坐水播种时土壤临界含水率的确定

Critical Soil Moisture for Bed-irrigating Sowing

提出了坐水播种土壤临界含水率的概念和计算思路 ,根据已有的土壤水动力学理论 ,建立了计算这个临界含水率的二维数学模型 ,应用迭代法进行了求解。针对于朝阳县试验土壤 ,计算结果显示 ,播种玉米时土壤临界含水率为 17.34 %,为田间持水率的 5 8.1%。若春播时 ,土壤含水率小于 17.34 %则需要采用坐水等措施进行抗旱播种。

Concept and determination method of critical soil moisture for bed-irrigating sowing was introduced. A mathematical model with soil water dynamics theory for computing the critical soil moisture was developed in this paper. Solves for the model were determined with iterative method. To a sample dryland soil in Chaoyang county, Liaoning province, computational result of critical soil moisture content for maize sowing is about 17.34% (gravity content), or 58.1% of field capacity. The result shows that a drought-fighting bed-irrigating sowing measure should be adopted where soil moisture content is lower than 17.34%.