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通过野外试验和室内分析相结合的方法,研究了民勤绿洲农田不同矿化度(0.8g.L-1、2.0g.L-1和5.0g.L-1)地下水灌溉对土壤环境的影响。结果表明:随着灌溉水矿化度的增加,生长季水分消耗量逐渐降低,土壤总孔隙度和土壤有机质含量逐渐下降,而土壤有效水含量和土壤电导率则逐渐增加。当灌溉水矿化度为0.8g.L-1时,收获后土壤中上层(0～60cm)电导率比播种前明显降低,而底层(60～90cm)电导率略有增加,即淡水灌溉的淋溶作用明显;当灌溉水矿化度为2.0g.L-1时,生长季中的灌水依然对土壤盐分有淋溶作用,但明显弱于淡水的淋溶效果,收获后土壤盐分有明显的表聚现象;当灌溉水矿化度为5.0g.L-1时,收获后在0～60cm深度电导率明显增加,在60～90cm深度没有明显变化。
Through the combination of field experiment and laboratory analysis, the effects of groundwater irrigation with different degrees of mineralization (0.8g.L-1, 2.0g.L-1 and 5.0g.L-1) on soil environment in Minqin Oasis farmland were studied. The results showed that with the increase of salinity of irrigation water, the water consumption of growing season decreased gradually, the total soil porosity and soil organic matter content decreased gradually, while the effective soil water content and soil conductivity increased gradually. When the irrigation water salinity was 0.8gL-1, the conductivity of the upper middle layer (0 ~ 60cm) of the soil after harvest was significantly lower than that before sowing, while the conductivity of the bottom layer (60 ~ 90cm) increased slightly, When the salinity of irrigation water is 2.0gL-1, the irrigation in the growing season still leaches to the soil salinity, but is obviously weaker than the leaching effect of the fresh water. After salting, the salinity of the soil is obviously aggregated When the salinity of irrigation water was 5.0gL-1, the electric conductivity increased obviously at the depth of 0-60cm after harvesting and no obvious change at the depth of 60-90cm.