黄土塬区深剖面土壤水分垂直分布特征及其时间稳定性

发布时间：2018-04-13 17:08

本文选题：土地利用方式 + 土壤水分　；参考：《应用生态学报》2017年02期

【摘要】：研究土地利用方式对深剖面土壤水分时空动态的影响,对于了解区域水循环在变化环境下的表现特征具有重要意义.本研究基于长期定位监测数据,对2012年9月至2015年12月黄土塬区4种土地利用方式0~15 m剖面土壤水分状况进行分析.结果表明:苜蓿草地(7年)、休闲地、高产农田和低产农田平均土壤含水量分别为15.1%、22.0%、19.6%和21.1%(0~15 m、年度平均值);干湿交替层季节性失水和蓄水分别出现在3—6月和7—10月,其深度范围分别为0~2、0~4.6、0~3和0~4.2 m.深层土壤水分具有较好的时间稳定性,其垂直分布受土地利用方式的影响.观测年份内苜蓿产量和耗水量均呈逐年增加趋势,造成深层土壤的干燥化程度加大,2~10 m土层形成稳定土壤干层,阻断了降水补给地下水的途径.对于其他3种土地利用方式下的土壤水分平衡,冬小麦生长季农田与休闲地均表现为负平衡;玉米生长季高产农田表现为负平衡,而低产农田与休闲地表现为正平衡;在作物休闲期,农田与休闲地均表现为正平衡.通过施肥处理所形成的高产农田的作物水分利用效率是低产农田的3倍以上.
[Abstract]:It is of great significance to study the effect of land use patterns on the spatiotemporal dynamics of soil water in deep profile and to understand the characteristics of the regional water cycle in the changing environment.Based on the long-term monitoring data, the soil moisture status of four types of land use patterns in 0 ~ 15 m profile was analyzed from September 2012 to December 2015 in Loess Plateau.The results showed that the average soil water content in alfalfa grassland (7 years, leisure land, high yield farmland and low yield farmland) was 15.122.010% and 21.1g / 15m, respectively, and seasonal water loss and water storage in dry and wet alternate layers appeared in March and June and July and October, respectively.The range of depth is 0 ~ 2 ~ 2 ~ 0 ~ 4. 6 ~ 0 ~ 0 ~ (3) and 0 ~ 4 ~ 4 ~ (2) m ~ (-1) respectively.Deep soil moisture has good time stability and its vertical distribution is affected by land use pattern.The yield and water consumption of alfalfa increased year by year during the observed year, which caused the dryness degree of deep soil to increase and form a stable soil dry layer in 10 m soil layer, which blocked the way of recharge of groundwater by precipitation.For the other three land use patterns, the soil water balance was negative in winter wheat growing season and leisure land, and in high yield field in maize growing season, but positive in low yield farmland and leisure land.In the crop leisure period, both farmland and leisure land are in positive balance.The crop water use efficiency of high yield farmland formed by fertilization treatment was more than 3 times of that of low yield farmland.
【作者单位】：中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室;中国科学院生态环境研究中心城市与区域生态国家重点实验室;西北农林科技大学水土保持研究所;平顶山学院;
【基金】：国家自然科学基金项目(41571036,41401015)资助~~
【分类号】：S152.7

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