枣棉间作生态系统内根系和棉花产量分布及土壤养分时空变化

为提高枣棉间作系统内肥料管理水平,在棉花不同物候期,测定系统内土壤养分的空间差异性.结果表明:土壤有机质质量分数随棉花生育进程基本呈增加的趋势,且枣树西侧的土壤有机质质量分数高于东侧,并且0＜H(土层深度)≤20 cm土层有机质质量分数明显高于20 cm＜H≤40 cm土层;土壤中速效N、P和K的质量分数表现出明显的时空分布差异性.随着棉花生育进程,土壤中速效N、P、K的质量分数均呈下降趋势.在水平分布上,随距枣树距离的增加,土壤中速效N、P质量分数均表现出先下降再上升的变化规律,距离树体130 cm左右的土壤速效N、P质量分数最低,而速效K质量分数则相对较为平稳.在垂直分布上,随着土层深度的增加,土壤速效P质量分数呈明显降低现象,而速效N、K质量分数变化较小.

Distribution of Root and Cotton Yield and Temporal-Spatial Variation in Soil Nutrients in Jujube-Cotton Intercropping Ecosystem

The spatial variation in soil nutrients was studied in different phenological stages of cotton in order to improve fertilizer management in Jujube-cotton Intercropping Ecosystem(JIE).Result showed that the content of soil organic matter increased with the growing process of cotton.Moreover,the organic matter content in the soil to the west of the jujube trees was higher than that to the east,and the organic matter content in 0-20cm soil layer was higher than that in 20-40cm soil layer.Temporal and spatial heterogeneity of contents of available N,P,and K in soil was observed in JIE.Contents of available N,P,and K decreased with the growing process of cotton.In horizontal distribution,the contents of soil available N,P,and K first decreased and then increased with increasing distance from the jujube trees,and the contents of available N and P in the soil located at 130cm away from the jujube trees were lowest,while the available K content was relatively stable.In vertical distribution,soil available P content decreased with increasing soil depth,while the contents of available N and K changed little.