Abstract
Salinity is a major constraint in improving agricultural productivity due to its adverse impact on various physiological and biochemical attributes of plants, and its effect on reducing nitrogen (N) use efficiency due to ion toxicity. To understand the relationship between sodium chloride (NaCl) and increased N application rates, a pot study was performed in which the ammonical (NH4+) form of N was applied as urea to maize crops at different rates (control, 160, 186, 240, 267, 293, and 320 kg N ha−1) using two salinity levels (control and 10 dS m−1 NaCl). The results indicate that all biochemical and physiological attributes of the maize plant improved with increased concentration of N up to 293 kg ha−1, compared to those in the control treatment. Similarly, the optimal N concentration regulated the activities of antioxidant enzymes, i.e., catalase activity (CAT), peroxidase activity (POD), and superoxide dismutases (SOD), and also increased the N use efficiencies of the maize crop up to 293 kg N ha−1. Overall, our results show that the optimum level of N (293 kg ha−1) improved the salinity tolerance in the maize plant by activating stress coping physiological and biochemical mechanisms. This may have been due to the major role of N in the metabolic activity of plants and N assimilation enzymes activity such as nitrate reductase (NR) and nitrite reductase (NiR).
Highlights
Salinity is a major environmental limitation, causing extensive crop losses worldwide [1]
Under the root zone of plants, a harmful condition is created by the high concentration of soluble salts such as sodium chloride (NaCl), which contribute to the inhibition of biochemical and physiological processes in plants, reducing their growth, quality, and productivity [5]
Our current work proved that maize plants with an optimal N supply (N5) could improve various nitrogen use efficiency attributes, including Nitrogen use efficiency (NUE), Nitrogen yield efficiency (NYE), Physiological nitrogen efficiency (PNE), photosynthetic N use efficiency (PNUE), and N harvest index (NHI)
Summary
Salinity is a major environmental limitation, causing extensive crop losses worldwide [1]. The increase in salinity has reduced the average yield of field crops by more than 50%, and these losses are of great concern, especially for agricultural countries [2]. Under the root zone of plants, a harmful condition is created by the high concentration of soluble salts such as sodium chloride (NaCl), which contribute to the inhibition of biochemical and physiological processes in plants, reducing their growth, quality, and productivity [5]. Based on their ability to survive under a saline environment, two types
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
