Saline stress in maize plants: II - Cationic macronutrients and their relations with sodium

Abstract To evaluate the effects of soil salinity on the mineral nutrition in the maize, UFVM 100 cv., an experiment was carried out in drainage lysimeters under greenhouse conditions. An completely randomized experimental design was used, with seven treatments. The treatments consisted of irrigation with freshwater, without leaching, and the other six ones irrigated with saline water (1.2 dS m-1) with leaching fractions of 40, 30, 20, 15, 10 and 5% of the applied irrigation depth with three replications. The effects of the soil salinity upon mineral nutrition of the maize crop were evaluated, by determining the leaf content of the cationic macronutrients and their relationships with Na+ at 120 days after planting and at the phenological phase corresponding to physiological maturation. The increased soil salinity elevated the leaf sodium contents and the relationships Na+/Ca2+, Na+/Mg2+ and Na+/K+ rations, as well as reduced the contents of the calcium, magnesium and potassium macronutrients.