Work

Biochar amendment reduces paddy soil nitrogen leaching but increases net global warming potential in Ningxia irrigation, China

Year: 2017

Type: article

Abstract: The efficacy of biochar as an environmentally friendly agent for non-point source and climate change mitigation remains uncertain. Our goal was to test the impact of biochar amendment on paddy rice nitrogen (N) uptake, soil N leaching, and soil CH 4 and N 2 O fluxes in northwest China. Biochar was applied at four rates (0, 4.5, 9 and13.5 t ha −1 yr −1 ). Biochar amendment significantly increased rice N uptake, soil total N concentration and the abundance of soil ammonia-oxidizing archaea (AOA), but it significantly reduced the soil NO 3 − -N concentration and soil bulk density. Biochar significantly reduced NO 3 − -N and NH 4 + -N leaching. The C2 and C3 treatments significantly increased the soil CH 4 flux and reduced the soil N 2 O flux, leading to significantly increased net global warming potential (GWP). Soil NO 3 − -N rather than NH 4 + -N was the key integrator of the soil CH 4 and N 2 O fluxes. Our results indicate that a shift in abundance of the AOA community and increased rice N uptake are closely linked to the reduced soil NO 3 − -N concentration under biochar amendment. Furthermore, soil NO 3 − -N availability plays an important role in regulating soil inorganic N leaching and net GWP in rice paddies in northwest China.

Source: Scientific Reports

DOI: 10.1038/s41598-017-01173-w