Biochar amendment in reductive soil disinfestation process improved remediation effect and reduced N2O emission in a nitrate-riched degraded soil

Abstract

ABSTRACTGreenhouse cultivation with high nitrogen inputs is extensively used in the vegetable production in China, leading to severe soil degradation. To effectively improve the quality of degraded soils, reductive soil disinfestation (RSD) has been adopted as a reliable remediation method but high N2O emission would occur in nitrate-riched soils during RSD treatment. This study aimed to apply biochar amendment to reduce N2O emission during the RSD remediation of degraded vegetable soils. The remediation effect and N2O emission were investigated during the RSD process followed by tomato cultivation in pot culture experiment. Results showed that RSD treatments with and without biochar amendment both significantly increased soil pH from 4.0 to 6.1 and decreased NO3− content in degraded soil from 180 to less than 20 mg kg−1. These RSD treatments also promoted the plant growth and vegetable production in the following cultivation. Biochar amendment decreased N2O emission during the RSD treatment stage with a reduction of cumulative emission of 39%. The inhibitive effect of biochar on N2O emission was potentially realized through the increase of soil pH. Biochar amendment may be an effective means to mitigate N2O emission in the RSD application with promoting effects for vegetable growth.