Biochar-based nitrogen fertilizers: Greenhouse gas emissions, use efficiency, and maize yield in tropical soils.

The sustainable development of agriculture depends on increasing N use efficiency (NUE) and consequently reducing N losses from different sources, such as NH volatilization, NO leaching, and NO emissions. While the chemical and physical properties of biochar (BC) in fertilizers have been evaluated to increase NUE, a lack of information exists regarding the effects of BC amendments in tropical soils. We performed a one-year field experiment with tropical soil to evaluate the effects of BC-based N fertilizers (BN) on maize yield and on greenhouse gas (GHG) emissions.

Carbon stability and mitigation of fertilizer induced NO emissions in soil amended with biochar.

Biochar is a promising tool for an efficient and low environmental impact agriculture since can offer both soil carbon (C) sequestration and mitigation of nitrous oxide (NO) emissions. The extent of biochar C stability after soil amendment and efficiency in reducing NO emissions from an external nitrogen (N) source were accessed through laboratory incubations. A clay loam soil was amended with chicken manure (CM), sewage sludge (SS), eucalyptus sawdust (ES) and filter cake (FC) feedstocks and corresponding slow-pyrolysis (400°C) biochars at 5gCkg soil in combination with two N fertilizer rates (0 and 140mgNkg soil).