Method for safely irrigating saline water with different mineralization degrees and reducing salt in plough layer

Abstract

The invention discloses a method for safely irrigating saline water with different mineralization degrees and reducing salt in a plough layer, and relates to the technical field of agricultural irrigation, and the method is characterized by comprising the following steps: monitoring the mineralization degree of irrigation water and soil moisture and salt dynamic states under various irrigation mode conditions; through a soil column simulation test, a saline water mineralization degree threshold value suitable for irrigation of saline-alkali cultivated lands with different soil properties and salt contents is found; performing a plot test in the field, and establishing an irrigation water-soil water-underground water salt migration model under various irrigation modes; hYDRUS-1D software is adopted for dynamic simulation and prediction of soil hydrothermal salt coupling migration under different saline water irrigation conditions. The method can be suitable for different soil texture types, crop types and underground water conditions, the salt content of the saline-alkali cultivated land can be effectively reduced, on the premise that crop growth is guaranteed, salt water resources are utilized to the maximum extent, irrigation cost is reduced, sustainable utilization of the saline-alkali cultivated land is achieved, and the method has important practical application value.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural irrigation, and more specifically to a method for safe irrigation with saline water of different mineralization degrees and for reducing salt in the plough layer. Background Art

[0002] The Yarkand River Basin has a vast area of ​​saline-alkali farmland, and traditional desalinated water irrigation is costly and difficult to implement. In this context, using desalinated water to irrigate saline-alkali farmland is not only economically costly but also difficult to implement, which is a major challenge for the Yarkand River Basin where water resources are relatively scarce. Therefore, developing a safe saltwater irrigation model that suits local conditions is of great significance to improving irrigation efficiency and reducing costs.

[0003] At present, the improvement and utilization of saline-alkali farmland mainly rely on desalinated water irrigation. Although this method can effectively reduce soil salinity, its high cost limits its application in large-scale saline-alkali farmland improvement. In addition, existing irrigation technologies often fail to take into account the impact of different soil textures, crop types and groundwater diving conditions on irrigation results, resulting in low irrigation efficiency and inaccurate salt control.

[0004] With the development of agricultural science and technology, the improvement and utilization of saline-alkali farmland has received more and more attention; research and development of irrigation technology adapted to saline water with different mineralization degrees has become an important research direction to improve the utilization rate of saline-alkali farmland, reduce irrigation costs, and increase crop yield and quality. Therefore, exploring and establishing a safe irrigation and plough layer salt reduction technology model suitable for saline water with different mineralization degrees has important theoretical and practical significance for improving the sustainable utilization of saline-alkali farmland in the Yarkand River Basin and even the world.

[0005] Therefore, the present invention aims to provide a method for safe irrigation and salt reduction of cultivated layer with saline water of different mineralization degrees. In view of the limitations and development trends of the existing technology, an irrigation water-soil water-groundwater salt migration model under various irrigation modes is established, and the HYDRUS-1D software is used to dynamically simulate and predict the coupled migration of soil water, heat and salt under different saline water irrigation conditions. This method can be applied to different soil texture types, crop types and groundwater diving conditions, and can effectively reduce the salt content of saline-alkali farmland, improve crop growth conditions, and reduce irrigation costs. It has important practical application value. Summary of the invention

[0006] The purpose of the present invention is to provide a method for safe irrigation with saline water of different mineralization and salt reduction in the cultivated layer. The present invention finds the saline water mineralization threshold suitable for irrigation of saline-alkali farmland with different soil qualities and salt contents through soil column simulation test, and simultaneously conducts plot test in the field to establish an irrigation water-soil water-groundwater salt migration model under various irrigation modes. Finally, HYDRUS-1D software is used to perform dynamic simulation and prediction of soil water-heat-salt coupled migration under different saline water irrigation conditions. The method can maximize the use of saline water resources, reduce irrigation costs, and realize sustainable utilization of saline-alkali farmland under the premise of ensuring crop growth.

