无压地下灌溉新技术试验

对局部控水灌溉(无压地下灌溉)技术从理论上进行了分析，并给出了其土壤水分运动方程。在大田试验的基础上，研究分析了无压灌溉不同孔径孔口出水规律和根区局部湿润状况。试验结果表明：无压孔口出水规律与孔口孔径、地温和土壤含水量等因素有关；出水孔口孔径和初时土壤含水量对湿润锋推进速度影响较大，孔径和初时土壤含水量越大，湿润锋推进速越快；适宜的出水孔径沿管道长度方向出水均匀，5～35cm深度的土壤含水量变化无明显差异，能够满足作物需水和生理需水要求。

Experimental Research on New Technique of Non-Pressure Underground Irrigation

Theoretical analysis of local-control irrigation, i.e., non-pressure underground irrigation, is conducted, and soil water movement equation is presented. On the basis of field experiment, discharge from orifices of different diameters of non-pressure irrigation and root zone local moisture status are researched. The experiment results indicate that discharge of non-pressure orifice is related to hole diameter, soil temperature, and soil water content etc; the hole diameter and initial soil water content have great effect on advancing speed of wetting front. The bigger the hole diameter and initial soil water content, the rapider the advancing speed of wetting front. If suitable diameter orifices distribute along pipe length, the water flow is uniform. The soil water content at depth of 5-35 cm has no obvious change, and can satisfy crop water requirement and physiological demand.