Mixed crop-livestock systems: what are the effects of agricultural practices on soil organic matter content and microbial activity?

Soil organic matter (SOM) content drives the physical, chemical, and biological processes taking place in soils because it affects microbial activity. In this study, we asked the following question: in agroecosystems, what are the effects of certain agricultural practices on SOM and the activity of soil microbes? Experiments carried out at six different research facilities were used to explore the impacts of potential agricultural practices used in mixed crop-livestock systems on SOM and the activity of soil microbes. The results show that the agricultural practices studied here (i.e., use of livestock effluent, incorporation of temporary grasslands, reduction in soil preparation) can increase SOM content and significantly boost the activity of certain microbial enzymes that help break down SOM. As a result, these practices reinforce the ability of soils to provide minerals that plants can exploit with a view to limiting the use of synthetic inputs in forage systems.