摘要
Biochar application to cropland has been recommended as a strategy to reduce increasing at-mospheric CO2 concentrations and mitigate climate change.However,the direction and magnitude of responses of greenhouse gas(GHG)fluxes to biochar application to cropland remain unclear.Our meta-analysis of 296 observations across 61 studies for the first time quantitatively estimated the effects of biochar amendment on fluxes of three GHGsCO2,N2O,and CH4.The results showed that biochar application led to a significant change in soil GHGs emissions:in general,19%for CO2,−16%for N2O(P<0.05),but no pronounced change in CH4 emissions;in paddy,−5%for CO2,−20%for N2O,but+19%for CH4(P<0.05);in upland,−18%for N2O,+12%for CO2,and high uncertainty for CH4.The responses of soil GHG flux-es to biochar application were regulated mainly by experiment length,biochar application rate,biochar properties,providing a new perspective for more comprehensive understanding on biochar.The bio-char derived from husk was recommended to apply to cropland with an application rate of 20-30 t·ha^(−1).
基金
This study was funded by the National Natural Science Foundation of China(Grant No.31470529,31270517)
Pandeng Project for Young&Middle-aged discipline leaders of Zhejiang Province(Grant No.pd2013234)
Zhejiang Province Key Laboratory for Wood Science and Technology(Grant No.2014lygcy025).
