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

ABSTRACT

Greenhouse 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.

KEYWORDS:

• Soil remediation
• soil degradation
• greenhouse gas
• plant growth
• vegetable production

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by the National Key Research and Development Plan of China (2016YFD0200302) .