Effect of Different Levels of Water Salinity and Biochar on Wheat Yield under Greenhouse Conditions

Salinity has a negetive effect on soil physical properties and plant production. One way to compensate the negetive effect of salinity is to use the proper amendement. Biochar is an amendment, which could decrease the negative impact of salt stress on crop growth and production. A pot-experiment was conducted in greenhouse to investigate the effect of four levels of biochar (0, 25, 50 and 75 t ha-1) and four saline irrigations (0.5, 5, 7 and 9 dS m-1, 50% NaCl and 50% CaCl2 solution) on growth and yield of wheat. The experiment was performed based on completely randomized design with four saline irrigations.Results showed that in each salinity level, increasing biochar level significantly (p 5%) reduced the dry weight of straw and grain yield. At the salinity levels of 5 dS m-1, increasing biochar level to 25 ton ha-1 declined dry weight of straw and grain yield by 22 and 12.6 percent as compared to control (no biochar application), respectively. Increasing the amount of salinity in each biochar level also reduced the dry weight of wheat straw and grain yield.Increasing salinity up to 5 dS m-1 in each biochar level increased water use efficiency,while increasing salinity over 5 dS m-1 reduced the water use effciency. Further, increasing biochar to 25 t ha-1 in each level of salinity also enhanced water use efficiency, while, it was reduced by incresed biochar level. It can be concluded that salinity had a negetive effect on wheat yield performance. Unexpectedly, application of biochar declined crop yield, as the produced biochar had a saturated electrical conductivity of 1 dSm-1, which increased the salinity in the soil by applying more biochar.