Soil functions are affected by transition from conventional to organic mulch-based cropping system

Soil ecosystem services depend on soil properties and their interactions, which are mostly influenced by soil use and management. The main objective of the present study was to evaluate, through a multidisciplinary approach, the effect of different cropping systems on food provisioning, soil chemical features, size and structure of soil microbial community, soil invertebrate biodiversity and habitat provision (trophic interactions). The systems were: conventional integrated (INT); traditional organic with cover crops and conventional tillage (ORG); and organic coupled with conservation agriculture (cover crop mulching and no-tillage, ORG+). During 2016, we conducted soil and field samplings and collected data relative to the crop yield, C and N content in the agroecosystem, chemical and microbial soil properties and soil invertebrate abundance and trophic interactions. The INT system showed the highest crop yield (similar to ORG and three-fold higher than ORG+). Nevertheless, the INT system showed the greatest amount of N lost with drainage water (six-fold higher than the other systems), the lowest soil total PLFA abundance (around two-fold lower than ORG and ORG+ in the Ap1 horizon of soil). Additionally, INT system was characterized by the lowest invertebrate biodiversity (e.g., two-fold and tenfold lower than ORG and ORG+ respectively for ground-dwelling predator abundance). By contrast, the ORG+ system had the lowest crop yield, but it showed the highest soil total organic C concentration and microbial biomass in the Ap1 horizon, supported higher invertebrate biodiversity and a slightly wider prey-spectrum for ground beetle predators. The ORG system had an intermediate behaviour between INT and ORG+. The results of this study demonstrate that, despite the reduction of crop yield, the conversion from INT to ORG or ORG+ possibly enhances important soil functions like nutrient cycling and storage, biodiversity and habitat provisioning. However, management optimization for improving crop yield would be required to make ORG+ a viable system.