Response of N2O emissions to different pH soils with biochar amendment

Abstract

Biochar application has the potential for mitigating N2O emissions from agriculture soils and has been suggested as a management practice to ameliorate soil fertility and increase crop productivity. Nevertheless, the influence of biochar addition on N2O emissions in different pH soils compared at same time is not reported well, which result in poorly understand of the mechanisms as regard to biochar application on soil N2O mitigation. A 40-day incubation experiment was carried out to investigate the impact of biochar on N2O emissions from different natural pH soils in the present study. Four treatments (control, nitrogen fertilizer application (N), biochar amendment, N plus biochar amendment) were set up in soils separately with three different natural pH levels (acidic vegetable soil, neutral rice soil and alkaline soil). Our results showed that the addition of biochar significantly decreased N2O emissions by 20.8% and 47.6% in acidic vegetable soil for both N and no N addition treatments, respectively. For neutral and alkaline soils, the reduction of N2O emissions by biochar amendment was only significantly for N addition treatments in alkaline soil. Soil pH and NO3−-N concentrations were significantly affected by biochar amendment (soil pH increased by 1.43–1.56, 0.57–0.70 and 0.29–0.37 units for acidic vegetable soil, neutral rice soil and alkaline soil, respectively). Overall, biochar amendment could be used as an effective management practice for mitigating N2O emissions from acidic and alkaline soils.