Fig. 4: Principal component loadings of driving factors related to nutrient surpluses.

A is for nitrogen and B is for phosphorus. NNS N nutrient surplus, PNS P nutrient surplus, NNUE N nutrient utilization efficiency, PNUE P nutrient utilization efficiency, PGCO Proportion of grain crops output, PPI Proportion of primary industry, CA Cropland area, GOVAH Gross output value of animal husbandry, GOVA Gross output value of agriculture, TLI Total livestock inventory, POP Population, GDP Gross Domestic product, PP Proportion of poultry, LI Livestock intensity.