Meta-analysis on the Effects of Organic Fertilizer Application on Global Greenhouse Gas Emissions from Agricultural Soils
To explore the direct and indirect effects of organic fertilizer application on greenhouse gas emissions from agricultural soils,a total of 1228 groups of data from 129 published studies were selected.Meta-analysis was used to analyze the effects of organic fertilizer on global greenhouse gas emissions from agricultural soils and their influencing factors.Meanwhile,a structural equation model(SEM)was further constructed to quantify and determine the causal relationships between the factors.The results showed that,overall,compared with those under no fertilization,organic fertilizer substitution increased CO2 emissions by 70.73％(lnR:0.53,95％CI:0.45-0.62),CH4 emissions by 52.58％(lnR:0.42,95％CI:0.26-0.59),and N2O emissions by 208.14％(lnR:1.13,95％CI:1.04-1.21),respectively.Compared with those under the application of inorganic fertilizers,the substitution of organic fertilizers increased CO2 emissions by 19.24％(lnR:0.18,95％CI:0.13-0.22),CH4 emissions by 27.72％(lnR:0.24,95％CI:0.15-0.34),and N20 emissions by-3.66％(lnR:-0.04,95％CI:-0.11-0.04).Under the application of organic fertilizer,the dryland system had the greatest impact on both CO2 and N20 emissions,and the rice system had the most significant effect on CH4 emission effects.The average CO2 growth rate was highest in silty soils,and sandy soils had a greater effect on the average growth rates of N20 and CH4.The average growth rate of CO2 and N2O was extremely large under straw substitution compared to that under commercial organic fertilizer and biogas.The substitution of farmyard manure had significant CH4 emissions from soil promotion.Greenhouse gas emissions were significantly increased under the nitrogen fertilizer and organic fertilizer treatments.The SEM showed that mean annual temperature(MAT)was the most important environmental determinant of CO2 and N20 emissions,in which soil CO2 emissions were significantly positively correlated with MAT(P＜0.01)and soil N20 emissions were negatively correlated with MAT.The main environmental determinants of CH4 emissions in dryland,grassland,and rice systems were annual precipitation(MAP)and mean annual temperature(MAT),respectively,which were both significantly and positively correlated with each other(P＜0.05).This research can provide a scientific basis for optimizing fertilizer management and mitigating greenhouse gas emissions from farmland.
greenhouse gas emissionsoilorganic fertilizerMeta-analysisstructural equation modelingglobal
万方数据
维普
