After continuous three cropping seasons,the contents of labile organic carbon components,organic carbon mineralization and the humus characteristic were determined in paddy soils under four different tillage patters (CT:conventional tillage,SCT:straw + conventional tillage; NT:no-tillage; SNT:straw + no-tillage),respectively.In 0 ～ 5 cm soil layer,no-tillage practices(NT,SNT) and rice straw management practices (SNT,SCT) could increase the labile organic carbon content,total organic carbon and humus content,raising △log K and the E4 / E6 value of humic acid.Besides,the rice straw management practices (SNT、SCT) also improved the daily amount and the total amount of organic carbon mineralization.SNT had the most obviously positive effect on them in 0 ～ 5 cm soil layer.In 5 ～ 20 cm soil layer,conventional tillage (CT,SCT) increased the contents of the highly labile organic carbon fraction,the lowly labile organic carbon fraction and total amount of organic carbon mineralization.Meanwhile,it also improved the concentrations of humus,humic acid,fulvic acid and humification degree,and raised the HA/FA ratio.SCT had the most obviously positive effect on them in 5 ～ 20 cm soil layer.It was supposed that SNT could promote humification and carbon sequestration in surface soil,while SCT had a similar function in 5 ～ 20 cm soil layer,which would decelerate the greenhouse effect induced by the increasing carbon emissions from paddy soil.
NETL
NSTL
维普
万方数据
