Subsoiling reduces CO2 concentrations in soil profile of winter wheat – summer maize rotation ecosystem in the North China Plain: a strategy to achieve carbon neutrality in farmland

ABSTRACT

Reducing CO₂ emissions from agricultural soils is a key component of the overall carbon reduction strategy. The closed chamber method was used to continuously monitor CO₂ concentration in soil profiles of winter wheat-summer maize rotation fields in the North China Plain (NCP) during 2015–2017. Additionally, we evaluated the contribution of different tillage methods (Rotary tillage (RT), Subsoiling (SS), No- tillage (ZT), and conventional tillage (CT) in combination with Straw return (s) and straw removal (0)) to reducing soil CO₂ emission. The results showed that the concentration of CO₂ increased with the soil depth and peaked at the 150 cm layer. The trend of CO₂ concentration in soil profiles under different tillage treatments was CT_S > RT_S > ZT_S > SS_S, and the average concentration in maize season was higher than that in wheat season. In addition, soil moisture and temperature in the 0–10 cm soil layer were significantly correlated with soil CO₂ concentrations. Thus, our results highlight that the SSs plays a critical role in moderating soil CO₂ emissions. This process merits further study to effectively regulate soil CO₂ release and achieve carbon neutrality with less carbon emissions in farmland ecosystems.

KEYWORDS:

• Soil CO₂ concentrations
• soil profile
• tillage methods
• subsoiling
• carbon neutrality

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported in part by the National Nature Science Foundation of China (grant numbers 32172127, 31771737 and 31471453). Special thanks go to the reviewers who had provided much help to improve this paper.