Supplemental Irrigation with Brackish Water Improves Carbon Assimilation and Water Use Efficiency in Maize under Tropical Dryland Conditions

Dry spells in rainfed agriculture lead to a significant reduction crop yield or total loss. Supplemental irrigation (SI) with brackish water can reduce the negative impacts of dry on net CO2 assimilation farming semi-arid tropical regions and maintain productivity. Thus, objective this study was evaluate carbon rates, indexes for use efficiency, indicators salt stress maize plants under different scenarios, without supplemental water. The experiment followed randomized block design split-plot four replications. main plots simulated scenarios found Brazilian region (Rainy, Normal, Drought, Severe Drought), while subplots were using an electrical conductivity 4.5 dS m−1. reduced photosynthetic capacity maize, especially Drought (70% reduction) (79% reduction), due stomatal nonstomatal effects. plant stress, averted excessive accumulation salts soil sodium leaves, improved rates. also promoted increase physical productivity, reaching values 1.34, 1.91, 3.03 times higher than treatment SI respectively. represents important strategy that be employed biosaline regions, which are increasingly impacted by shortage. Future studies required other systems nonsimulated conditions, as well long-term effects types region.