view of the problems existing in the prior art, the present invention provides a fertilization method for improving the yield and quality of alfalfa in sandy soil, comprising applying basal fertilizer to the soil before planting and applying seed fertilizer when sowing alfalfa, and also comprising the following steps: irrigating 4 to 5 times during the growth period of each crop of alfalfa, of which 2 times are water-fertilizer integrated irrigation; when performing water-fertilizer integrated irrigation, irrigating water first, and then adding fertilizer to the water to continue 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.

[0037] In order to improve the efficiency of water and fertilizer utilization, irrigation and fertilization follow the principle of small amounts and multiple times. The interval between each crop of alfalfa mowing is 30 to 45 days, and each crop of alfalfa is watered 4 to 5 times during its growth period. Each irrigation lasts 4 to 5 hours per mu, and the flow rate of each irrigation is 8m 3 / h~10m 3 / h. Among them, 2 times are water-fertilizer integrated irrigation, that is, water-fertilizer integrated irrigation is carried out during the first irrigation and the third irrigation; when performing water-fertilizer integrated irrigation, first irrigate water for 2h / mu, then add fertilizer to the water, and evenly inject it into the sprinkler or drip irrigation pipe through the water-fertilizer integrated equipment to continue irrigation, so that the fertilizer can reach the roots of alfalfa with the water, realize precise fertilization, improve nutrient absorption efficiency, and promote the healthy growth of alfalfa in sandy soil. The present invention combines irrigation with fertilization, and limits the irrigation frequency, time and fertilizer dosage of water-fertilizer integrated irrigation. It not only effectively solves the problem of low alfalfa yield and poor quality caused by poor water and fertilizer retention capacity of sandy soil in alfalfa forage fields planted in the sandy land areas of Northwest China, and serious water and fertilizer leakage, but also can significantly reduce the planting cost.

[0038] The technical solution of the present invention is further explained by using embodiments below, which are specifically as follows:

[0039] Example 1

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

[0041] S1. Irrigation: Choose shallow buried drip irrigation technology, use PE90 hose for branch pipes, and use embedded drip irrigation tape for capillary pipes. The embedded drip irrigation tape is shallowly buried in the soil, with a depth of 10cm to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time, it is conducive to evenly distributing water to the roots of plants.

[0042] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure that it is flat and well-drained; then, combine land preparation with 5m per mu. 3 The organic fertilizer is evenly spread on the land and mixed evenly with the sandy soil; wherein the organic fertilizer is selected from decomposed farmyard manure, with an organic matter content of 25%, a N element content of 0.7%, a P element content of 0.5%, and a K element content of 0.4%.

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

[0044] S4. Topdressing: During the growth period of each crop of alfalfa, irrigate 5 times, each time for 4 hours, and the flow rate of each irrigation is 10m 3 / h; during the first and third irrigations of each crop, 2.5kg of urea, 3.5kg of monoammonium phosphate, 1.5kg of potassium chloride and 0.3kg of zinc sulfate per mu of water and fertilizer were used for integrated irrigation. Each time the water and fertilizer were irrigated, water was irrigated for 2h to moisten the soil, and then the fertilizer for the integrated irrigation was added to the fertilizer container. After dissolving evenly, the fertilizer solution was injected into the drip irrigation pipe with a fertilizer pump for continued irrigation to ensure that the fertilizer was evenly distributed to the root layer of alfalfa with the water. This was recorded as the water and fertilizer optimization group, as shown in Tables 1 and 2.

[0045] Table 1 Example 1 Irrigation and fertilization schedule during the growth period of alfalfa

[0046]

[0047] Note: - indicates irrigation water only.

[0048] Table 2 Example 1 Alfalfa growth period fertilizer type and fertilizer amount table

[0049]

[0050]

[0051] Note: — indicates 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 comprises the following steps:

[0054] S1. Irrigation: Choose shallow buried drip irrigation technology, use PE90 hose for branch pipes, and use embedded drip irrigation tape for capillary pipes. The embedded drip irrigation tape is shallowly buried in the soil, with a depth of 8cm to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time, it is conducive to evenly distributing water to the roots of plants.

