Author(s)

Sarah Vieira Novais^1*, Mariana Delgado Oliveira Zenero¹, Elizio Ferreira Frade Junior¹, Renato Paiva de Lima², Carlos Eduardo Pelegrino Cerri¹

¹Department of Soil Science, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo, Piracicaba, Brazil.
²Department of Environmental Sciences, Federal Institute of Mato Grosso, Barra do Garça, Brazil.

Increases in greenhouse gases (GHG) emissions, upon changes in land use and agricultural management, lead to a search for techniques that enhance carbon residence time in soil. Pyrolysis increases the recalcitrance of organic materials and enhances their activities as physical, chemical and biological soil conditioners. Emissions of CO₂, CH₄ and N₂O quantified from a sandy soil that was treated with three rates (12.5, 25 e 50 Mg·ha^-1) of either non-pyrolysed poultry manure and sugarcane straw or biochars, pyrolysed at two contrasting temperatures (350°C and 650°C). Subsequently, the flux of the three gases was converted and compared in a standard unit (CO₂eq). The added biochars, significantly reduced GHG emissions, especially CO₂, relative to the non-pyrolysed materials. The greatest differences between applied rates of poultry manure, relative sugarcane straw, both to biochar and raw material, and the positive response to the increase of pyrolysis temperture, confirm the importance of raw material choice for biochar production, with recalcitrance being an important initial characteristic. Greater emissions occurred with intermediate rate of biochars (25 Mg·ha^-1) amendment to the soil. These intermediate rates had higher microbial biomass, provided by an intermediate C/N ratio derived from the original soil and the biochar, promoting combined levels of labile C and oxygen availability, leading to an optimal environment for microbiota.

CO₂, CH₄, N₂O, Weathered Soil

Vieira Novais, S. , Oliveira Zenero, M. , Frade Junior, E. , Paiva de Lima, R. and Pelegrino Cerri, C. (2017) Mitigation of Greenhouse Gas Emissions from Tropical Soils Amended with Poultry Manure and Sugar Cane Straw Biochars. Agricultural Sciences, 8, 887-903. doi: 10.4236/as.2017.89065.