DYNAMICS OF FORAGE BIOMASS ACCUMULATION IN MAIN PHENOPHASES OF A NATURAL MEADOW OF AGROSTIS CAPILLARISFESTUCA FALLAX TYPE IN THE RHODOPE MOUNTAINS (BULGARIA)

Yanko KOZHOUHAROV, Vladimir LINGORSKI

Abstract. The purpose of this study was to establish the changes in biomass productivity and forage chemical composition in main phenophases of vegetation period of a natural meadow Agrostis capillaris-Festuca fallax type in the Rhodope Mountains (Smolyan region, Southern Bulgaria). The greatest dry mass yields (2.91 and 2.68 t.ha-1) were obtained after annually fertilization with N160P80 and N80P80. With advance of vegetation (from complete stalk shooting to complete flowering) was established a decreasing of the crude protein, crude fat and crude ash contents, while in the crude fiber and nitrogen-free extract substances (NFES) was reported an increasing. The most crude protein production was obtained after fertilization with N160P80 (0.89 t.ha-1), and at least in the unfertilized control (only 0.33 t.ha-1). The most feed units (FU) per 1 ha also were reported in fertilization-use N160P80 (2184.33 FU) and N80P80 (1892.00 FU).

Key words: natural meadow, phenophase, biomass accumulation, chemical indicators, the Rhodope Mountains.