滴灌棉田土壤水分测点最优布设研究

Study on the placement of sensors for moisture content in soil profile for cotton under mulched drip irrigation condition

为寻求滴灌棉田土壤剖面水分测点的最优布设方案,2009年在棉花生育期内采用取土烘干法对膜下滴灌棉田不同位置、不同深度土壤质量含水率进行连续监测。利用监测数据分析了膜下滴灌棉田土壤剖面内不同观测点垂直方向上各层次土壤含水率之间的相关关系,并利用R型谱系聚类法对剖面内各观测点8个土壤层次的土壤含水率变量进行分类,筛选出适合膜下滴灌棉田墒情观测的土壤水分测点布设方案。最后利用2007年试验数据对提出的水分测点布设方案进行验证,结果表明,水平方向上距滴灌带0 cm、32.5 cm和50 cm处3个观测点,各观测点垂直方向上0~10 cm、20~30 cm、40~50 cm和60~80 cm深处4个层次12个测点的土壤含水率能较好地反映整个剖面的土壤水分信息,可作为膜下滴灌棉田土壤水分探头的布设点。

In order to find the layout scheme of moisture probes in soil profile for drip irrigation under mulch, a field experiment was conducted in the oasis region of Xinjiang during 2009. Based on the observation data of moisture content in different depths and different positions in soil profile which were monitored with oven drying method, the corre-lation of soil water content in different depths and different positions was analyzed, the data of 8 depths at different posi- tions were sorted by R type hierarchical clustering method, and the layout scheme of soil moisture probes was screened out in cotton filed with drip irrigation under mulch. The experimental verification results showed that it was reasonable that soil moisture probes were embed into 0 - 10 cm, 20 - 30 cm, 40 - 50 cm and 60-80 cm in vertical direction and 0 cm, 32.5 cm and 50 cm distance with drip line in horizontal direction.