Understanding the linkages between organic carbon and soil functioning in support of agroecological intensification

Summary

Agroecological intensification seeks to strengthen ecosystem services, thereby sustaining high crop yields while reducing negative environmental impact. Ecosystem services depend on physical, chemical and biological soil processes, and those are influenced by the quantity and quality of soil organic carbon (SOC). I investigated how arable farm management influences SOC content and quality, and how these two aspects relate to soil processes and functioning. Organic farming was used as a model for ecologically intensive farming. Organic farming was found to have more potential to increase the content and bioavailability of SOC than conventional farming, depending on soil properties. The intensity of farm management practices was more strongly related to overall soil functioning than farming system (i.e., organic vs. conventional). Moreover, increasing the SOC content was found to be most strongly related to soil functioning, stronger than particular management practices or the diversity of soil life. SOC quality was linked to several soil functions, but these relationships were not strong nor straight-forward. These insights contribute to the further development of farm practices that support the ecological intensification of agriculture.