Abstract:In order to explore the water saving and efficient alkali-saline land pattern, the underground pipe drainage experiment was designed under the condition of drip irrigation to seek the effects of different buried spacings in the width of 15m, 20m and 25m on salt distribution in soil profile and the desalination and leaching. The results showed that soil salinity in 0~70cm soil layer was decreased significantly during the drip irrigation, and compared with CK the average salinity of soils was decreased by more than 10g/kg. Different spacing widths of 15m, 20m and 25m below 100cm soil layer indicated different maximum soil desalination rates, which were 86.47%, 84.79% and 81.35%, respectively, and the total desalination rate of soil was between 51.82% and 60.43%. The smaller the spacing of the buried pipe was, the larger the drainage flow in the drainage and drainage salinity and conductivity were, and thus the cost would be slightly higher. However, compared with 20m and 25m, the actual investment was increase by 8430 yuan/hm2 and 12570 yuan/hm2 in the spacing of 15m and the overall soil desalination rate was increased by 1%. When 15m spacing drainage pipes in the horizontal distances of 0m, 5m and 7.5m, the maximum soil desalting rate was 86.47%, 85.15% and 84.01%, respectively, and drainage flow, salinity and conductivity during drainage were 2m3/h, 189.15g/L and 35.9mS/cm, respectively. Besides, soil salinity leaching curve fitting effect was better than 20m and 25m spacing area, and overall level of soil layer below 70cm was fallen to below 10g/kg and crop growth conditions were greatly improved, which was suitable as a parameter for the layout of the underground pipe drainage pipe of Xinjiang saline soil. These results revealed that the drip evolution mode had great importance for the underground pipe drainage salinity, laied the foundation for the following long-term research, ultimately achieved improvement goals, and met the conditions for the growth of the crops.
