Zinc Application Improves Maize Performance through Ionic Homeostasis and Ameliorating Devastating Effects of Brackish Water.

Zinc application is required for optimum crop growth especially in calcareous soils located in semiarid to arid regions. The use of poor quality brackish water in arid zone agriculture further poses threat to soil productivity. Effect of Zn application (0, 3 and 9 mg kg-1) and sodium absorption ratio of irrigation water (SARiw; distilled-water control, 8 and 16 (mmolc L-1)½) on plant growth and mineral concentration (Ca, Na, K and Zn) in shoots of two contrasting maize cultivars (hybrid, FHY-993 and synthetic variety, C-20) were evaluated in a pot study. Plant shoots showed a significant decrease (up to 31%, on average basis) due to increasing levels of SARiw and a significant increase (up to 13%, on average basis) in dry matter with the application of Zn to soil. Both cultivars varied significantly in response to Zn application and SARiw. Maximum increase in growth was observed in FHY-993 with application of Zn; while minimum decrease in plant growth due to increased level of SARiw was observed in C-20. The results indicated mitigation of sodicity effects by Zn application especially for FHY-993 with higher Zn requirement. Zinc application reduced shoot Na concentration while increased shoot Ca and K concentration; therefore, significantly increased Ca:Na and K:Na ratios in plant shoots. Conclusively, Zn application to maize improved growth by balancing K:Na and Ca:Na concentration ratios in shoots of stressed maize. However, the response may vary among cultivars depending upon their Zn requirement and Na susceptibility. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]