Integrating nutrient balance, environmental footprints and nutrient optimization strategies for sustainable potato production system in China

Optimized fertilizer managements are crucial for enhancing global food security and represent essential strategies for reducing greenhouse gas (GHG) and reactive nitrogen (Nr) emissions. However, a systematic assessment of the distribution and reduction potential for nutrient inputs, GHG and Nr emissions within the Chinese potato production system is lacking. Here, we evaluated the nutrient balance, GHG and Nr emissions in China’s major potato-growing regions using statistical data between 2011 to 2021 and explored nutrient optimization strategies towards 2060. Adopting a cradle-to-farm gate Life Cycle Assessment (LCA) approach to quantify environmental footprints associated with agricultural materials inputs (synthetic fertilizers, manure, electricity, fuel, films, pesticides) and crop growth stages. Our results indicated that both nutrient inputs and environmental footprints per hectare increased from 2011 to 2021. GHG emissions were predominantly attributed to fertilizer production and transportation (52.9%–66.8%), and Nr emissions were primarily due to N leaching (87.0%-88.5%). An optimized fertilization strategy based on the Nutrient Expert for Potato (NE_Potato), involving a reduction of N (34.4%) and P (74.5%), and an increase of K (7.8%) inputs, reduced environmental footprints by 35.9%-51.8%. Projection indicated that by 2060, optimized fertilization strategies could reduce synthetic fertilizer usage by 67.5-85.3 × 10⁴ t, decrease GHG emissions by 2.1-5.1 Mt CO₂ -eq and lower Nr emissions by 4.0-15.6 × 10⁴ N t. This study concluded that implementing optimized fertilization through NE_Potato, integrating manure and enhanced-efficiency fertilizers practices offer promising strategies to mitigate GHG and Nr emissions in China’s potato production system.