喷灌压力、喷嘴直径和喷洒历时对土壤入渗性能的影响

选取适宜的允许喷灌强度是避免喷灌条件下水土流失的重要措施之一。通过田间试验，测定了不同喷灌压力与喷嘴直径条件下土壤结皮厚度、表层土壤容重以及土壤入渗性能随喷洒历时的动态变化。试验处理包括2种质地土壤(壤质砂土和粉质黏壤土)、3个喷灌压力(103,138,172 kPa)和3个喷嘴直径(3.97,5.95,7.94 mm)。结果表明，喷灌压力越大，土壤结皮厚度和表层容重越小，土壤稳定入渗率越大。喷嘴直径越大，土壤结皮厚度和表层容重越大，土壤稳定入渗率越小。土壤结皮厚度和表层容重随着喷洒历时的增加显著增大，而土壤稳定入渗率则随之对数减小。喷洒动能强度是一个描述喷洒水滴对土壤入渗率影响的优选参数。研究结果为允许喷灌强度的确定提供科学依据。

Effects of Sprinkler Pressures, Nozzle Diameters and Spraying Duration on Soil Infiltration Property

Selecting a suitable allowable sprinkler intensity is one of the important measures to avoid soil and water erosion under sprinkler irrigation conditions.Field experiments were conducted to determine the dynamic changes of soil crust thickness,surface soil bulk density and soil infiltration property with spraying duration under different sprinkler working pressures and nozzle diameters.The experimental treatments included two texture soils (loamy sand and silty clay loam),three sprinkler working pressures (103,138,and 172 kPa) and three nozzle diameters (3.97,5.95,and 7.94 mm).The results showed that the soil crust thickness and the bulk density of surface soil decreased with the increase of sprinkler pressure,while the steady soil infiltration rate increased.The greater the nozzle diameter was,the greater the soil crust thickness and the surface soil bulk density were,while the smaller the steady soil infiltration rate was.Soil crust thickness and surface bulk density increased significantly with the increase of spraying duration,while the steady soil infiltration rate decreased logarithmically.The specific power of spraying droplets was an optimal parameter to describe the impact of spraying kinetic energy on soil infiltration rate.The results provide a scientific basis for the determination of allowable sprinkler intensity.