Biochar's Impact on Chemical and Microbial Processes Influencing Nitrogen Cycling in Agricultural Soils.

Biochar soil amendments can play a role in reducing the environmental impact of agricultural production by retaining reactive nitrogen (N), increasing carbon (C) sequestration and decreasing N₂O emissions. Biochar amendments alter N cycling in soils by changing the soil environment impacting chemical, physical and microbial processes, but a mechanistic understanding of the primary controls and N transformation processes affected is still lacking.  Overall our study explores biochar’s impact on soil N cycling by measuring changes in inorganic and organic N pools across four agricultural soils. While many biochar incubations have focused on different biochar feedstock and production processes, this study explores biochar’s impact across a gradient of soil textures, pH, and C and N content. In terms of mechanisms, the study examines whether biochar’s modification of soil N cycling is primarily controlled by chemical processes such as sorption or microbially meditated processes. The incubation examined changes in greenhouse gas fluxes, inorganic N (both in the bulk solution and sorbed to the biochar) and microbial biomass to determine how the underlying soil properties impact biochar’s effect on N transformation. Here we presents the overall project’s scope and approaches and some preliminary results on the impacts of biochar across soil types.