[0055] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure that it is flat and well-drained; then, combine land preparation with 8m per mu. 3 The organic fertilizer is evenly spread on the land and mixed evenly with the sandy soil; wherein the organic fertilizer is selected from decomposed farmyard manure, with an organic matter content of 25%, a N element content of 0.7%, a P element content of 0.5%, and a K element content of 0.4%.

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

[0057] S4. Topdressing: During the growth period of each crop of alfalfa, irrigate 5 times, each time for 5 hours, and the flow rate of each irrigation is 8m 3 / h; during the first and third irrigations of each crop, 1.875kg of urea, 2.875kg of monoammonium phosphate, 0.875kg of potassium chloride and 0.2kg of zinc sulfate per mu of water and fertilizer are used for integrated irrigation. Each time water and fertilizer are irrigated, water is irrigated for 2 hours to moisten the soil, and then the fertilizer for integrated irrigation is added to the fertilizer container. After dissolving evenly, the fertilizer solution is injected into the drip irrigation pipe with a fertilizer pump for continued irrigation to ensure that the fertilizer is evenly distributed to the root layer of alfalfa with the water.

[0058] Example 3

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

[0060] S1. Irrigation: Fixed sprinkler technology is used, and the burial depth is controlled at 20cm to ensure stability. The vertical pipe is installed with a low-angle sprinkler, and a plastic rocker-arm sprinkler is used to ensure uniform sprinkler coverage.

[0061] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure that it is flat and well-drained; then, combine land preparation with 5m per mu. 3 The organic fertilizer is evenly spread on the land and mixed evenly with the sandy soil; wherein the organic fertilizer is selected from decomposed farmyard manure, with an organic matter content of 25%, a N element content of 0.7%, a P element content of 0.5%, and a K element content of 0.4%.

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

[0063] S4. Topdressing: During the growth period of each crop of alfalfa, irrigate 5 times, each time for 4 hours, and the flow rate of each irrigation is 10m 3 / h; during the first and third irrigations of each crop, 4kg of urea, 5.6kg of monoammonium phosphate, 2.4kg of potassium chloride and 0.36kg of zinc sulfate per mu of water and fertilizer are used for integrated irrigation. Each time water and fertilizer are used for integrated irrigation, water is irrigated for 2 hours to moisten the soil, and then the fertilizer for integrated irrigation is added to the fertilizer container. After dissolving evenly, the fertilizer solution is injected into the drip irrigation pipe with a fertilizer pump for continued irrigation to ensure that the fertilizer is evenly distributed to the root layer of alfalfa with the water.

[0064] Comparative Example 1

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

[0066] S1. Irrigation: Choose shallow buried drip irrigation technology, use PE90 hose for branch pipes, and use embedded drip irrigation tape for capillary pipes. The embedded drip irrigation tape is shallowly buried in the soil, with a depth of 8cm to ensure that the embedded drip irrigation tape is not damaged by farming tools, and at the same time, it is conducive to evenly distributing water to the roots of plants.

[0067] S2. Base fertilizer: Before planting alfalfa, prepare the land to ensure that it is flat and well-drained; then, combine land preparation with 8m3 of organic fertilizer per mu. 3 , 6kg of urea, 8kg of monoammonium phosphate and 4kg 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 5 cm below the seeds. Apply 6 kg of urea, 8 kg of monoammonium phosphate, and 4 kg of potassium chloride per mu of land.

