黄土丘陵区小流域植被恢复的土壤养分效应研究

Effects of Vegetation Restoration on Soil Nutrient in a Small Catchment in Hilly Loess Area

研究了安家坡小流域荒草地、山杏林地、农地、油松林地、灌木林地、弃耕地等地类的土壤养分特征。结果表明,植被系统具有较强的养分表层富集功能;不同植被恢复类型对土壤养分含量有明显的影响,主要表现在不同土层土壤有机质、速效磷、速效钾、硝态氮和铵态氮含量在不同植被类型间存在显著的差异性;人工灌木植被对土壤的培肥作用高于乔木植被;农地弃耕(撂荒)有一定的土壤培肥作用;对水土流失极为严重的黄土丘陵沟壑区来说,在退耕还林还草时应优先考虑恢复灌木和草本等先锋植被;在土壤质量改善到一定程度时,再进行乔木的间植;农地弃耕是一种节省人力物力而其生态环境效应又很好的双赢途径。

This paper selects the Anjiapo small catchment to study the characteristic of soil nutrient under different vegetation-land types including wasteland, almondland, cropland, pineland, shrubland and abandoned land. The results are as below: the plant communities had obvious effect on the soil nutrient by vegetation accumulation on the top of the soil with various effects of different plant, significant differences among six land use types were found on soil properties including soil organic matter, available P, available K, nitrate N and ammonia N in the 0~20 cm and 20~40 cm soil layers, the artificial shrub had a better soil fertility than that of the artificial arbor, abandonment of cropland can improve soil fertility to some degree, during the developing of Chinese 'Grain for Green Project', it is better to replace cultivated land with shrubs and grassesand plant some arbor when the soil condition is adapt to it, and the abandonment of cultivated land is a win-win way to improve the soil conditions in the hilly and severe soil and water erosion area in the Loess Plateau of China.