Fig. 4: The spatial matching degree and optimization potential of livestock production and cropland carrying capacity at OPSR.

a Current livestock production amount. b Cropland carrying capacity. c County-level livestock production surplus. d Provincial-level livestock production surplus. e Livestock transfer between and within province. f GHGs reduction potential of replacing units of synthetic N with manure N, and the maximum transport distances they support. GHGs represent the combined greenhouse effect from methane (CH4) and nitrous oxide (N2O). The error bars represent the standard deviation. The base map is applied from GADM data (https://gadm.org/).