Fig. 2From: Biochar addition alleviate the negative effects of drought and salinity stress on soybean productivity and water use efficiencyShoot biomass (a, b, c), root biomass (d, e, f), total biomass (g, h, i) and root length (j, k, l) as affected by the interactive effects of drought and salinity stress as well as biochar addition. D-C = no drought stress; D-L = low drought stress; D-H = high drought stress. The bars indicate the standard error of the means (±SE). Different letters indicate significant differences according to the Fisher’s LSD testBack to article page