Effect of Different Levels of Salinity, Zinc, and Sulfur Inoculated with Thiobacillus on Rapeseed Growth Parameters and Some Nutrient Uptake (Brassica napus L.)

In order to evaluate the effect of zinc, sulfur inoculated with Thiobacillus, and salinity caused by sodium chloride on some growth parameters and uptake of phosphorus, potassium, and zinc by rapeseed, a greenhouse experiment was conducted in factorial randomized complete block design with three replications. Treatments consisted of soil salinity at four levels (1, 4, 7, and 10 dS m-1), sulfur inoculated with Thiobacillus at two levels (0 and 500 kg ha-1) and zinc sulfate at three levels (0, 25, and 50 mg kg-1). The results showed that salinity stress affected all studied traits and caused a significant reduction in growth parameters such as plant height, root length, shoot and root dry weight, and reduced nutrient uptake; however, salinity caused a significant increase in the roots and shoots sodium concentration. Application of sulfur along with 25 mg kg-1 zinc under salinity stress improved growth traits and increased the concentration of phosphorus, potassium, and zinc by 15.26%, 110.5%, and 376.6%, respectively, and reduced the concentration of sodium in the aerial part of the plant by 34.77% as compared to the control treatment. In general, the results showed that the use of sulfur inoculated with Thiobacillus and the optimal level of zinc sulfate fertilizer (25 mg kg-1 soil) affected soil properties as well as the direct supply of macro elements; consequently, the amount of nutrient uptake increased under salinity stress and harmful effects of salinity on plants was mitigated by reducing sodium uptake.