坡耕地退耕还草对土壤活性有机碳的影响  

Effects of Returning Farmland to Grassland on Soil Active Organic Carbon in Sloping Lands

作　　者：黄江 朱丽琴[2] 申思佳 黄荣珍[2] Huang Jiang;Zhu Liqin;Shen Sijia;Huang Rongzhen(Water Resources Planning & Designing Institute of Nanchang Municipality,Jiangxi Province 330009, China;Jiangxi Key Laboratory for Degraded Ecosystems Restoration & Watershed Eco-hydrology,Nanchang Institute of Technology, Nanchang Municipality 330099,China)

机构地区：[1]江西省南昌市水利规划设计院,江西南昌330009 [2]南昌工程学院江西省退化生态系统修复与流域生态水文重点实验室,江西南昌330099

出　　处：《亚热带水土保持》2018年第4期31-34,64,共5页Subtropical Soil and Water Conservation

基　　金：国家自然科学基金项目(31160179);江西省水利厅科技项目(KT201239)

摘　　要：研究坡耕地退耕还草后的土壤有机碳及活性有机碳变化有利于了解其碳固定机制。本文采用野外调查和室内分析相结合的方法,以坡耕地为对照,2种还草整治方式(象草地和芒草地)为研究对象,探讨坡耕地还草后土壤总有机碳(TOC)、活性有机碳组分及其比例的变化。结果表明:土壤(0～60 cm)总有机碳、易氧化有机碳(ROC)、微生物量碳(MBC)含量平均值均以象草地最高,芒草地次之,坡耕地最低;而水溶性有机碳(DOC)含量平均值以坡耕地略高,但其在土壤剖面中的下降幅度最大(66. 08%)。土壤总有机碳和活性有机碳组分含量均以表层最高,说明表层土壤有机碳聚集能力更强。在不同活性有机碳组分比例中,坡耕地和芒草地以ROC/TOC最高,象草地以DOC/TOC最高,但两种还草整治方式和对照均以MBC/TOC最低(1. 06%～4. 27%)。在不同还草方式中,土壤活性有机碳组分比例以象草地最高,表明象草地更有利于活性有机碳的积累。Study on the changes of soil organic carbon(SOC) and active organic carbon(ROC) after returning the sloping farmland to grassland is helpful to understand the carbon fixation mechanism.By using the field investigation and indoor analysis,it was studied the changes of the components and proportions of total organic carbon(TOC),active organic carbon in three treatments(slope farmland,PennisetumpurpureumSchumland and Imperatacylindrica(L.)Beauv.land).The results showed that the average contents of total organic carbon(TOC),oxidizable organic carbon(ROC) and microbial biomass carbon(MBC) in soil(0～60 cm) were the highest in PennisetumpurpureumSchum land,followed by Imperatacylindrica(L.) Beauv.land and the lowest in slope farmland,while the average content of water-soluble organic carbon(DOC) was slightly higher in slope farmland,but its decline in soil profile was the largest(66.08%).The content of total organic carbon(TOC) and active organic carbon(ROC) in the surface soil was the highest,indicating that the accumulation ability of organic carbon in the surface soil was stronger.ROC/TOC was the highest in sloping farmland and Imperatacylindrica(L.) Beauv.land,while DOC/TOC was the highest in PennisetumpurpureumSchum land,but MBC/TOC was the lowest(1.06% ～ 4.27%) in three treatements.Among the different ways of returning grass,the proportion of soil active organic carbon components was the highest in PennisetumpurpureumSchum land,which indicated that PennisetumpurpureumSchum land was more conducive to the accumulation of active organic carbon.

关 键 词：退耕还草 活性有机碳 坡耕地 

分 类 号：S151.9[农业科学—土壤学]