Effect of biochar on growth and ion contents of bean plant under saline condition

A pot experiment was conducted with three biochar ratios (non-biochar, 5, and 10% total pot mass) and three salinities (control, 6, and 12 dSm(-1) sodium chloride) treatments. At the flowering stage, we harvested common bean (Phaseolus vulgaris L. cv. Derakhshan) plants and measured growth characteristics and nutrient contents. As an average, salt stress decreased shoot and root dry weight, leaf area, relative water content, chlorophyll fluorescence (Fv/Fm) and leaf chlorophyll content, however, increased root length, sodium (Na) content of root and shoot, Na uptake, and translocation of bean plants, compared to control. On the other hand, the growth and ion contents of bean were affected positively by use of biochar, but Na translocation was not changed. Addition of biochar improved content of chlorophylls a, b, and total, and potassium (K), calcium (Ca), and magnesium (Mg) contents, while, diminished Na content and uptakes. Moreover, in case of measured parameters, 10% biochar was more effective compared to 5%. Overall, biochar enhanced growth of a bean under saline condition, which may have contributed to the reduction of Na uptake and enhance of K, Ca, and Mg contents.