红壤坡地土壤水分亏缺特性分析

采用土壤水分张力计观测研究了江西红壤坡地年内土壤水分变化特征,分析对比了土壤不同层次、时间和坡位的土壤水吸力变化,以及在百喜草种植、百喜草覆盖、裸露3种处理下红壤坡地土壤水分亏缺状况。结果表明:不同土层、不同坡位、不同土地利用类型土壤水分亏缺程度不同。从土壤水分亏缺的垂直变化来看,底层>表层>中层。不同土层,其水吸力随时间变化的趋势与变化范围也不同,各土层年均土壤水吸力表现为:下层>上层>中层,同时上层土壤水吸力变化幅度大,中层、下层变化幅度较小;从不同坡段来看,上坡中坡土壤水分略微亏缺,下坡土壤水分充足。从不同土地利用措施来看,百喜草种植的区域水分亏缺度最大,百喜草覆盖的区域土壤水分亏缺度最小。

Analysis on Characteristic of Soil Water Deficit on Red Soil Slope Land

Based on the measurement with tensiometer,characteristics of soil water seasonal dynamic in sloping red soil lands in Jiangxi Province were investigated.The effects of soil depths and slope positions on changes of soil water potential were analyzed.The status of soil water deficiency under three treatments(Paspalum notatum flugge planting,mulched by Paspalum notatum flugge,bared land) was compared.The results showed that soil water deficiency status was different at different depths under different land use types.From the view of soil profile,the order of soil water deficiency was: bottom layer>surface layer>middle layer.The order of annual mean values of soil water potential was: bottom layer>surface layer>middle layer.The variation of soil water potential was higher at surface layer than other layers.The upper and middle slope had moderate soil water deficiency while foot of slope had sufficient water supply in soil.In terms of land use types,the soil water deficiency under Paspalum notatum flugge planting treatment was the highest while the treatment mulched by Paspalum notatum flugge was the lowest.