不同立地类型根灌、滴灌水分扩散规律

Study on Soil Moisture Diffusion Regularity in Different Site Types of Root Irrigation and Drip Irrigation

为掌握根灌、滴灌在不同立地类型土壤中的水分扩散规律,通过不同灌水梯度试验,采用挖剖面和直观观测法,研究了根灌和滴灌在不同立地类型土壤水分的垂直和水平扩散规律。结果表明:风沙土中根灌、滴灌水分垂直扩散明显小于水平扩散,且灌水时间与扩散速率均呈负相关对数关系。沙质壤土中根灌水分垂直扩散明显小于水平扩散,滴灌则垂直扩散速率大于水平扩散,两者差异不明显;灌水时间与扩散速率呈负相关对数关系。灰棕漠土中根灌初期水分垂直扩散和水平扩散相同,随时间增大,水平扩散速率大于垂直扩散;滴灌则垂直扩散速率大于水平扩散,但两者差异不明显;灌水时间与扩散速率也呈负相关对数关系。总体来看,根灌在不同立地类型土壤中的水分无论垂直扩散速率还是水平扩散速率都表现为:沙质壤土>风沙土>灰棕漠土;滴灌则无论水平扩散速率还是垂直扩散速率都表现为:灰棕漠土>风沙土>沙质壤土,两者扩散规律明显不同。

In order to grasp the soil moisture diffusion regularity in different site types of root irrigation and drip irrigation. Some experiments with different gradients are conducted. The methods of digging profile and intuitive observation are used to study the vertical and horizontal diffusion regularity of soil moisture of root irrigation and drip irrigation in different site types. The results shows that： The soil moisture verti- cal diffusion of the root irrigation and drip irrigation in aeolian sandy soil is significantly less than the horizontal diffusion, the irrigation time has a negative correlation logarithmic relationship with the rate of diffusion. The soil moisture vertical diffusion of root irrigation in sandy loam soil is significantly less than the horizontal diffusion. The soil moisture vertical diffusion rate of drip irrigation is greater than the horizontal dif- fusion, but the difference is not obvious. The irrigation time has a negative correlation logarithmic relationship with the diffusion rate of the root irrigation and drip irrigation. The vertical diffusion and horizontal diffusion of the early root irrigation in gray-brown desert soil is the same level, but with time increases, the horizontal diffusion rate is greater than the vertical diffusion. The vertical diffusion rate of the drip irriga- tion is greater than the horizontal diffusion, but the difference is not obvious. Irrigation time also has a negative correlation logarithmic rela- tionship with the diffusion rate. Overall, whether for the vertical or horizontal diffusion rates, the order of the regularity in different soil site types of the root irrigation from large to small is as follows： sandy loam soil, aeolian sandy soil, gray-brown desert soil. The order of regularity in different soil site types of the drip irrigation from large to small is as follows ： gray-brown desert soil, aeolian sandy soil, sandy loam soil. The diffusion regularity of two irrigation modes is not the same.