黄土丘陵半干旱区柠条林对土壤物理性质及有机质的影响

Effects of Caragana korshinskii Plantation on Soil Physical Properties and Organic Matter in Semi-arid Loess Hilly Region

在野外调查和室内实验分析的基础上,研究了黄土丘陵区不同林龄柠条人工林地土壤物理性质和有机质的变化情况。结果表明:随着柠条林龄的增加,柠条林可增加土壤粉粒和黏粒含量,降低土壤容重(50a柠条除外),改善毛管孔隙状况,促进土壤的正向发育,>5mm土壤水稳性团聚体含量逐渐增加,而>0.25mm水稳性团聚体和有机质均出现先减小后增大的现象;在土壤剖面上,由于表层土壤受到根系和枯落物的共同影响,柠条林对表层土壤的各项物理性质改善作用最为明显,随土层深度增加其改善作用逐渐减弱。

Based on field investigation and analysis in lab,the variation of physical properties and organic matter of soil under impacts of Caragana korshinskii plantation with different ages in loess hilly region were studied in this paper. The results showed that as age grew,Caragana korshinskii plantation could increase silt and clay proportions in soil but lower the bulk density （except 50 years old plantation）,besides,improve the soil porosity,promote positive development of the soil. In the aging process of Caragana korshinskii plantation,the content of water stable aggregate〉5 mm gradually increased; the content of water stable aggregate〉0.25 mm and organic matter declined at first,then increased. Caragana korshinskii plantation had the most obvious improving effect on physical properties of top soil layer. But deeper the soil profile was,the weaker the effect was.