不同稻草还田模式下双季稻田周年CH_4排放特征及温室效应  

Annual CH_4 Emission and Greenhouse Effects in Double Cropping Rice Fields with Different Rice Straw Returning Methods

作　　者：彭华[1,2,3] 纪雄辉[2,3] 吴家梅[1,2,3] 朱坚[1,2,3] 黄涓[1,3] 

机构地区：[1]中南大学隆平分院,长沙410125 [2]湖南省土壤肥料研究所,长沙410125 [3]农业部长江中游平原农业环境重点实验室,长沙410125

出　　处：《农业环境科学学报》2015年第3期585-591,共7页Journal of Agro-Environment Science

基　　金：国家自然科学基金(31300413);国家科技支撑计划项目(2013BAD11B02)

摘　　要：采用静态箱-气相色谱法对南方双季稻田稻季无草翻耕冬季休闲(CK)、周年稻草焚烧还田翻耕(BST)、稻季稻草覆盖免耕冬季高桩(SNTH)、稻季稻草覆盖免耕冬季翻埋(SNTB)和稻季稻草翻耕还田冬季稻草翻埋(STB)5种稻草还田模式下双季稻田周年CH4排放进行观测,分析双季稻田周年CH4排放特征及其温室效应,旨在探索双季稻田CH4减排最佳的稻草还田方式及土壤耕作调控技术模式。结果表明:早、晚稻季CH4排放总量分别占全年CH4排放总量的43.9%和52.1%,冬闲季CH4排放比例很小,仅为4.0%;稻草还田显著增加了周年CH4排放总量(P<0.05),增加幅度为25.9%~92.8%(P<0.05),与STB处理相比,SNTH处理和SNTB处理均能显著降低CH4排放(P<0.05);不同稻草还田处理周年CH4温室效应大小顺序为:STB>BST>SNTB>SNTH>CK。可以看出,双季稻田稻季稻草覆盖免耕还田、冬季翻埋稻草还田或留桩还田能显著减缓因稻草直接还田CH4排放引起的温室效应,在南方双季稻区是一项可行的CH4周年减排的稻草还田调控技术模式。Returning rice straw directly to soil may increase CH4 emissions from rice fields. However, it is unclear how different straw returning methods influence CH4 emissions. In this work, a static chamber-gas chromatography technique was used to investigate CH4 emissions from double cropping rice(Oryza sativa L.) fields with different rice straw returning methods with or without soil tillage, namely tillage without straw returning(CK), tillage with incinerated rice straw returning(BST), no-tillage with rice straw covering in the growing season and high stakes in winter fallow( SNTH), no-tillage with rice straw covering in growing season and buried rice straw in winter fallow(SNTB),and tillage with straw returning and buried straw in winter fallow(STB). Results showed that CH4 emissions from early rice and late rice seasons accounted for 43.9% and 52.1% of the annual total emissions, respectively, while only 4.0% of CH4 emissions was from winter fallow season. Straw soil returning increased the total annual CH4 emissions by 25.9%~92.8%(P<0.05), compared with the CK. The STB treatment produced less CH4 emissions than SNTH and SNTB did. The greenhouse effects of different treatments were STB >BST >SNTB>SNTH>CK. In conclusion, the greenhouse effects would be mitigated to some extent by straw covering and no-tillage in rice growth season or stubble or straw burying in winter fallow season compared to straw direct returning to soil. Therefore, SNTH and SNTB could effectively reduce the annual CH4 emission in double cropping rice system.

关 键 词：双季稻 稻田 稻草还田 甲烷 

分 类 号：X71[环境科学与工程—环境工程]