[Effect of Biochar on CH₄ and N₂O Emissions from Lou Soil]

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.