Irrigation method for improving yield of alfalfa under water deficit
By arranging and alternating two sets of underground drip irrigation systems, the problem of difficult water transport for alfalfa irrigation in water-scarce areas has been solved, resulting in high yields of alfalfa, especially significantly increasing yields under drought conditions.
Patent Information
- Application Number
- CN202511727170.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-24
- Publication Date
- 2026-01-02
AI Technical Summary
In water-scarce regions, the spacing between underground drip irrigation systems for alfalfa is too large, making it difficult for irrigation water to move effectively and affecting yield.
Two underground drip irrigation systems are arranged in a cross pattern and used alternately. Combined with appropriate irrigation regimes and sowing methods, this ensures that water is evenly distributed in time and space, reducing unnecessary water consumption.
It increased the yield of alfalfa, especially under water deficit conditions, significantly improving yield. It solved the problem of water transport in space and achieved a heterogeneous wetting process of drought and re-wetting in time, increasing plant nutrient absorption.
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Figure CN121241881A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of agriculture, in particular to a method for improving the yield of alfalfa under water deficit. BACKGROUND
[0002] Agriculture is the largest water user in China. According to the data of the Water Resources Bulletin of the Ministry of Water Resources in 2024, farmland irrigation water accounts for 61.6% of the total water consumption. Irrigation areas produce 75% of the country's grain and 80% of the country's alfalfa and other forage grasses with less than half of the country's cultivated land, which is an important base for food security and an important basic water unit for agricultural water resource management.
[0003] Alfalfa is a kind of excellent forage grass, and its demand in the domestic market has been steadily increasing in recent years. In order to meet this demand, more than 1.7 million tons are imported annually. More than 4 million hectares of alfalfa are planted in the northern region of China, which is the main production area of alfalfa. These places provide suitable climate and soil conditions for alfalfa cultivation. However, in these areas with little rainfall, water scarcity is the main factor restricting the sustainable development of alfalfa production. Therefore, large-area water-saving irrigation methods, including underground drip irrigation, are widely used in alfalfa production. Underground drip irrigation accurately transports irrigation water to plant roots and plays an important role in improving crop yield. However, in actual layout, the spacing between two drip irrigation pipes is usually large, and only by increasing the amount of irrigation water can all the water be transported to the plant root zone. This will inevitably deviate from the original intention of implementing water-saving irrigation.
[0004] Therefore, there is an urgent need to develop a simple and low-cost alfalfa irrigation method to provide an effective way for water-saving and yield-increasing of alfalfa. SUMMARY
[0005] In order to solve the problem of water scarcity in areas with large spacing between underground drip irrigation systems for alfalfa, which makes it difficult for irrigation water to migrate and thus affects alfalfa yield, the present application provides a method for improving the yield of alfalfa under water deficit, which is as follows:
[0006] The present application provides a method for improving the yield of alfalfa under water deficit, which comprises using a system consisting of underground drip irrigation system 1, underground drip irrigation system 2, main pipe 1, main pipe 2, switch valve 1 and switch valve 2 during irrigation.
[0007] In the method of the present application, as one of the embodiments, the underground drip irrigation system 1 and the underground drip irrigation system 2 are arranged in the irrigation area in a cross manner, independently of each other and without affecting each other.
[0008] In the method of the present application, as one of the embodiments, the method further comprises alternatingly using the underground drip irrigation system 1 and the underground drip irrigation system 2 during irrigation.
[0009] In the method, as one of the embodiments, the method further comprises that the underground drip irrigation system 1 or the underground drip irrigation system 2 adopts a laying mode of “one pipe four”, and one drip irrigation belt pipe is used for four rows of alfalfa.
[0010] In the method, as one of the embodiments, the method further comprises that the underground drip irrigation system 1 and the underground drip irrigation system 2 are laid at intervals of 20-60 cm, preferably 40 cm.
[0011] In the method, as one of the embodiments, the method further comprises that the underground drip irrigation system 1 and the underground drip irrigation system 2 are buried at a depth of 10-30 cm underground, preferably 20 cm.
[0012] In the method, as one of the embodiments, the method further comprises that the underground drip irrigation system 1 and the underground drip irrigation system 2 are buried drip irrigation belts, the diameter is 16 mm, the distance between the drippers is 10-40 cm, preferably 30 cm, and the flow rate is 1-5 L / h, preferably 3 L / h.
[0013] In the method, as one of the embodiments, the method further comprises that the diameters of the main pipes 1 and 2 are selected according to the size of the controlled area, and the diameter of the main pipe should be greater than the diameter of the drip irrigation belt, which is 16 mm, and the diameter of the main pipe is selected to be 32-72 mm, preferably 32 mm.
[0014] In the method, as one of the embodiments, the method further comprises that the main pipes 1 and 2 realize the opening and closing of the underground drip irrigation system through electromagnetic valves or manual valves.
[0015] In the method, as one of the embodiments, the method further comprises that the switch valve 1 controls the entire underground drip irrigation system 1 and the main pipe 1, and the switch valve 2 controls the entire underground drip irrigation system 2 and the main pipe 2.
