不同稻草还田方式对稻田温室气体排放影响研究

本文以双季稻区早稻不同稻草还田方式田间试验为基础,采用静态箱法/气相色谱法测定3种稻草还田方式早稻期间的CH4、N2O排放速率。结果表明:不同稻草还田方式对稻田CH4的排放速率影响很大。免耕还田能降低CH4排放速率,翻耕还田和旋耕还田的CH4排放速率无明显差异;免耕还田的CH4排放峰值比翻耕还田和旋耕还田分别降低67.0%、54.3%,并迟7天出现;免耕还田CH4排放速率平均值比翻耕还田和旋耕还田分别降低了24.3%和27.0%;翻耕还田和旋耕还田CH4排放主要集中在早稻生长前期,而免耕还田CH4排放主要集中在中后期。旋耕还田和免耕还田的N2O排放峰值比翻耕推迟10天;免耕还田N2O排放速率平均值分别比翻耕还田和旋耕还田降低42.1%和16.7%。试验证明,免耕还田能降低稻田的CH4、N2O排放速率。

Greenhouse Air Emission under Different Pattern of Rice-straw Returned to Field in Double Rice Area

Based on different pattern of rice-straw returned to field in double rice area,emission of CH4 and N2O were tested in order to determined the influence of tillage to Greenhouse effect.The results indicated there was an obvious influence for pattern of rice-straw returned to field(RSRF) to emission of CH4.Zero-tillagewith straw returned to field(ZTSR) decreased the emission of CH4 and N2O so that the intensive Greenhouse effect was decreased.However,there was no significant difference between conventional tillage with straw returned to field(CTSR) and rollering tillage with straw returned to field(RTSR).Being late for 7 days,the climax of emission under ZTSR was lower 67% and 54.3% than CTSR and RTSR,respectively.The average emission rate under ZTSR was lower 24.3% and 27% than CTSR and RTSR,respectively.CH4 Emission under CTST and RTST mainly distributed in early growth period while ZTSR mainly distributed in midst and late growth period.Emission of N2O mainly took place prior to shining field period.The climax of N2O emission under RTSR and ZTSR was later 10 days than CTSR.The average emission rate of N2O under ZTSR was lower 42.1% and 16.7% than CTSR and RTSR respectively.Above all,the intensive Greenhouse effect under ZTSR can be significantly decreased.