Fig. 7

Correlations between N surplus and GHG emissions (a, b, c), the acidification potential (d, e, f), and the eutrophication potential (g, h, i). The black solid line represents the linear correlation; green, yellow, and orange dots represent environmental impacts of rice, wheat, and maize production in Yunnan Province from 2002 to 2021, respectively. P < 0.01 indicates the significance of the regression.