In the heart of China’s agricultural landscape, a pressing issue has emerged: a significant mismatch between manure nutrients and crop demands. This spatial decoupling, as it’s known, leads to pollution in areas where manure is overabundant and nutrient deficits in regions where crops are most intensively grown. A recent study published in *npj Sustainable Agriculture* sheds light on this problem and offers a promising solution, with significant implications for the agriculture sector.
The study, led by Ke Xu of the SCNU Environmental Research Institute at South China Normal University, diagnosed the distribution and drivers of nitrogen (N) and phosphorus (P) nutrient mismatches across China. The findings reveal a stark regional imbalance, with surpluses in the western regions and deficits in the densely populated and grain-producing east. “The imbalance is dominated by a nitrogen gap,” Xu explains, “which is driven by a complex interplay of regional socio-economic development, cropping structure, and manure management efficiency.”
The consequences of this imbalance are far-reaching. In surplus areas, excess manure leads to environmental pollution, while in deficit regions, crops lack essential nutrients, impacting yields and quality. To address this, Xu and his team developed a sophisticated optimization model using the Non-dominated Sorting Genetic Algorithm II (NSGA-II). This model aims to minimize transport distance and application-phase greenhouse gas (GHG) emissions while respecting ecological thresholds.
The proposed solution involves strategic redistribution of manure. By redistributing 0.300 million tons of nitrogen and 0.047 million tons of phosphorus to recipient provinces, the study found that land carrying capacity saturation rates (LCCSRs) in surplus regions could be reduced to safe levels. Nationally, the average LCCSRs could decrease by 39.3% for nitrogen and 24.1% for phosphorus. Importantly, the increase in GHG emissions was controlled to within 8.5%, ensuring that the solution is both effective and environmentally friendly.
The commercial impacts of this research are substantial. For the agriculture sector, the optimization model offers a practical tool for sustainable manure management, enhancing nutrient use efficiency and reducing environmental pollution. This can lead to improved crop yields and quality, benefiting farmers and agribusinesses alike. Moreover, the study provides a quantitative basis for regional circular agriculture and ecological sustainability, aligning with China’s carbon neutrality goals.
Looking ahead, this research could shape future developments in the field by promoting a more integrated approach to nutrient management. As Xu notes, “Our study offers theoretical and practical optimization tools for sustainable manure management under China’s carbon neutrality, advancing nutrient goals and establishing quantitative bases for regional circular agriculture and ecological sustainability.”
In an era where sustainability and efficiency are paramount, this study provides a blueprint for balancing agricultural productivity with environmental stewardship. By addressing the spatial decoupling of manure and crop nutrients, the agriculture sector can move towards a more sustainable and profitable future.