In order to further develop nutrient management, it is necessary to determine nutrient concentrations which characterise the nourishment level of crops and correlate with the expected yield as much as possible. It is a known fact that potassium is an indispensable element of several processes of crop physiology.

The aim of this study is to look for a correlation between the applied nutrient treatments and the level of crop nourishment.

The culture dish experiment was established in the spring of 2006, in greenhouse environment on lessivage brown forest soil. The selected test crop was the Scarlett variety of spring barley (Hordeum vulgare L.). Eight NPK treatments on two NP levels with increasing K doses were applied in addition to the non-fertilised control plot. Examinations were carried out in different development stages on main crop parts.

The highest K concentration can be shown at the tillering stage and the highest measured K concentration as a result of the applied treatments was 6.6% which was observed in the case of the N2P2K3 treatment. The K content of the flowering ear was nearly identical (between 0.81–0.90%), independently of fertilisation. With the exception of K0 treatments, the measured K concentrations fall into the adequate and high category. The results of the correlation analyses also show that there is a close correlation between the K content of crops and the increase of dry weight. Different treatment doses and ratios strongly influence the quantity and distribution of K that each crop part takes up at different development stages, as well as their dry weight and moisture content.

Keywords: culture dish experiment, NPK fertilisation, spring barley, vegetable product