黄土丘陵区坡耕地土地退化研究

Land Degradation of Slope Fields in Hilly and Gully Areas of Loess Plateau

采用宏观调查和微观实验相结合,测试分析和定位观测相结合的方法,对黄土丘陵区坡耕地主要由水土流失造成的土地退化进行了研究。结果显示,黄土丘陵区坡耕地的水土流失不仅造成表层耕作土壤变薄和地表径流损失,还造成表土养分流失、土壤物理性能变差、土壤水分入渗能力下降。土地退化的最终结果是土地生产力的下降,干旱年份水土流失造成不同坡度坡耕地不同农作物的粮食减产幅度达21.9%～80.0%。

With the methods of combining macroinvestigation with microexperimentation, and test analysis with site observation, land degradation caused by soil and water loss on slope fields is studied in hilly and gully areas of the loess plateau. The results show that soil and water loss on slope fields not only brings about surface runoff loss and topsoil fertility decline, but also causes the soil nutrient loss, soil physical property damage and weakened soil infiltration capacity. The direct result of soil degradation is the reduction of land productivity. The impacts of soil and water loss in different slope fields under different crops are productivity losses of between 21. 9% and 80. 0%.