基于Meta分析的农田秸秆输入方式对中国旱作农田土壤呼吸的影响

Effects of farmland straw input methods on soil respiration in dry farmland of China based on Meta analysis

目的研究农田秸秆输入后对中国旱作农田土壤呼吸的影响,为准确理解中国旱田农业生态系统碳排放提供重要的数据支撑和理论依据。方法基于国内外已发表的83篇研究论文,利用Meta分析技术分析农田秸秆输入后土壤呼吸改变量与土壤温度、土壤水分、土壤有机碳(Soil Organic Carbon,SOC)和土壤微生物量碳(Soil Microbial Biomass Carbon,MBC)改变量之间的内在联系。结果与结论与传统耕作秸秆不输入(CT)相比,传统耕作秸秆输入(CTS)、传统耕作秸秆粉碎输入(CTCS)、传统耕作秸秆覆盖输入(CTMS)、传统耕作秸秆粉碎覆盖输入(CTMCS)、传统耕作生物炭输入(B)、传统耕作生物炭+秸秆输入(BS)、传统耕作+覆膜(F)和传统耕作+覆膜+秸秆输入(FS)对土壤呼吸、土壤温度、土壤水分、SOC和MBC影响显著。农田土壤呼吸在CTS,CTCS,CTMS,CTMCS,BS,F和FS处理下增加了7.1%~111.4%,在B处理下减少了9.6%,平均增加了17.7%;土壤温度只在CTCS下减少了5.7%,在其他处理下的影响不显著。土壤水分在CTCS,F和FS处理下增加了9.3%~77.1%,平均增加了7.2%;SOC在CTS,CTCS,B,BS,F和FS处理下增加了12.7%~45.5%,平均增加了17.6%;MBC在CTS,CTCS,B和BS处理下增加了18.3%~71.4%,平均增加了19.1%。农田秸秆输入后,农田土壤呼吸改变量与土壤温度、土壤水分、SOC和MBC改变量密切相关,对农田土壤呼吸改变量的贡献呈现出SOC>MBC>土壤水分>土壤温度的趋势。在中国旱作农田生态系统中除了环境因素以外,底物有效性(SOC和MBC)也是调控秸秆输入后农田土壤呼吸大小的关键因素。

Purposes—To study the effects of straw input on soil respiration in dry farmland in China,and to provide important data support and theoretical basis for accurately understanding the carbon emissions of agricultural ecosystems in dry farmland in China.Methods—Based on 83 research papers published at home and abroad,the internal relationship between the change of soil respiration and the change of soil temperature,soil moisture,soil organic carbon(SOC)and soil microbial biomass carbon(MBC)after the straw input was analyzed with Meta analysis technology.Results and Conclusions—The results showed that conventional tillage with straw input(CTS),conventional tillage with straw crushing input(CTCS),conventional tillage with straw mulching input(CTMS),conventional tillage with straw crushing and mulching input(CTMCS),conventional tillage with biochar input(B),conventional tillage with biochar and straw input(BS),conventional tillage with film mulching(F),and conventional tillage with film mulching and straw input(FS)have,compared with conventional tillage without straw input(CT),significant effects on soil respiration,soil temperature,soil moisture,SOC and MBC.Soil respiration increased by 7.1%~111.4%under CTS,CTCS,CTMS,CTMCS,BS,F and FS treatments,but decreased by 9.6%under B treatment,with an average increase of 17.7%.Soil temperature decreased by 5.7%,while the impact under other treatments was not significant.Soil moisture increased by 9.3%~77.1%under CTCS,F and FS treatment,with an average increase of 7.2%.SOC increased by 12.7%~45.5%under CTS,CTCS,B,BS,F and FS treatment,with an average increase of 17.6%.MBC increased by 18.3%~71.4%under CTS,CTCS,B and BS treatment,with an average increase of 19.1%.After straws are input into farmland,the change of soil respiration was closely related to that of soil temperature,soil moisture,SOC and MBC,and further studies found that the contribution to the change of farmland soil respiration showed the trend of SOC>MBC>soil moisture>soil temperature.Therefore,in China's dry farmland ecosystem,in addition to environmental factors,substrate availability(SOC and MBC)is the key factor to regulate the size of farmland soil respiration in response to straw input.