Study On Crop Growth And Migigration Mechanism Water And Salt Under Intercropping Of Cotton And Mung Bean Under Mulched Drip Irrigation In Dryland

In the Xinjiang area, the water resources are extremely scarce, and perennial drip under the film leads to the harm of the secondary salinization of the arable land. The soil physical and chemical properties are deteriorated, the yield per unit area is decreased, the crop yield is reduced and the water use efficiency is reduced. In this paper, the characteristics of soil water and salt transport, the law of water consumption of crops and the mechanism of cotton growth response under intercropping were studied by pot experiment and field experiment under the condition of intercropping plants and economic crops in dryland. The main findings arc as follows:(1) The effects of root crosses on soil water and salt migration and cotton growth under different root treatment conditions were studied by pot experiment. The results showed that salt content of the soil profile under intercropping alfalfa is significantly reduced, desalination effect is better, water use cfficiency, cotton production increased. Under the condition of intercropping, the cotton growth was better under the condition of plastic cloth and gauze barrier, and the water consumption of the crop was decreased and the water use efficiency was improved, but the desalination effect was improved relatively poor.(2) The effetcts of different halophytes on soil water and salt transport mechanism and cotton growh were studied. The results showed that intercropping alfalfa and Suaede could significantly increase the water content of 0-40cm soil layer and the water consumption during the growth period,and re*duce the membrane and the membrane of soil moisture deep leakage. Intercropping Suaeda can significantly reduoce the salt content of 0-60cm soil layer. The root weight density of cotton can be increased to 40 cm deptlh, while the root weight of intercropped sophora can only reach 30cm depth. Compared with cotton monocropping, the root weight of 0-20cm soil layer was significantly larger in intergranular and membrane treatments, but the results were opposite in 20-40 cm soil layer.According to three years of intercropping experiment, intercropping Suacda and alfalfa can promote cotton growth, increase cotton production and improve watcr use efficiency.(3) Effects of different nitrogen rates on soil water and salt migration and cotton growth were studied under intercropping mung bean in cotton field condition. The results showed that the effect of nitrogen application on soil water distribution and crop water consumption was not significant.With the increase of nitrogen application rate, soil salinity and total nitrogen content were mainly accumulated in 20-40cm soil layer, organic carbon mainly accumulated in 0-30cm soil layer.Nitrogen loss was caused by excessive nitrogen application. When the nitrogen application rate was 390 kg/hm2, the growth requirement of cotton and mung bean could be better provided, and the crop growth and yield were increased, the efficiency of water use efficiency and nitrogen efficiency can be improved. Logistic growth model could simulate the growth rate of cotton and mung bean. When the nitrogen application rate was 390 kg/hm2, which was beneficial to the growth and development of cotton and mung bean, the growth rate of cotton biomass and the growth rate of mung bean were the highest.