Fig. 3: Direct and indirect greenhouse gas (GHG) emissions in the diversified crop rotations.
a Annual mean N2O emissions; b CH4 emissions; c GWPN2O+CH4; d indirect GHG emissions; e changes in soil carbon stock in the 0–90 cm depth; f net GHG emissions. In a–c, diamond box plots show triangles spanning 25 and 75 percentiles meeting at the median. Small squares indicate means. Whisker lines extend to the minimum and maximum. In e and f, error bars in each column represent the standard deviation of whole-profile sums of three replicates. In a–c, e, and f, one-way ANOVA with two-sided and post-hoc test was conducted for statistical significance; different lowercase letters denote significant differences between the rotations at P < 0.05. The exact P values: P < 0.001 in a–c and f. In e, ** denotes significant changes in soil carbon stock in the 0–90 cm soil layer between 2016 and 2022 at P < 0.01 (P = 0.005 for SpWM, P = 0.002 for PWM and SWM). Treatment abbreviations: WM winter wheat–summer maize (control case), SpWM sweet potato→winter wheat–summer maize rotation, PWM peanut→winter wheat–summer maize rotation, SWM soybean→winter wheat–summer maize rotation, SmWM spring maize→winter wheat–summer maize rotation, RSWM ryegrass–sorghum→winter wheat–summer maize rotation. Source data are provided as a Source Data file.
