粉壤土条件下影响地下滴灌灌水器流量的因素分析

Analysis on influence factors of subsurface drip irrigation emitter discharge under silt loam soil condition

分别选取灌水器工作压力、土壤容重和土壤初始含水率为因素,采取混合水平均匀设计安排试验,对各因素实测数据进行相关、回归和通径分析,利用通径系数直接评价和比较各试验因素对地下滴灌灌水器流量的影响程度。结果表明:工作压力对灌水器流量的直接通径系数最大,土壤初始含水率和土壤容重通过工作压力对灌水器流量的间接通径系数次之,其它直接或间接通径系数很小,剩余通径系数较小。这说明试验所选的三个因素可反映地下滴灌灌水器水力要素之间的关系,其中地下滴灌中工作压力是决定灌水器流量的主要因素,土壤初始含水率和土壤容重通过工作压力对灌水器流量的作用不可忽略。

The experiment scheme was arranged based on uniform design with mix levels of three factors which are respectively work pressure of emitter, soil bulk density and initial soil water content. The experiment data of three factors was made on correlation analysis, regression analysis and path analysis. Influence degree of these factors on emitter discharge under subsurface drip irrigation （SDI） could be directly estimated and compared through path coefficients. Analysis results show that the direct path coefficient of work pressure to SDI emitter discharge is the most. The indirect path coefficients of initial soil water content and soil bulk density to SDI emitter discharge are secondary. But the other direct or indirect path coefficients are very small, and residue path coefficient is also small. Therefore the relationship of hydraulic characteristics of SDI emitter might be reflected by these three experiment factors. Work pressure is the decisive factor to SDI emitter discharge, and the influences of initial soil water content and soil bulk density on SDI emitter discharge through work pressure can not be ignored. The results have important theoretical and practical application values to SDI hydraulic calculation and engineering design.