摘要：The objective of this study was to determine the effect of the biostimulant Kelpak SL as well as nitrogen fertilisation on the concentration of some macroelements in two species of grass. A field experiment was arranged as a randomized subblock design (split-split-plot) with three replicates at the Siedlce (Poland) Experimental Unit of the University of Natural Sciences and Humanities in late April 2009. The following factors were examined: pure stands of grass species grown in monoculture - Dactylis glomerata L. cv. Amila and Festulolium braunii (K.Richt.) A. Camus, cv. Felopa; biostimulant with the trade name Kelpak SL applied at 2 dm3-ha-1 and a control - no biostimulant; nitrogen application rate: 50, 100 and 150 kg .ha-1, and a control (0 kg . ha-1). An application of Kelpak and nitrogen fertilisation contributed to an increase in P, Ca and Mg contents and a decline in K contents in the biomass of grass species tested. Increasing rates of nitrogen fertiliser were followed by increased P, Mg and Ca contents and reduced K content in the plants tested. The concentration of macroelements in the biomass of grasses was almost optimum. An application of seaweed extract and nitrogen fertilisation clearly extended Ca:Mg and Ca:P ratios but narrowed the K: (Ca+Mg) ratio.
