内蒙古河套灌区局部秋浇条件下农田水盐运动特征分析

针对河套灌区局部秋浇条件下田间水盐运动的特殊性,选取典型试验区对其进行研究。结果表明:与全面灌溉相比,灌溉区地下水位在局部灌溉后回落更为迅速,灌溉可以达到很好的洗盐保墒效果;而非灌溉区则部分承泄了灌溉区的排水,地下水位和地下水含盐量都显著升高,尽管在灌溉结束后其地下水位会随着排水过程而相应回落,但在其上涨过程中却促使盐分向上层土壤运动,从而增加土壤剖面的含盐量。分析还进一步表明,局部灌溉条件下,非灌溉区水盐运动所受影响在一定程度上取决于灌溉面积所占整个区域的比重。

Water and salt movement under partial irrigation in Hetao Irrigation District,Inner Mongolia

Field experiments were conducted in Hetao Irrigation District, Inner Mongolia, to study water and salt movement under partial irrigation. Compared with uniform irrigation, groundwater of irrigated area dropped significantly faster when partial irrigation was applied, resulting in higher salt leaching efficiency. In contrast, un-irrigated area acted as temporary discharge and buffer zone between irrigated area and drainage ditches, therefore its groundwater and salinity increased significantly during irrigation period, and salt storage in soil profiles also increased consequently. Analysis further indicates that influences of partial irrigation on water and salt movement of un-irrigated area are determined by the area ratio of irrigated land to some extent.