暗管排水条件下土壤特性和作物产量的空间变异性分析

土壤水盐及作物参数空间结构的研究是改善农田管理水平的基础。该文对暗管排水条件下玉米试验田不同深度的土壤含水率、盐碱度及作物植株高度和产量的空间结构进行了计算和分析。试验结果显示，土壤含水率的自相关距离除在0.3～0.6 m土层为20 m外，其它深度均小于5 m。土壤电导率和钠吸附比的自相关距离随土壤深度的增加而增大，但随玉米的生长而减小，一般都小于40 m。玉米植株高度、干物质量和籽粒产量的自相关距离分别为20～25，10和22～42 m。玉米高度和产量与土壤含水率正相关而与土壤含盐量负相关。土壤盐分对玉

Analysis of spatial variability of soil characteristics and crop yield under subsurface drainage

Research of spatial structures of soil properties and crop characteristics is essential on improving farm management level. The spatial variability of soil water content, salinity, and sodicity at different soil depths, as well as crop height and yield in a cornfield (Zea mays L.) with subsurface drainage was calculated and analyzed. The experimental results indicated that the autocorrelation distances of soil moisture contents at various depths were smaller than 5 m except at the depth of 0.3～0.6 m, in which it was 20 m. The autocorrelation distances of electric conductivity (EC) and sodium adsorption ration (SAR) in saturated soil paste extracts increased with soil depth but decreased during corn growth period, and they usually were less than 40 m. The autocorrelation distances of corn height, dry matter weight, and grain yield were 20～25, 10, and 22～42 m, respectively. Corn height and yield were positively correlated with soil water content but negatively with soil salinity. Soil salinity affected on crop grain yield more seriously than on dry matter formation, so saline soil is more suitable to growth of forage crops.