黑土区不同土地利用方式土壤水分动态变化特征研究

Study on Soil Moisture Characteristic of Different Land Use Types in Black Soil

在中国科学院海伦农田生态系统国家野外科学观测研究站,应用田间定位试验研究了玉米地、休闲地、苜蓿地和裸地4种不同土地利用方式下农田黑土水分动态变化特征。结果表明:土壤剖面0-190 cm水分含量随深度的增加呈先增加后减小的趋势,不同土地利用方式下农田黑土表层0-30 cm的土壤含水量差异较明显,总体表现为裸地相对较高,其次为休闲地、苜蓿地和玉米地;研究时段内土壤水分的动态变化具有明显的季节性,一般可以划分为水分相对稳定期、水分消耗期和水分补给期3个时期;根据变异系数将土壤水分的垂直变化划分为活跃层、次活跃层和相对稳定层,变异系数随土层深度的增加而减小。

Based on field fixed experiment in Hailun national field research station, dynamic change characteristic of soil moisture with different land use types were analyzed. The results showed that soil moisture （0--190 cm） presented increase-decrease with the increase of soil depth, and the difference of soil moisture in various land use types was significant in 0--30 cm soil layer, soil moisture increased in the order of corn land〈alfalfa land〈fallow land〈bare land. Soil moisture seasonal change was found in observation period, and was divided into three stages： relative stabi- lization, consumption and supplement stage. Based on variation coefficient of soil moisture, vertical change of soil moisture was divided into three layers generally： the active, the sub-active and relatively steady layer, and variation coefficient decreased with the increase of soil depth.