膜下滴灌棉田土壤水分参数的空间变异性分析

Spatial Variability of Soil Moisture Parameter of Mulched Drip Irrigation Cotton Adopting Grid Sampling

以新疆生产建设兵团石河子国家农业科技园区的膜下滴灌棉田作为试验区,采用均匀法布点方式,测定了各个采样点0～20、20～40和40～60 cm三个不同深度土壤的含水率,利用地统计学理论分析了膜下滴灌棉田均匀布点方式下土壤含水率的空间变异规律,并利用Sufer绘制了土壤含水率的等值线图,结果表明:①膜下滴灌棉田均匀布点采样方式下,东西方向即沿膜向的半方差函数值在0～20、20～40和40～60 cm深度层的变化规律趋于一致,随着深度增加棉田的土壤含水率的空间变异强度在逐渐减小;②各方向的半方差函数值的相关性均随着深度增加棉田的土壤含水率的空间结构性更加显著;③东西方向的空间变异性随着深度的增深而减小,其他方向的空间变异性随着深度的增深而增大;东西方向即沿膜向为弱变异,其他方向20～40 cm层为强变异,0～20、40～60 cm层为中等变异。

Taking typical field in the National Agricultural and Technology zone of the Xinjiang Production and Construction Crops in Shihezi as an example.Basing on random sampling,soil samples were obtained from each point under three layers of 0～20 cm,20～40 cm,40～60 cm.The analysis of the spatial variability of soil moisture parameter was focused on using Geo-statistics and Sufer.The results show that： grid sampling in drip-irrigated cotton under mulch,semi-variogram value tends to identical in three layers of 0～20 cm,20～40 cm,40～60 cm,the deeper of sampling point,the smaller of the spatial variability;relativity of the semi-variogram value at different angles is more obvious,the deeper layer with more obvious relativity,which indicates that following the deeper layer of soil,the spatial variability is becoming obvious;the deeper of sampling point at the plastic mulch direction,the smaller of the spatial variability,the others are contrary,spatial variability at the plastic mulch direction is the weak intensity,other directions,which is the middle intensity in two layers of 0～20 cm and 0～60 cm,20～40 cm layer is the obvious intensity.