渭北旱塬深层土壤水分特征对水分生产效率的影响

采用田间试验和观测方法研究了渭北旱塬东部旱作区的农田土壤水分特征和水分生产效率,结果表明,该区在麦田夏闲蓄水期(7-9月)降水量在212.7mm以下时,1～1.2m深处存在一相对干土层,使小麦生育后期对深层土壤水分利用产生一定影响,并使旱地农田水分生效率降低.研究还看出,旱地农田水分生产效率具有明显地随播前土壤储水量增加而提高的趋势,说明渭北旱塬使东部的土壤水库在旱农条件下作物供水调节中的不可代替作用.

The Effect of Depth Layer Soil Moisture Behaviors in Farmlands on Its Productive Efficiency in Weibai Dryland

The field experiments and observations were made to study soil moisture behaviors and its productive efficiency in farmlands showed that when rainfall was below 212.7mm in the water storage period of summer fallow (July to September) in this region,there existed a dry soil layer in the depth of 1-1.2 meters,which has an important impact upon the utilization of soil moisture in deep layer by winter wheat in its late developing stage,as such it were decreased that soil moisture productive efficiency.It can also be seen from the studies that soil moisture productive efficiency has an apparent tendency to rise as soil moisture storage increases before sowing.This indicates that the soil moisture reservoir has an important role in regulating water supplies to crop growth in the case of dryland farming.