摘要
以晋西黄土区典型刺槐+苜蓿复合系统为研究对象,分析0～40 cm土层中土壤有机质、全N、速效P和速效K质量分数在刺槐—苜蓿复合系统(包括刺槐林地斑块、苜蓿地斑块)的分布特征及边界影响域,旨在为该地区土壤养分改善、不同土地类型养分研究和林草复合系统的经营管理提供理论依据。结果表明:1)复合系统内4项土壤养分指标质量分数波动范围较大,且不同斑块类型土壤养分指标质量分数分布特征存在一定差异性,但总体上苜蓿地土壤养分各项指标质量分数均大于刺槐林地相应养分的质量分数;2)复合系统土壤养分空间分布特征为0～20 cm土层中的4项养分指标质量分数均高于20～40 cm土层中相应养分的质量分数,但各项养分指标质量分数的层次间差异性并不一致;水平方向上,在苜蓿地斑块内,除土壤全N质量分数整体水平变化趋势不明显外,其他养分指标质量分数随着距林缘距离的增加整体呈现上升的趋势;在刺槐林地斑块内,土壤有机质、全N和速效P质量分数随着距林缘距离的增加整体呈现下降的趋势,而速效K则相反;3)主成分分析结果表明,复合系统边界土壤养分影响域是从苜蓿地3 m到刺槐林地4 m,影响域宽度为7 m。
This study was conducted in Loess Plateau of western Shaanxi Province,Northwestern China by taking Robinia pseudoacacia＋Medicago sativa model as research object.Soil nutrients including organic matters,total N,available P and available K in 0-40 cm soil layer were measured and analyzed,The distribution characteristics of these soil nutrients and their depth of edge influence were studied to provide theoretical basis for soil nutrients improvement,nutrient research of different land use types and management of silvopastoral system in this region.Results showed that： 1） The four nutrients indicators fluctuated on a large span in the silvopastoral system.The distribution characteristics of soil nutrient in different patches occurred difference to some extent.In general,the contents of soil nutrient indicators in Medicago sativa field were higher than those in Robinia pseudoacacia field.2） Distribution characteristics of soil nutrients in Robinia pseudoacacia＋Medicago sativa silvopastoral system were given as follows.The soil nutrient contents were higher in 0-20 cm soil layer than those in 20-40 cm,but the their changes were different.Horizontally,in the Medicago sativa field,apart from the content of total N without significant change,other soil nutrient indicators all increased with increasing distance from forest edge to grass area.Comparably,in the Robinia pseudoacacia field,organic matters,total N,available P decreased with increasing distance from forest edge to forest area,but available K showed an opposite trend.3） According to the Principle Component Analysis,boundary soil nutrient in the silvopastoral system showed an edge effect of 4 m in grass exterior to 3 m in forest and a width of 7 m.
出处
《中国水土保持科学》
CSCD
2011年第5期48-53,共6页
Science of Soil and Water Conservation
基金
北京林业大学科技创新计划项目“晋西黄土区果农间作系统生理生态特性及生产力研究”(HJ2010-24)
国家“十二五”科技支撑计划项目“高效可持续农林复合系统构建及调控技术研究”(2011BAD38B02)
关键词
刺槐+苜蓿复合系统
土壤养分
分布特征
边界影响域
晋西黄土区
Robinia pseudoacacia＋Medicago sativa silvopastoral system
soil nutrient
distribution characteristics
depth of edge influence
loess region of western Shanxi Province
