耕作方式对稻田土壤有机碳组分含量及其分布的影响  

Effect of Tillage on Content of Density Fractions of Paddy Soil Organic Carbon and Its Spatial Distribution

作　　者：徐尚起[1] 崔思远[1] 陈阜[1] 肖小平[2] 张海林[1] 

机构地区：[1]中国农业大学农学与生物技术学院/农业部农作制度重点开放实验室,北京100193 [2]湖南省土壤肥料研究所,长沙410125

出　　处：《农业环境科学学报》2011年第1期127-132,共6页Journal of Agro-Environment Science

基　　金：国家"十一五"支撑计划项目(2006BAD15B01);公益性行业(农业)科研专项(200803028;200903003)

摘　　要：为深入了解耕作方式对土壤碳组分含量的影响,以南方双季稻田为研究对象,研究了翻耕秸秆不还田(CT)、翻耕(CTS)、旋耕(RTS)和免耕(NTS)4种耕作处理对土壤轻组有机碳(LF-OC)、重组有机碳(HF-OC)、土壤轻组组分(LF)和重组组分(HF)的影响。结果表明,不同耕作方式下,土壤轻组中有机碳含量介于191.21～251.54gC·kg-1,fraction之间,轻组有机碳(LF-OC)含量介于3.01～9.27gC·kg-1之间,为土壤总有机碳(TOC)的11.84%～23.31%;耕作扰动导致土壤LF-OC的损失,而秸秆投入能够增加LF-OC;NTS处理利于表层土壤有机碳的积累,但不利于亚表层土壤有机碳的积累;RTS和CTS处理有利于有机碳增加,但LF-OC分解较快;CT处理则导致土壤有机碳的流失。LF-OC与TOC变化相似,呈显著正相关关系(R2=0.84),且LF-OC对耕作措施的响应比TOC更为剧烈,可以作为指示土壤有机碳库变化的灵敏指标。The objective of this study was to understand effects of tillage on soil carbon and different fractions of it.Four tillage treatments were set up on the Double-Cropped rice field：conventional tillage without straw return（CT）,conventional tillage（CTS）,rotary tillage（RTS）and no-tillage（NTS）.The heavy fraction of soil（HF）,light fraction of soil（LF）,high fraction organic carbon（HF-OC） and light fraction organic carbon（LF-OC） were measured,and the effect of tillage on different fractions of soil organic carbon were also analyzed.Results showed that soil organic carbon concentration in the light fraction were between 191.21～251.54 gC·kg-1,fraction,and the light fraction organic carbon content（LF-OC） ranged from 3.01 gC·kg-1 to 9.27 gC·kg-1,which account for 11.84%~23.31% of total soil organic carbon（TOC）.Both of LF-OC and LF decreased with increases in soil depth.Tillage lead to the loss of LF-OC,while straw returning would increased the LF-OC.NTS was of benefit to the carbon accumulation of surface soil（0～5 cm）,but was not conducive to the carbon accumulation of subsurface soil（5～20 cm）;RTS and CTS were favorable to the increasing of organic carbon,but the LF-OC of them decomposed rapidly;CT would result in the loss of soil organic carbon.The variation trend of LF-OC and TOC were similar,showed a significant positive correlation（R2=0.84）,and the reposition of LF-OC to the farming was more intense than the TOC.LF-OC can be used as a sensitive index to directive changes in soil organic carbon pool.

关 键 词：耕作 有机碳 密度分组 双季稻田 

分 类 号：S153.6[农业科学—土壤学]