[0069] S4. Topdressing: During the growth period of alfalfa, four irrigations with integrated water and fertilizer are carried out. The amount of fertilizer in each irrigation accounts for 15% of the total amount of fertilizer. During the growth period of each crop of alfalfa, irrigation is carried out five times, each time for 4 hours, and the flow rate of each irrigation is 10m 3 / h; at the first watering of each crop, add fertilizers into the fertilizer container at the amount of 4.5kg urea, 6kg monoammonium phosphate and 3kg potassium chloride per mu. After dissolving evenly, use a fertilizer pump to inject the fertilizer solution into the irrigation pipe and continue irrigation to ensure 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 for irrigation and fertilization schedule during the growth period of alfalfa

[0071]

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

[0073] Table 4 Comparative Example 1 Fertilizer Type and Fertilizer Quantity during the Growth Period of Alfalfa

[0074]

[0075] In order 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, and the experimental results are as follows:

[0076] a. Test process

[0077] The study area is located in Yong'an New Village, Zanggui Township, Pishan County, Hotan Prefecture, Xinjiang Uygur Autonomous Region. Its geographical coordinates are 78°53′5″E east longitude and 37°19′33″N north latitude. It is 1,200 meters above sea level. The average annual precipitation is scarce, only 10mm to 80mm in the plain area. It has an extremely dry continental climate; the average annual precipitation is 48.2 mm, and the average annual evaporation is 2,450 mm. The soil type is sandy soil with unique physical and chemical properties: the soil pH is 8.7, which is alkaline; the organic carbon content is rich, reaching 11.89g / kg; the total nitrogen content is 1.29g / kg; the contents of alkaline nitrogen, available phosphorus and available potassium are 2.86mg / kg, 2.77mg / kg and 67.61mg / kg respectively, and the total phosphorus and total potassium are 0.48g / kg and 4.11g / kg respectively.

[0078] The experimental site covers an area of ​​200 mu, of which 100 mu adopted the fertilization method of the control group and 100 mu adopted the fertilization method of the water-fertilizer optimization group. Field trials were carried out from March 15, 2022 to October 15, 2022, and were recorded as control and water-fertilizer optimization, respectively.

[0079] b. Experimental results

[0080] The collected alfalfa samples were sterilized, dried, and weighed in the laboratory to obtain the hay yield, which was then crushed and 500 g was taken as a sample. The crude protein, neutral detergent fiber content, and acid detergent fiber content of the alfalfa hay and fresh grass obtained from the water-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 shown.

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

[0082] Figure 2 This is a comparison chart of the fresh grass yield of four crops of alfalfa harvested by the fertilization method of Example 1 and Comparative Example 1. Figure 2 The results showed that the water and fertilizer optimization achieved 1895.99kg / mu, 1758.10kg / mu, 1356.58kg / mu, 1062.10kg / mu, and a total yield of 6072.77kg / mu in the four crops. The four yields of the control were 1546.21kg / mu, 1352.32kg / mu, 1073.47kg / mu, and 802.99kg / mu, with a total yield of 4774.98kg / mu. Compared with the control, water and fertilizer optimization showed significant advantages in both the four-crop yield and the total yield. Specifically, compared with the control, the water and fertilizer optimization increased the yield of the four crops by 22.62%, 30.01%, 26.37%, and 32.27%, respectively, and the total yield increased by 27.18%.

[0083] Figure 3 This is a comparison chart of crude protein content of four crops of alfalfa hay harvested by the fertilization method of Example 1 and Comparative Example 1. Figure 3 The results show that the optimization of water and fertilizer has achieved 21.98%, 19.79%, 19.09%, and 19.20% crude protein in the four crops of hay, respectively, with an average crude protein of 20.02%. The four yields of the control were 21.04%, 18.22%, 17.46%, and 17.75%, respectively, with an average crude protein of 18.62%. Compared with the control, the optimization of water and fertilizer showed a significant advantage in the crude protein content of the four crops of hay. Specifically, compared with the control, the optimization of water and fertilizer increased the crude protein content of the four crops of hay by 4.5%, 8.7%, 9.4%, and 8.1%, respectively, and the average protein content increased by 7.5%.

