Effect of crop residue incorporation on soil organic carbon and greenhouse gas emissions in European agricultural soils

Abstract

Abstract Soil organic matter ( SOM ) improves soil physicochemical and biological properties, and the sequestration of carbon in SOM may mitigate climate change. Soil organic carbon ( SOC ) often decreases in intensive cropping systems. Incorporation of crop residues ( CR ) may be a sustainable management practice to maintain the SOC levels and to increase soil fertility. This study quantifies the effects of CR incorporation on SOC and greenhouse gas ( GHG ) emissions ( CO 2 and N 2 O) in Europe using data from long‐term experiments. Response ratios ( RR s) for SOC and GHG emissions were calculated between CR incorporation and removal. The influence of environmental zones ( ENZ s), clay content and experiment duration on the RR s was investigated. We also studied how RR s of SOC and crop yields were correlated. A total of 475 RR s were derived from 39 publications. The SOC increased by 7% following CR incorporation. In contrast, in a subsample of cases, CO 2 emissions were six times and N 2 O emissions 12 times higher following CR incorporation. The ENZ had no significant influence on RR s. For SOC concentration, soils with a clay content >35% showed 8% higher RR s compared with soils with clay contents between 18 and 35%. As the experiment progressed, RR for SOC concentration increased. For N 2 O emissions, RR was significantly greater in experiments with a duration <5 yr compared with 11–20 yr. No significant correlations were found between RR for SOC concentration and yields, but differences between sites and study durations were detected. We suggest that a long duration of crop residue incorporation is a win‐win scenario under a continental climate. We conclude that CR incorporation is important for maintaining SOC , but its influence on GHG emissions should be taken into account as well.