Interactive Effects of Potassium Sulfate and Soil Salinity on Mineral Nutrition (K, Ca, Mg) and Chlorophyll Content of Triticum Durum L. At The H’madna Station (Relizane, Algeria)

Abstract

Soil salinity is a major limiting factor in agricultural production, particularly affecting wheat. In this context, this study aims to evaluate the interactive effects of salinity and potassium fertilization (K₂SO₄) on mineral nutrition (K, Ca, Mg) and chlorophyll content in wheat. The experiment was conducted at three salinity levels (S1: unsalted; S2: slightly salted; and S3: salted) and four potassium rates (0, 150, 300, and 450 kg ha⁻¹). Les résultats montrent que la salinité entraîne une augmentation significative des teneurs en calcium (8,99 meq 100 g⁻¹ de sol ± 1,29) et en magnésium (2,02 meq 100 g⁻¹ de sol ± 0,53) dans le sol, tandis que la fertilisation potassique influence principalement la teneur en potassium assimilable (0,33 meq 100 g⁻¹ sol ± 0,20), avec des valeurs maximales observées à partir de la dose de 300 kg ha⁻¹. Au niveau foliaire, l’augmentation des apports en K₂SO₄ améliore significativement la teneur en potassium, atteignant des valeurs proches de l’optimum à partir de 300 kg ha⁻¹. In contrast, a gradual decrease in calcium (1,31% DM ± 0,32) and magnesium (0,56% DM ± 0,07) content is observed as potassium rates increase, reflecting ionic antagonism. Furthermore, salinity reduces potassium uptake and promotes the accumulation of magnesium in plant tissues. The results regarding physiological parameters indicate that salinity significantly reduces the chlorophyll a (40,27 µg/mg ± 4,42) and b (13,18 µg/mg ± 2,40) content, reflecting a decrease in photosynthetic activity. However, the application of K₂SO₄ improves these parameters, with optimal values observed at a rate of 300 kg ha⁻¹. Principal component analysis confirms that salinity is the dominant factor influencing the variables studied, while potassium fertilization partially mitigates its negative effects. An intermediate dose of 300 kg ha⁻¹ appears to be optimal for improving the nutritional balance and wheat’s tolerance to salt stress.