Localized nutrient management practices enhance the environmental-economic sustainability in potato production of China

Potatoes, as the fourth most important staple crop in China, play a crucial role in ensuring national food security. However, potato production is heavily reliant on inputs such as fertilizers and pesticides, leading to significant environmental challenges that compromise the sustainability of this production. A systematic evaluation of the current state of potato production sustainability in China and its potential for improvement is an urgent scientific issue that needs to be addressed. This study employs emergy sustainability index (ESI), energy return on investment (EROI), energy efficiency cost (EEC), and energy exchange ratio (EnER) methods to assess the environmental and economic aspects of potato production at the county level in China. Results indicate that, in 2015, the average ESI, EROI, EEC, and EnER for potato production in China were 1.37 (0.1-5.4), 2.21 (0.18-7.44), 0.06 (0.01-0.48) $/MJ, and 13.52 (2.68-112.40) MJ/$, respectively, with considerable spatial heterogeneity at the county level. Regions with higher sustainability in potato production are primarily concentrated in the northwest, which is also China's main potato-growing area. The random forest analysis identified yield, phosphorus, and nitrogen fertilizers as key factors influencing the sustainability of potato production. Regionally differentiated fertilizer management strategies led to a 43% and 35% increase in ESI and EROI, respectively, while EEC and EnER decreased by 50% and 47%. This study systematically explores the relationship between the environmental and economic dimensions of potato production from an energy perspective and proposes optimized management strategies for synergistic environmental-economic development. It provides methodological support and scientific guidance for promoting sustainable potato production and offers insights for global potato sustainability systems.