Biochar: Potential Eco‐friendly Waste for Mitigation of the Stress Impacts of Irrigation with Brackish Water on Beans

ABSTRACT The aim of this study was to determine the potential of biochar to alleviate salt stress in beans, as well as how salinity stress affects the growth and physiological characteristics of bean plants during development. Three distinct irrigation water salinity doses (control, 2.3 dS·m −1 and 4.6 dS·m −1 NaCl concentrations) and three different doses of biochar (0%, 5% and 10% by weight of soil) were used to assess the effects. Salinity stress and the use of biochar significantly affect many attributes of bean development. Compared with the untreated control, the application of biochar increased the plant height by up to 133%, increased the stem diameter by up to 44% and increased the vegetative biomass by as much as 93%. The number of pods produced by every plant increased by 43%, the pod length increased by 32%, the pod width increased by 39%, the number of seeds per pod increased by 46% and the pod yield per plant increased by 64% when the concentration of biochar was 10%. The application of biochar under salt stress increased the chlorophyll content and relative water content, decreased electrolyte leakage and proline accumulation and decreased the total soluble sugar concentration. The present study elucidates the potential use of biochar for phytoremediation in hypersaline soil through the modification of physiological responses and pigment contents in addition to mitigating the adverse effects of salt stress on bean growth and productivity.