Effects of Increasing Rates of Potassium and Magnesium Fertilizers on the Nutrient Contents of Sunflower Leaf

Abstract

This research was carried out to determine the effects of potassium sulphate (50% K₂O; 0, 4, 8, 12 kg K₂O da^-1) and magnesium sulphate (16% MgO; 0, 2, 4, 6 kg MgO da^-1) fertilizer applications in a calcareous loamy soil on the contents of macro- (N, P, K, Ca, Mg, S) and micro-nutrients (Fe, Zn, Mn, Cu, B) in sunflower leaves under field conditions in Altınekin District, Konya Province, in 2009 and 2010. A factorial experiment design in randomized blocks with 4 replications of each treatment was used. After conducting soil analysis, a single base application of K and Mg fertilizers were applied during sowing. Applications of K alone in increasing doses increased the some nutrient contents in the leaves, and synergic relationships were determined between K and Fe or Mn. Similarly, applications of Mg alone also increased some nutrient contents in the leaves, and synergic relationships were determined between Mg and Mn or B. Generally, combined applications of K with Mg resulted in maximal nutrient contents in the leaves by reducing the antagonistic effect of Ca, K, and Mg cations in the soil on plant uptake of nutrients.