不同农田模式下土壤有机碳、氮、磷及化学计量比的垂直分布特征

Vertical Distribution Characteristics of Soil Organic Carbon,Nitrogen and Phosphorus and Their Stoichiometric Ratios in Different Types of Cropland

为了探讨土地利用方式的改变是否会影响土壤养分的垂直分布,以次生林地为对照,研究了西南喀斯特山区玉米—大豆轮作地、甘蔗地、桑园和牧草地等不同农田利用模式下0~50 cm土层中土壤SOC、N、P、MBC、MBN及其化学计量指标的变化。结果表明:研究区域内土壤SOC、N和P含量的表层积聚程度显著低于土壤MBC和MBN,森林土壤养分表层积聚效果优于农田土壤;土壤SOC含量是影响土壤养分表层积聚的重要因子。

To explore whether cropland use patterns will affect the vertical distribution of soil nutrients,the changes of SOC,N,P,MBC,MBN and their stoichiometric ratios in 0-50 cm soil layers under different cropland use patterns(corn-soybean rotation,sugarcane field,mulberry field and pasture)in the southwest karst mountainous area were studied with secondary forest as the control.The results showed that within the research regions,the surface accumulation degree of SOC,N and P contents in soil was significantly lower than that of MBC and MBN in soil,and the surface accumulation of forest soil nutrients was better than that of cropland soil nutrients.Soil organic carbon content is a major factor affecting the surface accumulation of soil nutrients.