[0007] The above technical purpose of the present invention is achieved through the following technical scheme: a method for safe irrigation and salt reduction of cultivated layer with salt water of different mineralization degrees, comprising the following steps:

[0008] S1. Monitor the mineralization of irrigation water and the dynamics of soil moisture and salinity under various irrigation modes, and analyze the seasonal and annual dynamic changes of salinity in different soil layers;

[0009] S2. Through soil column simulation test, find the salt water mineralization threshold suitable for irrigation of saline-alkali farmland with different soil quality and salt content;

[0010] S3. Conduct field trials, set up various irrigation modes, monitor the water-salt migration and desalination effects of saline-alkali farmland under various irrigation modes, and establish irrigation water-soil water-groundwater salt migration models under various irrigation modes;

[0011] S4. Based on the irrigation water-soil water-groundwater salt transport model, HYDRUS-1D software was used to perform dynamic simulation and prediction of soil water-heat-salt coupled transport under different saline irrigation conditions.

[0012] The present invention is further configured as follows: the multiple irrigation modes respectively include a desalinated water direct irrigation mode, a brackish water direct irrigation mode, a highly mineralized salt water freezing irrigation mode, and a salty and fresh water alternating irrigation mode.

[0013] The present invention is further configured as follows: the monitoring and analysis method in step S1 comprises the following steps:

[0014] S11. Install soil moisture and salinity monitoring equipment and collect data regularly;

[0015] S12. Collect data under different irrigation modes and analyze the dynamic changes of soil moisture and salinity.

[0016] The present invention is further configured as follows: the process of establishing the model in step S3 is: using the collected data to establish an irrigation water-soil water-groundwater salt migration model, and verifying it.

[0017] The present invention is further configured as follows: the process of finding the salt water mineralization threshold in step S2 is: determining the mineralization threshold for salt water irrigation without affecting crop growth.

[0018] The present invention is further configured as follows: the process of using HYDRUS-1D software for dynamic simulation and prediction in step S4 is: using HYDRUS-1D software to simulate the coupled migration of soil water, heat and salt under different irrigation conditions to predict long-term effects.

[0019] In summary, the present invention has the following beneficial effects:

[0020] 1. The present invention significantly reduces the irrigation cost by utilizing salt water with different mineralization degrees for irrigation instead of relying entirely on desalinated water. This is particularly important in the Yarkand River Basin where water resources are scarce and the economy is lacking.

[0021] 2. The present invention improves the utilization efficiency of saltwater resources through an irrigation mode adapted to local conditions, which helps to alleviate the water resource pressure in the Yarkand River Basin.

[0022] 3. By monitoring the dynamics of soil moisture and salt and establishing an irrigation water-soil water-groundwater salt migration model, the present invention can effectively reduce the salt content of saline-alkali farmland, improve the soil structure of saline-alkali farmland, and increase the productivity of saline-alkali farmland.

[0023] 4. The present invention helps to improve crop growth conditions and thus improve crop yield and quality by determining the threshold value for safe saline water irrigation and applying a super-threshold saline water safe utilization mode.

[0024] 5. The present invention reduces the negative impact on the environment through a scientific and reasonable irrigation mode and is an environmentally friendly agricultural irrigation technology.

[0025] 6. The present invention provides a theoretical basis for the application of salt water and desalinated water, provides a new idea for reducing the cost of salt water desalination, and provides practical guidance for actual field operations.

[0026] 7. Through the application of HYDRUS-1D software, the present invention can simulate and predict the coupled migration of soil water, heat and salt under different irrigation conditions, providing a scientific basis for the optimization of irrigation modes.

[0027] 8. The present invention takes into account different soil textures, crop types and groundwater diving conditions, has good adaptability, and can be widely used in different types of saline-alkali farmland.

[0028] 9. The present invention supports the sustainable development of agriculture in the Yarkand River Basin and even in wider areas, and helps to ensure food security and ecological balance by improving the utilization efficiency of saline-alkali farmland.

[0029] 10. The present invention provides a method of scientific and technological innovation in the field of saltwater irrigation technology, promotes the progress of agricultural science and technology, and provides a new solution for the improvement of saline-alkali farmland in similar areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic flow chart of a method for safe irrigation and salt reduction of cultivated layer with saline water of different mineralization degrees in an embodiment of the present invention;

[0031] Figure 2 It is a framework structure diagram of a method for safe irrigation and salt reduction of cultivated layer with saline water of different mineralization degrees in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following is combined with Figure 1-2 The present invention is described in further detail.

[0033] Embodiment: A method for safe irrigation and salt reduction of cultivated layer with saline water of different mineralization degrees, comprising the following process:

[0034] (1) Soil moisture and salinity monitoring: In this embodiment, representative saline-alkali farmland is selected in the Yarkand River Basin, soil moisture and salinity monitoring equipment is installed, and data is collected regularly.