[0016] In the method, as one of the embodiments, the method further comprises that the row spacing of alfalfa is 10-30 cm, preferably 20 cm, the seeding amount is 10-30 kg / ha, preferably 20 kg / ha, and the strip seeding is performed at a seeding depth of 2-5 cm.
[0017] In the method, as one of the embodiments, the method further comprises that the alfalfa is subjected to water deficit irrigation during the branching period, the irrigation amount is calculated according to the actual crop evapotranspiration, the moderate and severe water deficit are 2 / 3 and 1 / 3 of the actual crop evapotranspiration respectively, and the irrigation frequency is once a week.
[0018] The application provides an irrigation method for improving the yield of alfalfa under water deficit.
[0019] This invention innovatively arranges two sets of underground drip irrigation systems in a cross pattern, using two sets of underground drip irrigation systems during two irrigations. This creates a dry-then-wet process in the soil over time. This heterogeneous water wetting process not only increases the absorption of plant nutrients, but also solves the problem of increasing the amount of irrigation required to transport water to the alfalfa root layer, which is far from the drip irrigation strip. This not only reduces the excess water consumption caused by water transport in space, but also increases the yield of alfalfa. Attached Figure Description
[0020] Figure 1 This is a diagram showing the layout of conventional and alternating underground drip irrigation systems according to the present invention;
[0021] Figure 2 This is a schematic diagram of conventional underground drip irrigation and alternating underground drip irrigation according to the present invention;
[0022] Figure 3 The annual yield of alfalfa under the implementation of this invention;
[0023] Figure 4 This refers to the yield of alfalfa per crop under the implementation of this invention;
[0024] The symbols in the diagram represent:
[0025] 1. An underground drip irrigation system 1 controlled by a solenoid valve or a manual valve 1; 2. An underground drip irrigation system 2 controlled by a solenoid valve or a manual valve 2. Detailed Implementation
[0026] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following embodiments are used to illustrate the present invention, but do not limit the scope of the present invention.
[0027] 1. Overview of the experimental field
[0028] The experimental site is located at the Wuwei Oasis Agricultural Efficient Water Use National Field Scientific Observation and Research Station in Gansu Province (35°52′N, 102°50′E). The site has a typical temperate continental climate, with an average annual sunshine duration exceeding 3000 hours, an average annual temperature of 8℃, an annual accumulated temperature exceeding 3350℃, an average annual water surface evaporation of 2000 mm, and an average annual precipitation of 164 mm. The soil type at the experimental site is sandy loam, with a field water holding capacity of 0.39 cm³. 3 / cm 3 The wilting point was 0.09cm. 3 / cm 3 The soil bulk density at a depth of 160cm is 1.5g / cm³. 3 During the experiment, a meteorological monitoring system located 20m from the site automatically recorded net radiation, air temperature, relative humidity, wind speed, and precipitation at a height of 2m. The precipitation in the first and second growing seasons was 109mm and 192mm, respectively.
[0029] 2. Irrigation system
[0030] To implement alternate subsurface drip irrigation of alfalfa, two sets of subsurface drip irrigation systems were designed and installed in the experimental plot. The drip irrigation tape was buried 20 cm below the ground before alfalfa was sown, and a flow meter was installed on the main pipe in the experimental area for detecting the amount of irrigation water. In designing the subsurface drip irrigation system, the conventional subsurface drip irrigation tape spacing was 80 cm, and the alternate subsurface drip irrigation tape spacing was 40 cm. Figure 1 The conventional subsurface drip irrigation and alternate subsurface drip irrigation layout is shown, including subsurface drip irrigation system 1, subsurface drip irrigation system 2, main pipe 1, main pipe 2, on-off valve 1, and on-off valve 2. On-off valve 1 controls the entire subsurface drip irrigation system 1 and main pipe 1, and on-off valve 2 controls the entire subsurface drip irrigation system 2 and main pipe 2. The conventional subsurface drip irrigation layout is drip irrigation system 1, and the alternate subsurface drip irrigation crosses drip irrigation system 1 and drip irrigation system 2, as shown in Figure 2 Subsurface drip irrigation system 1 is used for irrigation once, and subsurface drip irrigation system 2 is used for irrigation next time, and so on, until the cutting period, i.e., the initial flowering period of alfalfa.
[0031] 3. Irrigation schedule
[0032] Irrigation in the first year began on June 24 and ended on September 30, and in the second year began on May 8 and ended on September 20. If extreme rainfall occurred during the experiment, it was calculated according to the difference between evapotranspiration and precipitation during the experiment whether irrigation was needed, and if the precipitation exceeded the evapotranspiration, the irrigation plan was delayed for one week. Extreme rainfall occurred on July 29, August 8, August 19, August 26, and September 2 in the first year, so irrigation was delayed. The number of irrigations in the first year was 13, the irrigation amount for moderate water deficit was 260 mm, and the irrigation amount for severe water deficit was 130 mm. The number of irrigations in the second year was 19, the irrigation amount for moderate water deficit was 380 mm, and the irrigation amount for severe water deficit was 190 mm. The specific irrigation schedule is shown in Table 1.
