Plants of the family Brassicaceae are characterized by high nutritional and fertilization requirements, in particular with respect to nitrogen, potassium, and sulphur. The positive action of the above-mentioned nutrients on plant growth and yield is associated, among others, with their rate and form as well as with interrelationships between individual nutrients. The present experiment was conducted in a greenhouse during the period from March to May in the years 2010 and 2011. Garden rocket plants were seeded individually in 2dm³ pots, with peat as the growing medium. The experimental design included three rates (g dm^-3 of medium) of potassium in the form of K₂SO₄: 0.3 K (and 0.34 S); 0.6 K (and 0.47 S); 0.9 K (and 0.6 S), in the form of KCl: 0.3 K (and 0.27 Cl); 0.6 K (and 0.54 Cl); 0.9 K (and 0.81 Cl), as well as two rates of nitrogen in the form of Ca (NO₃)₂: 0.3 N (and 0.37 Ca); 0.6 N (and 0.74 Ca). The following traits were determined: plant height (cm), number of leaves per rosette (pcs), plant weight (g), and fresh weight yield of leaf rosettes (g ^. pot^-1). The content of N, P, K, Ca and of Mg, S-SO₄, Cl was determined in dried plant material. The increase in the rate of nitrogen in the nutritional environment of rocket did not affect plant height and the number of leaves per rosette, but it caused a significant increase in fresh weight yield of leaf rosettes, as well as it resulted in an increase in calcium content and a decrease in chlorine concentration in the plants. The increased amount of potassium in the medium contributed to an increase in rocket yield as well as an increase in the concentration of potassium and chlorine. Potassium chloride proved to be a better source of K than sulphur due to the amount of fresh weight and yield of the plants studied. The plants fed with KCl were also characterized by a higher content of nitrogen, chlorine, calcium, and magnesium than after the application of K₂SO₄.

289-300