深层坑渗灌灌水器开孔率对土壤水分入渗特性的影响研究

Study on the effect of opening pore rate of irrigator on the infiltration characteristics of soil water content under condition of deep pit irrigation

为了研究深层坑渗灌灌水器开孔率对土壤水分入渗特性的影响,在室内开展土箱机理实验,试验土壤为哈密砂土,选取了5个灌水器开孔率,分别为1.35%、2.2%、4.95%、7.5%和13.75%,设定灌水定额为12L,研究了不同灌水器开孔率的土壤水分入渗特性。结果表明:灌水器开孔率越大,相同时刻的累积入渗量、入渗速率、水平和垂直湿润锋越大,然而灌水器开孔率大于7.5%将对哈密砂土土壤水分入渗特性的影响很小;不同开孔率条件下累积入渗量和湿润锋随时间的变化规律均符合幂函数关系;在灌水定额相同的条件下,灌水器开孔率对土壤水分的分布影响不大。研究结果为深层坑渗灌技术的实际运用奠定了理论基础。

In order to explore the effects of different opening pore rates of irrigator of deep pit irrigation on infiltration characteristics of soil water content,the infiltration characteristics of soil water content for the sandy loam soil under the condition of five opening pore rates of irrigator(i.e.,1.35%,2.2%,4.95%,7.5% and 13.75%)are studied with irrigating water quota of 12L.The results are as follows:The cumulative infiltration,infiltration rate,horizontal and vertical wetting front are large with increase in opening pore rate of irrigator,but the impact of opening pore rate of irrigator on the characteristics of soil water infiltration is little with opening pore rate of more than 7.5%.The power function is used to fit the relationship between the migration distance for wetting front of soil water content and time.The spatial distribution of soil water content for different opening pore rates of irrigator are similar under condition of same irrigating water quota.These research results are of theoretical basis on practical application of deep pit irrigation.