土地利用变化对土壤有机碳、全氮的影响——以右玉县牛心堡乡为例

Effects of Land Use Changes on Soil Organic Carbon and Total Nitrogen—Taking Niuxinbao Township in Youyu County as an Example

研究土地利用变化中土壤有机碳（SOC）、全氮（TN）的变化是为了正确评价其生态效应。在对右玉县牛心堡乡耕地、由耕地变更而来的苗圃地、人工林地和休耕地的土壤样品测试基础上,运用单因素方差分析方法,探讨了土地利用方式变化对SOC,TN的影响。结果显示,土地利用方式变化加大了不同深度土层间以及同一深度土层不同土地利用类型间SOC,TN含量的差异程度,增强了SOC与TN含量的线性正相关性,显著提升了土壤C/N值;利用方式变化后,剖面深度0~30 cm内SOC平均含量比耕地增加了15.10%~41.26%,其中,休耕地和林地的SOC平均含量显著高于耕地,TN平均含量为休耕地〉耕地〉苗圃地〉林地,耕地休耕或转换为林地有利于SOC的累积,研究区土地利用方式变化已经产生了正面的生态效应。

A deep understanding of the change of soil organic carbon （SOC） and total nitrogen （TN） during land use changes is significantly important for its ecological benefits evaluation. Based on the soil samples analysis on cultivated land, nursery land, plantation foresfland and abandoned land, taking Niuxinbao township in Youyu county as an example, the effects of land use changes on SOC and TN were discussed by ANOVA. The results showed that due to land use changes, the differences of SOC and TN content among soil layers and land use types in the same depth soil layer increased, the linear positive correlation between the contents of SOC and TN enhanced, and the soil C/N value significantly increased. After land use changes, the average content of SOC increased by 15.10%-41.26% in the depth of 0-30 cm. The SOC average content of plantation forestland and abandoned land were far higher than that of cultivated land. The average content of TN was in the order of abandoned land 〉 cultivated land 〉 nursery land 〉 plantation forestland. Land fallow and returning farmland to forest were beneficial to the accumulation of SOC. Land use changes already had positive effects on the ecological environment in the study area.