Effect of Biochar on CH4 and N2O Emissions from Lou Soil

Abstract

In order to investigate the effect of biochar on CH4 and N2O emissions from Lou soil, field plot experiments of winter wheat were conducted with five levels of biochar addition (0, 20, 40, 60, and 80 t·hm-2). The fluxes of CH4 and N2O, wheat production, soil organic carbon, soil water content, and temperature of each soil layer were measured. The results showed that the fluxes of CH4 and N2O changed significantly in different growth periods of winter wheat. Compared with the control, the cumulative CH4 uptake under the biochar amendment increased by 12.88%-71.61%. When the biochar addition was ≥ 40 t·hm-2, the cumulative CH4 uptake was significantly higher and the highest uptake was at the level of 40 t·hm-2. Biochar amendment had no significant effect on cumulative N2O emissions and the global warming potential (GDP). The greenhouse gas intensity (GHGI) decreased by 13.24%-22.14%. The wheat yield increased by 1.72%-32.19% after biochar addition. When the applied biochar level was ≥ 40 t·hm-2, the wheat yield increments were significantly higher. The biochar addition of 40 t·hm-2 was the optimal level for increasing the wheat yield. The soil organic carbon and water content under biochar amendment increased by 1.42-2.69 times and 7.08%-11.96%, respectively. The results suggested that Lou soil was the sink of atmospheric CH4 and the emission source of N2O during the winter wheat growth period, and the biochar level of 40 t·hm-2 was the optimal addition amount.