秸秆还田对麦田土壤温室气体排放影响的Meta分析

Meta-analysis on Effects of Straw Returning on Greenhouse Gas Emissions from Wheat Fields

摘要:

为系统分析不同气侯条件、土壤性质和田间管理措施下秸秆还田对小麦农田土壤温室气体排放的影响，通过文献检索整合已发表论文中的田间试验数据，采用Meta分析方法定量分析不同生产条件下秸秆还田对小麦农田土壤温室气体排放的影响，同时对秸秆还田下各影响因子对温室气体排放的相对重要性进行评估。结果表明，与秸秆不还田相比，秸秆还田显著增加土壤N2O排放量15.50%、CO2排放量10.68%、CH4吸收量26.45%（P＜0.05）。当年降雨量大于1 000 mm时，秸秆还田下土壤N2O和CO2排放量增加最少，CH4吸收量增加最多，效应值分别为5.02%、9.88%和381.63%；当年均气温为0~10℃时秸秆还田下土壤CO2排放量增加最少，当年均气温大于15℃时秸秆还田下土壤N2O排放量增加最少、CH4吸收量增加最多。秸秆还田下土壤N2O排放效应值随土壤有机碳含量增加而减小，CH4吸收效应值随土壤有机碳含量增加而增大。秸秆还田下土壤N2O排放效应值随施氮量增加而减小，CO2排放效应值随施氮量增加先增大后减小；免耕条件下，秸秆还田显著减少土壤CO2排放量10.81%（P＜0.05），显著增加CH4吸收量91.00%（P＜0.05）；秸秆覆盖还田显著增加CH4吸收量202.04%（P＜0.05）；秸秆部分还田减少土壤N2O排放量11.33%，显著增加CH4吸收量121.64%（P＜0.05）。年降雨量、土壤全氮含量、土壤有机碳含量、氮肥施用量对秸秆还田下农田温室气体排放影响较大。研究结果可为优化秸秆还田管理实践和减少农田生态系统温室气体排放提供参考。

Abstract:

Aiming to systematically analyze the effects of straw returning on greenhouse gas emissions from wheat farmland under different climatic conditions, soil properties and field management measures, field trial data from published papers were integrated through literature retrieval and Meta-analysis method was used to quantitatively study the effect of straw returning on greenhouse gas emissions from wheat farmland under various production conditions. Simultaneously, the relative importance of various influencing factors on greenhouse gas emissions was evaluated. The results indicated that compared with no straw returning, straw returning significantly increased soil N2O emission by 15.50%, CO2 emission by 10.68%, and CH4 absorption was increased by 26.45% （P＜0.05). When the annual precipitation was higher than 1 000 mm, straw returning resulted in the smallest increase in soil N2O and CO2 emissions, and the largest increase in CH4 absorption, with effect values of 5.02%, 9.88% and 381.63%, respectively. When the annual average temperature was no more than 10℃, straw returning resulted in the smallest increase in soil CO2 emissions, and when the annual average temperature was higher than 15℃, straw returning resulted in the smallest increase in soil N2O emissions and the largest increase in CH4 absorption. Under straw returning, soil N2O emission effect values were decreased as soil organic carbon content was increased, while CH4 absorption effect values were increased with the increase of organic carbon content. Under straw returning, the N2O emission effect was decreased with the increase of nitrogen application rates, while the CO2 emission effect was firstly increased and then decreased with the increase of nitrogen application rates. Under no-tillage conditions, straw returning significantly reduced soil CO2 emissions by 10.81% （P＜0.05) and significantly increased CH4 absorption by 91.00% （P＜0.05). Straw mulching significantly increased CH4 absorption by 202.04% （P＜0.05). Partial straw returning reduced soil N2O emissions by 11.33% and significantly increased CH4 absorption by 121.64% （P＜0.05). Annual precipitation, total nitrogen, organic carbon, and nitrogen application rate had significant impacts on greenhouse gas emissions from farmland soil under straw returning. These findings can provide a reference for optimizing straw management practices and reducing greenhouse gas emissions from farmland ecosystems.