滴灌条件下黄棕壤土水分运动规律研究

Experimental Study on Yellow Brown Soil Water Movement Under Drip Irrigation

试验研究了不同滴速、初始含水率和容重条件下,黄棕壤土水分运动规律,并分别分析了0-5 cm、5-10cm1、0-15 cm水平和垂直方向土层含水率的相关性和变异系数。结果表明：滴速、初始含水率和容重均对水分运动有明显影响;水分水平和垂直扩散距离与入渗时间之间呈多项式关系,且R2在0.9以上;滴灌量相同滴速为3.0 L/h在滴灌过程中出现大面积积水。土壤垂直方向0-5 cm与5-10 cm含水率之间的相关性为0.883,而5-10 cm与10-15 cm的相关性则只有0.467;水平方向上5-10 cm含水率不仅变异系数高而且与相邻的0-5 cm、10-15 cm的相关性均较低,分别是0.366和0.472。因此对于黄棕壤土合理的滴速应选择在2.0-2.5 L/h范围内,土壤水分传感器埋设在距离滴头水平方向5 cm、垂直方向10 cm处比较合理。

A series of experiments about the effect of drip velocity,soil bulk density and initial moisture content on yellow brown soil water movement were carried out in laboratory,and the correlation and variation coefficient of horizontal and vertical soil moisture content in 0~5 cm,5~10 cm,10~15 cm soil layer were analyzed.The result showed that drop velocity,soil bulk density and initial soil water content had significantly effect on the soil water movement,a polynomial function relationship existed between horizontal and vertical water diffusion distance and infiltration time,and the R2 was above 0.9.Under the 3.0 L/h drip rate,surface water logging occurred for the same amount of irrigation.The correlation coefficient of vertical soil moisture was 0.883 between 0~5 cm and 5~10 cm soil layer,while it is only 0.467 between 5~10 cm and 10~15 cm.In the horizontal direction,the soil moisture in 5~10 cm layer had not only high variation coefficient but also low correlation with neighboring 0~5 cm and 10~15 cm layer,it was 0.366 and 0.472,respectively.It could be concluded that the reasonable drip velocity was in the range of 2.0~2.5 L/h,and the reasonable buried location for soil moisture sensors was in the horizontal direction from the emitter 5 cm,and 10 cm from vertical direction.