松嫩平原西部不同土地利用方式盐渍化效应研究

在2003年6月~10月选择农田、草地和碱斑地作为典型的土地利用方式,对0~120 cm土层水盐时空动态进行了对比分析,结果发现:农田和草地土壤剖面含水量都有“上升—下降—上升”的趋势,但是在8月中旬之前农田含水量高于草地,而碱斑地含水量的变化呈“U”型。三种土地利用方式土壤剖面含盐量的变化趋势与含水量相反;土壤剖面6月7日含盐量最大,10月17日最小;农田和碱斑地土壤剖面各层含盐量在8月8日开始上升,而草地在7月7日已开始上升;从垂直剖面看,农田各个时刻土壤含盐量都随剖面深度的增加而上升,碱斑地则随着剖面深度的增加而下降,草地在各个时刻土壤剖面含盐量均呈先上升后下降型,在土壤剖面有峰存在。采样期内,草地有良好的蓄水作用,而农田土壤剖面含盐量下降幅度最大,水分、盐分在土壤剖面运移剧烈。

The Effect of Different Land-use Types on the Salination in the Western Songnen Plain

Based on analyzing the dynamic changes of water content and salt content of the 0-120cm soil profile in different land-use types in the western Songnen plain from June to October in 2003,results are as follows: the changes of water content in cropland and grassland have the same tendency — "up-down-up",but water content in cropland is more than that of grass land before the middle August.The changes of salt content in three land-use types are contrary to water content,and salt contents in 0-120cm soil profile on the 7th June are the highest,and those on the 17th October are the lowest.Salt contents of the different layers in cropland increase with the soil depth increasing,and those in alkaline spot are contrary.Grassland can keep water very well,and the decreasing extent of salt content in cropland is the most significant among three land-use types.