摘要
保护性耕作对于培肥地力、保障粮食安全、缓解气候变化等具有重要意义。本研究搜集了1980～2012年8月有关中国农田保护性耕作的157个试验点的303对田间定位试验数据,采用Meta分析方法定量分析了保护性耕作下我国农田耕层土壤(旱地0～20cm,水田0～15cm)有机碳(SOC)变化特征。结果表明,与传统耕作(CT)相比,传统耕作+秸秆还田(CTS)、免耕(NT)和免耕+秸秆还田(NTS)三种保护性耕作均能显著提高SOC含量,变化速率分别为NTS(0.52 g kg-1a-1)>NT(0.35 g kg-1a-1)>CTS(0.22 g kg-1a-1);三种保护性耕作下SOC变化速率为水田>旱地,一年两熟制>一年一熟制;保护性耕作下,SOC积累与否及其幅度并不完全取决于其初始有机碳含量,短期试验(≤5a)SOC增加速率是长期试验(>5a)的1.75倍,如果仅采用短期试验结果可能高估保护性耕作的固碳潜力。
Conservation tillage of farmlands is very important to soil building, guarantee of food security and mitigation of global warming. A total of 303 sets of field experiment data was collected from 157 long-term （1980--2012） conservation tillage experiment sites for meta-analysis to characterize quantitatively tranchangestion of SOC （ soil organic carbon） in the topsoil （0 - 15cm for paddy and 0 - 20cm for upland） of farmlands under conservation tillage. Results show that the practices of conventional tillage plus straw incorporation （CTS）, no tillage （NT）, and no tillage plus straw incorporation （NTS） significantly increased SOC content in the topsoil with a relative change rate （RC） being 0.22, 0.35, and 0.52 g kg^-1a^-1 , respectively, as compared with the practice of conventional tillage （CT）. The effect was more significant in paddy fields than in uplands and in farmlands under the double cropping system than in those under the single cropping system. It seems, however, that SOC accumulation and its amplitude is not fully related to the initial content of organic carbon in the soil. The SOC increase rate in short-term field experiments （≤5a） is about 1.75 times as high as that in long-term ones （ 〉 5a）. It is, therefore, possible to overestimate SOC sequestrating potential of the conservation tillage practices just based on short-term field experiments.
出处
《土壤学报》
CAS
CSCD
北大核心
2013年第3期433-440,共8页
Acta Pedologica Sinica
基金
中国科学院战略性先导科技专项-应对气候变化的碳收支认证及相关问题(XDA05050509)
中国科学院知识创新工程重要方向项目(KZCX2-EW-QN404)资助
关键词
保护性耕作
农田土壤
长期试验
有机碳变化
META分析
Conservation tillage
Cropland soil
Meta-analysis
Long-term field experiments
Dynamics of soil organic carbon
作者简介
田康（1986-），男，河南商丘人，硕士研究生，主要从事资源环境遥感及土壤有机碳动态模拟研究。E-mail：tiank@issas．ac．cn
通讯作者，E-mail：yczhao@issas．ac．cn
