Shiraz University Iran Agricultural Research 1013-9885 39 1 2020 03 01 Maize response to water, salinity and nitrogen levels: soil and plant ions accumulation واکنش ذرت به سطوح آب، شوری و نیتروژن: تجمع یون ها در خاک و گیاه 1 12 5657 10.22099/iar.2018.26257.1251 EN Abolfazl Azizian Department of Water Engineering, College of Agriculture, Shiraz University, Shiraz, I. R. Iran Department of Water Science and Engineering, Ardakan University, Ardakan, I. R. Iran Ali Reza Sepaskhah Department of Water Engineering, College of Agriculture, Shiraz Drought Research Center, College of Agriculture, Shiraz University, Shiraz, I. R. Iran University, Shiraz, I. R. Iran Journal Article 2017 08 15 In the present study, some nutritional imbalances, specific ion toxicity and yield-ion concentration relationships in maize under water, nitrogen (N) and salinity stresses were assessed. Effect of different levels of irrigation water (I1=1.0ET_c+0.25ET_c as leaching, I2 =0.75I1 and I3 =0.5I1) as main plot, salinity of irrigation water (S1=0.6, S2= 2.0 and S3=4.0 dS m^-1) as sub-plot and N fertilizer rates (N1=0, N2=150 and N3=300 kg N ha^-1) as sub-sub-plot on maize (cv SC 704) were investigated in a split-split-plot design with three replications during 2009 and 2010. Results showed that salts accumulated in soil were 28.4% higher in I2 compared with other irrigation treatments. Soil nitrate concentration was statistically higher under I3 and S1 treatments (83% and 10%, respectively) compared with other irrigation and salinity levels. There was no K⁺ deficiency caused by salinity; however, salinity resulted in statistically lower K⁺/Na⁺ compared with no saline conditions. Plants took up 25% higher N in I2 compared with other irrigation levels. Furthermore, N uptake by plants decreased by an average of 18% under salinity condition indicating that higher N application rate above the required level under saline water application put the environment at the risk of groundwater N contamination. Results of this study confirmed the fact that Na⁺ accumulation in soil was more detrimental than Cl^- accumulation for maize irrigated with saline water. Besides, according to threshold values for soil ions, the optimum levels of irrigation and N fertilizer for maize might be lower under saline water application. Furthermore, based on the grain yield reduction coefficient, maize required a higher level of K⁺ and K⁺/Na⁺ under deficit saline water irrigation for avoiding yield losses. https://iar.shirazu.ac.ir/article_5657_328474794c3672e9a6cd3822fb7f19b8.pdf