[0035] (2) Irrigation mode setting: According to soil texture and crop requirements, irrigation modes such as direct irrigation with desalinated water, direct irrigation with brackish water, freezing irrigation with highly mineralized salt water (winter irrigation salt), and alternating irrigation with fresh and salt water can be set.

[0036] (3) Data collection and analysis: Collect data under different irrigation modes and analyze the dynamic changes in soil moisture and salinity.

[0037] (4) Model establishment and verification: The collected data were used to establish an irrigation water-soil water-groundwater salt transport model and verify it.

[0038] (5) Determination of the salt water mineralization threshold: The salt water mineralization threshold of salinized farmland with different salt contents and soil textures was determined through soil column simulation tests and field plot tests.

[0039] (6) Irrigation pattern optimization: Based on model results and test data, optimize irrigation patterns to improve irrigation efficiency and reduce costs.

[0040] (7) Software simulation: Use HYDRUS-1D software to simulate the coupled migration of soil water, heat and salt under different irrigation conditions and predict the long-term effects.

[0041] In this embodiment, preferably, the above-mentioned salt reduction method is used. When washing salt in winter, for loam with heavy salt content (>12g / kg), the threshold of mineralization of salt water freezing irrigation is less than 13g / L; for clay with heavy salt content (>12g / kg), the threshold of mineralization of salt water freezing irrigation is less than 8g / L; for sand with heavy salt content (>12g / kg), the threshold of mineralization of direct salt water irrigation is less than 20g / L. When irrigating (cotton) during the growth period, for loam with heavy salt content (>12g / kg), the threshold of mineralization of brackish water irrigation is less than 3g / L; for clay with heavy salt content (>12g / kg), fresh water should be used for irrigation; for sand with heavy salt content (>12g / kg), the threshold of mineralization of irrigation is less than 5g / L.

[0042] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A method for safe irrigation with saline water of different mineralization degrees and salt reduction in cultivated layer, characterized by: The following steps are involved: S1. Monitor the mineralization of irrigation water and the dynamics of soil moisture and salinity under various irrigation modes, and analyze the seasonal and annual dynamic changes of salinity in different soil layers; S2. Through soil column simulation test, find the salt water mineralization threshold suitable for irrigation of saline-alkali farmland with different soil quality and salt content; S3. Conduct field trials, set up various irrigation modes, monitor the water-salt migration and desalination effects of saline-alkali farmland under various irrigation modes, and establish irrigation water-soil water-groundwater salt migration models under various irrigation modes; S4. Based on the irrigation water-soil water-groundwater salt transport model, HYDRUS-1D software was used to perform dynamic simulation and prediction of soil water-heat-salt coupled transport under different saline irrigation conditions.

2. The method for safe irrigation and salt reduction of cultivated layer with salt water of different mineralization degrees according to claim 1 is characterized by: The multiple irrigation modes include a desalinated water direct irrigation mode, a brackish water direct irrigation mode, a highly mineralized salt water freezing irrigation mode, and a salty and fresh water alternating irrigation mode.

3. The method for safe irrigation and salt reduction of cultivated layer with salt water of different mineralization degrees according to claim 1 is characterized by: The monitoring and analysis method in step S1 comprises the following steps: S11. Install soil moisture and salinity monitoring equipment and collect data regularly; S12. Collect data under different irrigation modes and analyze the dynamic changes of soil moisture and salinity.

4. The method for safe irrigation and salt reduction of cultivated layer with salt water of different mineralization degrees according to claim 1 is characterized by: The process of model establishment in step S3 is: using the collected data to establish an irrigation water-soil water-groundwater salt migration model and verify it.

5. The method for safe irrigation and stratum salt reduction using salt water with different mineralization degrees according to claim 1 is characterized by: The process of finding the salt water mineralization threshold in step S2 is: determining the mineralization threshold for direct salt water irrigation without affecting crop growth.

6. The method for safe irrigation and salt reduction of cultivated layer with salt water of different mineralization degrees according to claim 1 is characterized by: The process of using HYDRUS-1D software for dynamic simulation and prediction in step S4 is: using HYDRUS-1D software to simulate the coupled migration of soil water, heat and salt under different irrigation conditions to predict the long-term effect.

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