摘要
[目的]探究我国南方稻田不同秸秆还田方式下表土固碳潜力的大小。[方法]基于南方地区40个稻田长期试验点102组表土有机碳数据,利用Meta分析法研究了翻耕秸秆还田(CTS)、免耕秸秆还田(NTS)和旋耕秸秆还田(RTS)下稻田表土有机碳含量的相对年变化量、固碳持续时间及固碳周期内的固碳量。[结果]CTS、NTS和RTS均能显著提高南方稻田表土有机碳含量,其表土有机碳含量相对年变化量(RM)分别为0.42、0.37和0.64 g·kg-1·a-1,三者中,RTS为最大,约为NTS的1.7倍,CTS的1.5倍。秸秆还田下两熟制和三熟制稻田RM均值分别为0.40和0.61 g·kg-1·a-1,同一秸秆还田方式下,三熟制稻田RM显著高于两熟制,其中,NTS处理下两者差距最大,达2.0倍,CTS和RTS的差距稍小,但也分别达到了1.37和1.39倍。随着时间的延长,稻田表土有机碳积累速率逐渐降低,CTS、NTS和RTS的表土固碳持续时间分别为27、44和30年,以NTS最长;整个固碳周期内所能增加的有机碳量分别为15.8%、23.3%和27.3%,其中RTS增加最多。[结论]从农田土壤固碳角度考虑,在我国南方地区稻田旋耕秸秆还田较其他两种还田方式更为适宜。
[ Objectives] The paper aims to explore the topsoil carbon sequestration potential size under different straw return modes in paddy fields in South China. [ Methods] Based on the soil organic carbon data of 102 topsoil samples taken from dO paddy field experi- ment sites in South China,we conducted a Meta-analysis to study the relative annual change of topsoil organic carbon content （RM）, carbon sequestration duration and accumulation enhancement rates of soil organic carbon over the whole soil organic carbon sequestra- tion period in paddy fields in South China under three straw return modes, conventional tillage with straw return （CTS）, no tillage with straw return （NTS） and rotary tillage with straw return （RTS）. [ Results ] CTS, NTS and RTS could significantly increase the topsoil organic carbon content in paddy fields in South China,and the RM under CTS, NTS and RTS were 0.42,0.37 and 0.64 g·kg^-1·a^-l, respectively. The highest RM among the three straw return modes was the RTS treatment,which was about 1.7 times as large as that of the NTS treatment and 1.5 times as much as that of the CTS treatment. The average RM in double cropping system and triple cropping system under straw return treatments were 0.40 and 0.61 g· kg^-1· a^-1 , respectively, which means straw return could increase the soil organic carbon content no matter what kind of cropping system was adopted. In condition of the same straw return mode, the RM in triple cropping system was significantly higher than that in double cropping system, and the gap of RM between triple cropping system and double cropping system under NTS treatment was the highest of 2 times. While under CTS and RTS treatments,the gaps were 1.37 and 1.39 times which were slightly smaller than those under NTS treatment. The topsoil organic carbon accumulation rate decreased gradually with increasing time. The soil organic carbon sequestration duration of CTS, NTS and RTS were about 27,44 and 30 years, respectively,and the NTS treatment was the longest among them. Accumulation enhancement rates of soil organic carbon for CTS, NTS and RTS over the whole soil organic carbon-sequestration period were about 15.8%,23.3% and 27.3%,respectively,and RTS treatment was the largest among them. [ Conclusions ] From the perspective of soil carbon sequestration in cropland, straw return with rotary tillage was more appropriate than the other two straw return modes in paddy fields in South China.
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2015年第3期351-359,共9页
Journal of Nanjing Agricultural University
基金
国家科技支撑计划项目(2012BAD14B12)
南京农业大学中央高校基本科研业务费专项资金(SKCX2014001)
关键词
秸秆还田
土壤有机碳
土壤固碳
南方稻田
straw return
soil organic carbon
carbon sequestration
paddy fields in South China
