黄土坡地耕作侵蚀对土壤养分影响的研究

通过地形测量、铯-137示踪、土壤性质分析及重复耕作的方法对黄土坡地耕作侵蚀对土壤养分的影响进行了研究,结果表明:全N、碱解N及有机质含量随投影坡长的变化可用抛物线描述,有效P及速效K的变化可用幂函数描述;全N、碱解N、速效K含量与耕作侵蚀的关系可用线性方程描述,有效P含量的关系可用三次多项式描述;耕作侵蚀对全N、碱解N、有效P及速效K含量的贡献率分别为16.47%、2.69%、48.85%及15.30%;由于耕作侵蚀,15年内碱解N、速效K、有机质及阳离子代换量的含量将在耕作侵蚀区呈减少趋势,在耕作沉积区呈增加趋势

Effects of Tillage Erosion on Soil Nutrients in Loess Sloping Land of China

The effects of tillage erosion on soil nutrients in Loess sloping land of China were studied with topography measurement, ¹³⁷Cs tracing, analysis of soil properties, and repeated tillage. The results show that spatial variations of total nitrogen, available nitrogen and organic matter with horizontal slope length can be described with parabola, and that spatial variations of available phosphorus and available potassium with horizontal slope length can be described with power function. Relationships between tillage erosion and total nitrogen, available nitrogen and available potassium can be described with linear equation, and the relationship between tillage erosion and available phosphorus can be described with cubic polynomial. Contributions of tillage erosion to total nitrogen, available nitrogen, available phosphorus and available potassium are 16.47%, 2.69%, 48.85% and 15.30%, respectively. With tillage erosion, the available nitrogen, available potassium, organic matter and cation exchanging capacity will decrease the tillage erosion area and increase tillage deposition area of hillslope in 15 years.