Smart Net-Zero

Science of The Total Environment | June 1, 2023
Straw return (SR) is a climate-smart agricultural practice recommended for enhancing soil organic carbon (SOC). To assess its effectiveness, researchers from China Agricultural University conducted a global analysis using 327 observations from 115 sites.
Their findings reveal that SR increased SOC by an average of 3.68 Mg C ha−1, with a carbon efficiency of 20.51%. Interestingly, less than 30% of the SOC increase was directly attributed to straw carbon input. The magnitude of SOC changes from SR increased with higher straw carbon input and longer experiment duration, while carbon efficiency decreased.
No-tillage and crop rotation practices were found to enhance the SOC increase through SR, especially in acidic and organic-rich soils. Machine learning analysis identified the amount of straw carbon input as the most critical factor, while local agricultural practices and environmental conditions determined regional variations.
These insights support tailored, region-specific SR policies for maximizing SOC increment while considering environmental impacts. By optimizing agricultural practices, farmers can accumulate more carbon and promote sustainable agriculture.

Graphical abstract