滴灌条件下石膏配比对盐碱土水盐运移特征影响

Effects of gypsum proportion on water and salt transport characteristics under drip irrigation

针对西北等干旱地区土地次生盐渍化的问题,以室内实验为基础,研究了不同石膏配比对盐碱土土壤盐分运移和水分运动的影响。结果表明,不同石膏配比对滴灌盐碱土土壤水分分布具有影响,对盐碱土盐分运移影响明显。随着湿润锋水平、垂直运移距离的增加,不同石膏配比的土壤含盐量增加,在相同入渗距离内,随着石膏配比的增加,钠离子含量减小,脱钠区深度系数增大,脱钠效果明显,石膏配比为0.1的脱钠区深度系数增加比率最大。因此,施加石膏有利于滴灌淋洗土壤盐分。

In order to solve the secondary saline-alkalization problems in the northwest arid areas of China, based on the laboratory experiment, soil water movement and salt transport in saline-alkali soil under different gypsum proportions were investigated. The results showed that the gypsum proportion had a great impact on the distribution of water in soil and the salt transport of saline-alkali soil was significantly influenced by it. With the increase of the horizontal and vertical advance distances of soil wetted front, the soil salinity also increased under different gypsum proportions. In the same infiltration distance, with the increase of gypsum proportion, the sodium content decreased while the sodium desalinization zone depth coefficient increased, which showed that the desalinization effect was distinct. When the gypsum proportion was 0. 1, the increment of the sodium desalinization zone depth coefficient was greater than that of any other treatments. So the gypsum was propitious to wash soil surface salt under drip irrigation.