膜下滴灌条件下水分对棉花根系分布特征的影响

通过分层土柱挖掘法，研究膜下滴灌条件下不同滴灌量棉花（Gossypium hirsutum L．）根系的分布特征。结果表明：直径〉1mm的粗根只分布在40cm以上的土层；随着土层深度增加，棉花根系生物量逐渐减少；但随着滴灌量减少，土壤深层根系生物量有增加趋势。不同处理的根系生物量的分布与土层深度呈显著的负指数关系，棉花细根生物量、根长、根表面积在土壤中垂直分布都呈“单峰型”曲线变化规律；但随着滴灌量的减少，棉花根系消弱系数β呈增加趋势。

Root Distribution Characteristics of Cotton in Different Drip Irrigation Amounts Irrigation Under Mulched

The distribution characteristics of cotton roots(Gossypium hirsutum L) in different irrigation amounts were investigated by digging in this study.The result indicates that: with depth increased,root biomass gradually decreased in different irrigation amounts.But there is an increased trend in deep-seated root biomasses only with irrigation amount decreased.Underground biomass has a significant negative logarithm relation with soil depth in different irrigation amount.Root length and root surface area have the same changeable rule.In every irrigation amount treatment,with depth increased,root length and root surface area change as a single peak curve with the increase of soil depth.Root extinction coefficient of cotton in different irrigation amounts was calculated by SigmaPlot.The result indicates: with irrigation amount decreased,root extinction coefficient of cotton shows an increased trend.