Manure’s Double-Edged Sword: China’s Recycling Push Risks a Climate Backlash

Chinese scientists have developed a high-resolution modelling framework that reveals a critical tension at the heart of China’s agricultural green transition. Using a dataset of over 2,100 observations, researchers created machine-learning models to simulate nitrous oxide (N₂O) emissions under different fertilization regimes. Their findings challenge the singular focus of policies like the 14th Five-Year Plan for National Agricultural Green Development, which prioritizes manure recycling rates above all else.

The study, published in Global Change Biology, shows that simply replacing chemical fertilizers with manure is not a climate panacea. Without corresponding improvements in manure-nitrogen use efficiency, the strategy could increase total national N₂O losses from 243.7 Gg in 2019 by nearly a fifth. The research emphasizes that the interaction effects between chemical nitrogen and manure nitrogen are crucial — a factor often overlooked in oversimplified emission estimates. The findings pinpoint Northcentral China as a current emission hotspot and argue that future policy must incentivize both higher recycling rates and smarter manure management.

Why it matters:
This work provides evidence-based guidance for China to refine its agricultural policies, avoiding an unintended increase in greenhouse gas emissions. For global climate modellers and agricultural policymakers, the study offers a transferable framework that underscores the need for integrated nutrient management strategies, not merely volume-based recycling targets. The stakes are high: agriculture remains the largest anthropogenic source of N₂O, a potent greenhouse gas.

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