Fig. 1
Leaf photosynthetic rate (a, b), stomatal conductance (c, d), intercellular CO2 concentration (e, f), transpiration rate (g, h) and WUE-leaf (i, j) as affected by the interactive effects of drought × salinity stress and biochar × salinity stress. 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 test