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.