The effect of application of potassium, magnesium and sulphur on wheat and barley grain yield and protein content

The objective of our experiment was to study the effect of mineral fertilizers, richmainly in the K, Mg and S content, and compare their effect on grain yield and protein contentof winter wheat and winter barley with fertilizer treatments without these elements. The analyzedfertilizer treatments were 1) Control, 2) mineral nitrogen treatment (N), 3) mineral nitrogen withphosphorus (NP), 4) NP with potassium, magnesium, and sulphur (NP+KMgS), and 5) NP withmagnesium, sulphur and minor part of manganese (4%) and zinc (1%) (NP+MgSMnZn). Theexperiment was established in Lukavec experimental station (the Czech Republic) in 2013 andlasted until 2017. The crop rotation consisted of four arable crops: winter wheat, winter barley,rapeseed, and potatoes, but only winter wheat and winter barley are analyzed in this paper (grainyields and crude protein content).In comparison with the Control, the application of mineral fertilizers significantly increased grainyield and protein content of both kinds of cereal. Comparing mineral fertilizers, no significantdifferences were recorded between N, NP, NP+KMgS and NP+MgSMnZn treatments, showingthat nitrogen was the most limiting factor affecting yield and protein content, and initialconcentrations of K and Mg were suitable and capable to cover cereal’s demands. However,application of fertilizers has increased the K and Mg soil content and thus prevents the soil fromthe element’s deficiency, which does not has to be recognized in the early stages by visualobservation of arable plants. The effect of the year was also significant as two out of four seasonswere characterized by high temperatures and drought.