The effect of biochar on the salinity reduction in mung bean plant

Abstract Salinity stress is considered as a serious threat to the growth of plants and crop yield in many parts of the world. It reduces the plant growth and crop production. The aim of research was investigation of biochar effect on reducing of salinity in mung bean plant. The experiment was performed in a randomized complete block design with two replications and three treatments of saline, non-saline and saline + biochar. A silty soil was used for the plant substrate while calcium chloride and sodium chloride salts were employed in order to create the salinity levels in it. The results of analysis of variance associated with the studied traits showed that the simple effects of salinity and plant organs as well as the interaction of salinity×plant organs on the calcium, magnesium, chlorine, sodium, potassium, pH and electrical conductivity (EC) levels are significant at a level of 1%. Also, the results of comparing the mean interaction of salinity×organ indicated that the highest calcium content in most cases is associated with the shoots. The biochar consumption has been found to reduce the calcium absorption at high salinity in leaves and roots and increase it in the stem and pod. Increasing the calcium chloride and sodium chloride salinities in plant organs, the concentration of potassium decreased compared to calcium and with increasing salinity levels, the concentration of all mentioned elements increased in most treatments. The results further showed that biochar leads to an increased pH level in the plant organs. Moreover, the EC value was found to be improved by applying biochar. In general, biochar increased salinity, but in most cases this increase was less than the salinity alone. According to the results, effect of organ, salinity and organ× salinity on all characteristics was significant. From the above results, it can be inferred that although high salinity reduces the growth of mung bean plant, this plant is resistant to low salinity levels. It has been found that the salinity resistance mechanism of this plant is the salt tolerance through the accumulation of ions in its organs. Therefore, it can be used in the improvement of saline soils, for the optimal use of soil resources and saline waters. Also, in order to prepare biochar, the type of plant and the conversion temperature of the plant to biochar should be considered.