Environmental and Management Factors Affecting Greenhouse Gas Fluxes From Soils in Mixed Crop–Livestock Systems: A Meta‐Analysis

Recent studies have suggested that diversified cropping systems integrating crop and livestock operations can enhance food production while reducing inputs and environmental impact. Nevertheless, the effect of integrated or mixed crop–livestock systems (MCLSs) on soil greenhouse gases (GHGs) emission, specifically nitrous oxide (N 2 O), methane (CH 4 ), and carbon dioxide (CO 2 ), and the moderating variables influencing them have not been comprehensively examined across diverse regions and management scenarios. Here, we conducted a meta‐analysis of 21 independent MCLS studies comparing soil GHG fluxes from croplands of MCLSs with fluxes from croplands within purely arable systems. Our results revealed that the primary moderating variables of GHGs emissions (CO 2 , N 2 O, and CH 4 ) from MCLS were, in descending order of importance: drainage class, stocking density, climate, amount of N fertilizer, fertilizer type, soil texture, crop type, tillage, livestock type, and MCLS type. However, differences in CO 2 emissions within categories of stocking density, climate, crop type, livestock type, tillage, and N fertilizer amount and type were not significantly affected by MCLS. Additionally, drainage classes, stocking density, climate, soil texture, and amount and type of nitrogen (N) fertilizers emerged as the primary contributors to both N 2 O and CH 4 emissions. Maximum emissions of N 2 O, CH 4 , and CO 2 were recorded from sand (38%), clay (33%), and sand (36%) soils, respectively. Conservation tillage (CST), sheep, cereals, and forage rotation systems were also identified as significant factors in increasing GHGs emissions. In conclusion, our meta‐analysis provides the first comprehensive assessment of the response of three major soil GHGs emissions to MCLS and demonstrates the need for further investigation into moderating variables under which MCLS can be sustainably intensified.