[0084] Figure 4 This is a comparison chart of the acid detergent fiber content of four crops of alfalfa hay harvested by the fertilization method of Example 1 and Comparative Example 1. Figure 4 The results showed that the water-fertilizer optimization achieved 37.22%, 37.53%, 38.14%, and 38.67% in the neutral detergent fiber of the four hay crops, respectively, and the average neutral detergent fiber was 37.89%. The neutral detergent fiber of the four hay crops of the control was 38.97%, 38.41%, 38.89%, and 39.97%, respectively, and the average neutral detergent fiber was 39.06%. Compared with the control, water-fertilizer optimization showed significant advantages in the neutral detergent fiber content of the four hay crops. Specifically, compared with the control, the water-fertilizer optimization reduced the neutral detergent fiber content of the four hay crops by 4.5%, 2.3%, 1.9%, and 3.3%, respectively, and the average neutral detergent fiber content was reduced by 3.0%.

[0085] Figure 5 This is a comparison chart of the acid detergent fiber content of four crops of fresh alfalfa harvested by the fertilization method of Example 1 and Comparative Example 1. Figure 5The results showed that the water-fertilizer optimization achieved 29.53%, 28.97%, 30.33%, and 30.63% acid detergent fiber in the four hay crops, respectively, and the average acid detergent fiber was 29.87%. The acid detergent fiber of the four hay crops of the control was 31.40%, 30.73%, 31.47%, and 32.00%, respectively, and the average acid detergent fiber was 31.40%. Compared with the control, water-fertilizer optimization showed significant advantages in the acid detergent fiber content of the four hay crops. Specifically, compared with the control, the water-fertilizer optimization reduced the acid detergent fiber content of the four hay crops by 5.9%, 5.7%, 3.6%, and 4.3%, respectively, and the average acid detergent fiber content was reduced by 4.9%.

[0086] It should be noted that when the present invention involves a numerical range, it should be understood that the two 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 those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0087] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A fertilization method for improving the yield and quality of alfalfa in sandy soil, comprising applying basal fertilizer to the soil before planting and applying seed fertilizer when sowing alfalfa, characterized in that: The following steps are also included: Each crop of alfalfa is irrigated 4 to 5 times during its growth period, 2 of which are water-fertilizer integrated irrigations; When carrying out water-fertilizer integrated irrigation, water is first irrigated, and then fertilizer is added to the water and continued 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.

2. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: The total amount of the fertilizers used during the growth period of alfalfa is: 15kg / mu to 20kg / mu of urea, 23kg / mu to 28kg / mu of monoammonium phosphate, 7kg / mu to 12kg / mu of potassium chloride and 2kg / mu to 3kg / mu of zinc sulfate.

3. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: Two irrigations of integrated water and fertilizer were carried out during the first and third irrigations during the growth period of each crop of alfalfa.

4. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: Each irrigation lasts 4h / mu to 5h / mu, and the flow rate of each irrigation is 8m 3 / h~10m 3 / h.

5. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: The operation of each water-fertilizer integrated irrigation is: first irrigate with water for 2 hours / mu, then add fertilizer to the water and continue to irrigate for 2 hours / mu to 3 hours / mu, and the flow rate of each irrigation is 8m 3 / h~10m 3 / h.

6. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: Irrigation is by drip irrigation or sprinkler irrigation.

7. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 6, characterized in that: Drip irrigation adopts shallow buried drip irrigation, and the drip irrigation pipe is buried 8cm to 10cm below the surface.

8. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 6, characterized in that: The sprinkler irrigation adopts semi-fixed sprinkler irrigation. The vertical pipe of the semi-fixed sprinkler irrigation adopts a low-angle sprinkler head, and the branch pipe of the semi-fixed sprinkler irrigation is buried 15cm to 20cm below the surface.

9. A fertilization method for improving alfalfa yield and quality in sandy soil according to claim 1, characterized in that: The base fertilizer is organic fertilizer, which is selected from decomposed farmyard manure, with an organic matter content of ≥25%, N element content of ≥0.7%, P element content of ≥0.5%, and K element content of ≥0.4%. The amount of organic fertilizer applied is 5m 3 / mu~8m 3 / mu.

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

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