Revealing long-term dynamics and spatiotemporal drivers of anthropogenic nutrients inputs in China: The effects of dietary and socioeconomic factors

Anthropogenic nutrient inputs in developing countries have substantially shaped global nutrient balance pattern for the past decades, responsible for the expanding eutrophication and pollutions. The massive alteration of socioeconomic factors and dietary habit make it difficult to identify their specific impacts on nutrient balance. This study utilized the net anthropogenic nitrogen (NANI) and phosphorus (NAPI) inputs models to calculate human induced nitrogen (N) and phosphorus (P) inputs in China from 1949 to 2022, and applied the XGBoost–SHAP algorithm to estimate the driving forces of socio–economic and dietary structure on them. Our findings revealed that both nutrient inputs peaked around 2014–2015 before declining and fertilizer application was the primary contributor (56% for N, 63% for P) from 1949 to 2022. Great variation of NANI and NAPI evolution patten was found in different regions. Eastern and southern provinces (e.g., Henan, Shanghai) had the highest inputs, while western regions (e.g., Tibet) had the lowest, correlating with economic and population density disparities. Spatial clustering highlighted the need for region–specific nutrient management strategies. Dietary shifts showed increased animal–based food consumption (6.89–fold rise) and urban–rural disparities, with developed regions exceeding recommended intake levels. Driving factors for NANI and NAPI differed by regions of different development stage. Urbanization and GDP were dominant drivers in developed areas (Type I), while population was key in less–developed regions (Type II). These findings underscore the importance of tailored policies to address nutrient pollution and dietary impacts, and provide new insights for formulating nutrient mitigation strategies.