Study on the Effect of Water, Fertilizer and Biochar Interaction on N2O Emission Reduction in Paddy Fields of Northeast China

Taking the black soil of northeastern cold land as the research object, this paper adopts the three-factor quadratic saturation D311 optimal design scheme, uses static black box-gas chromatography to analyse the irrigation season, nitrogen fertilizer and straw biochar to the impact of greenhouse gas emissions for N2O growing season in the northeast cold paddy field. This paper also studies the optimal water and fertilizer application scheme for N2O control. The results show that the effects of three factors on N2O emissions are as follows: nitrogen fertilizer > biochar > water. The irrigation and biochar have an inhibitory effect on N2O emissions, while nitrogen fertilizer has a promoting effect on N2O emissions. The performance is as follows: water + nitrogen fertilizer can promote the emission of N2O; water + biochar can inhibit the emission of N2O; nitrogen fertilizer + biochar can promote the emission of N2O. Combined with the yield, the integrated water and biochar optimization schemes, when controlling the increase of N2O growth season in paddy fields to not exceed 10% are as follows: The amount of irrigation is 4252~5531 kg/hm2; the nitrogen application rate is 103.30~117.35 kg/hm2; and the amount of biochar is 15.12~24.42 t/hm2.