[0033] Table 1 Irrigation schedule of alfalfa under different water deficit degrees
[0034]
[0035]
[0036] 4. Alfalfa management
[0037] The planting area is continuously planted with alfalfa for 4 years in the early stage, and on May 10 of the first year, rotary tillage, harrowing and compaction are performed, and then the residual roots of alfalfa are removed to ensure the uniformity of the planting area. On May 20 of the same year, alfalfa (MF4020) is sown by artificial strip sowing at a sowing amount of 20 kg / ha, and the sowing depth is 5 cm and the row spacing is 20 cm. After sowing, micro-sprinkling irrigation is used during the seedling stage, and the irrigation amount is 10 mm per time, and the irrigation amount during the seedling stage is 50 mm. The sowing and growth season in the first year is from May to September, and 3 harvests are obtained; the growth season in the second year is from April to September, and 4 harvests are obtained, and the cutting system of each harvest is shown in Table 2.
[0038] Table 2 Cutting system of each harvest of alfalfa
[0039]
[0040] All the field management of different irrigation modes described above are consistent. After each cutting, weeds are manually removed. When pests occur, 20% imidacloprid 1000 times liquid is used, and the application amount is 1 kg / acre.
[0041] 5. Results
[0042] Figure 3 The annual yield of alfalfa under the implementation of the present application, the yield of alfalfa under the alternating underground drip irrigation is increased by 6% and 60% respectively compared with the yield of alfalfa under the conventional underground drip irrigation under the condition of moderate water deficit, and the yield of alfalfa under the alternating underground drip irrigation is increased by 14% and 50% respectively compared with the yield of alfalfa under the conventional underground drip irrigation under the condition of severe water deficit. The annual yield of alfalfa described above is calculated according to the yield of each harvest of alfalfa, Figure 4 As shown in the table, the yield of alfalfa under different water deficit degrees is significantly improved, especially in the first harvest of the first year and all the harvests of the second year.
[0043] The alternating drip irrigation method for increasing the yield of alfalfa can alternately reduce the excessive water consumption caused by the spatial migration of water, so as to improve the yield of alfalfa in water-deficient areas.
[0044] The above description is only a preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled persons in the technical field, some improvements and replacements can be made without departing from the principles of the present application, and these improvements and replacements should also be regarded as the protection scope of the present application.
Claims
1. An irrigation method for increasing alfalfa yield under water deficit conditions, characterized in that, The method includes using a system consisting of an underground drip irrigation system 1, an underground drip irrigation system 2, a main pipeline 1, a main pipeline 2, a switch valve 1, and a switch valve 2 during irrigation.
2. The irrigation method according to claim 1, characterized in that, The underground drip irrigation system 1 and the underground drip irrigation system 2 are arranged intermittently in the irrigation area, and are independent of each other and do not affect each other.
3. The irrigation method according to claim 1 or 2, characterized in that, The method further includes alternating the use of the underground drip irrigation system 1 and the underground drip irrigation system 2 during irrigation.
4. The irrigation method according to claim 1 or 2, characterized in that, The underground drip irrigation system 1 or underground drip irrigation system 2 adopts a "one pipe for four" laying method, with one drip irrigation tape for four rows of alfalfa.
5. The irrigation method according to claim 1 or 2, characterized in that, The underground drip irrigation system 1 and the underground drip irrigation system 2 are laid at intervals of 20 to 60 cm, preferably 40 cm.
6. The irrigation method according to claim 1 or 2, characterized in that, The underground drip irrigation system 1 and the underground drip irrigation system 2 are buried at a depth of 10-30cm, preferably 20cm.
7. The irrigation method according to claim 1 or 2, characterized in that, The underground drip irrigation system 1 and underground drip irrigation system 2 are buried drip irrigation tapes with a diameter of 16mm, a dripper spacing of 10-40cm, preferably 30cm, and a flow rate of 1-5L / h, preferably 3L / h.
8. The irrigation method according to claim 1, characterized in that, The diameters of the main pipe 1 and the main pipe 2 are selected according to the size of the controlled area. The diameter of the main pipe should be 16mm larger than the diameter of the drip irrigation tape, and the diameter should be 32-72mm, preferably 32mm.
9. The irrigation method according to claim 1, characterized in that, The underground drip irrigation system is switched on and off via solenoid valves or manual valves, and pipe 1 and main pipe 2 are connected.
10. The irrigation method according to claim 1, characterized in that, The switch valve 1 controls the entire underground drip irrigation system 1 and the main pipeline 1, and the switch valve 2 controls the entire underground drip irrigation system 2 and the main pipeline 2.
11. The irrigation method according to claim 1, characterized in that, The method further includes row sowing with alfalfa row spacing of 10-30cm, preferably 20cm, a sowing rate of 10-30kg / ha, preferably 20kg / ha, and a sowing depth of 2-5cm.
12. The irrigation method according to claim 1, characterized in that, The method further includes starting water deficit irrigation at the alfalfa branching stage, calculating the irrigation amount based on the actual local crop evapotranspiration, with moderate and severe water deficits being 2 / 3 and 1 / 3 of the actual crop evapotranspiration, respectively, and the irrigation frequency being once a week.