The aim of the study was evaluation of the effect of dressing seed material of spring barley with a humus preparation and foliar potassium fertilization with Drakar on its yield and content of nitrogen, phosphorus, potassium and magnesium in the grain. One-way field experiment was carried out in the years 2006-2008, in Chrząstowo (53°09’ N; 17°35’ E) near Bydgoszcz, on soil classified as mesic Typic Hapludalfs, of a granulometric composition of light sandy loam. The effect of the following was evaluated: humus preparation Humistar (12% humic acids and 3% fulvic acids), used for dressing at a rate of 1 dm3 per 50 kg of barley grain (1), foliar fertilizer Drakar (25.7% K and 3% N), applied at two doses of 2 dm3·ha-1, before flowering and after its end (2), as well as the combined application of Humistar and Drakar (3). The results of using Humistar and Drakar were compared with the control (4) where these preparations were not used. A significant increase was found in 1000 grain weight and yield of barley grain under the effect of dressing the seed material with Humistar. However, this factor’s effect on spike density per unit of area or on the grain number per spike was not indicated. Foliar fertilizer Drakar did not affect significantly the grain yield or its components. The studied preparations did not affect significantly the leaf greenness index in barley in the stage of tillering, shooting and flowering. However, a positive effect of Humistar was found on values of this index in the milk stage. The total nitrogen concentration in barley grain was independent of the used preparations. However, a significant increase in the content of phosphorus and magnesium was found in barley grain dressed with Humistar. Concentration of phosphorus and potassium in barley grain on plots with a foliar fertilization with Drakar was lower, while of magnesium higher than on the control.

153-162