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.

DYNAMICS OF FORAGE BIOMASS ACCUMULATION IN DECADES OF A NATURAL MEADOW OF AGROSTIS CAPILLARIS-FESTUCA FALLAX TYPE IN THE RHODOPE MOUNTAINS

Yanko KOZHOUHAROV, Vladimir LINGORSKI

 Abstract. The purpose of this study was to establish the changes in productivity and chemical composition of forage biomass in decades of vegetation period of a natural meadow Agrostis capillaris-Festuca fallax type in the Rhodope Mountains (Smolyan region, Southern Bulgaria). The productive potential of the grass stand was dependent on age of the grasses and the level of mineral fertilization. The greatest yields were obtained after fertilization – 3.92 t.ha-1 (N160P80) and 3.68 t.ha-1 (N80P80). Most crude protein (320-325 g.kg-1 dry matter) contained the forage at the beginning of grass vegetation, while in the same period the crude fiber were at least. It was observed an opposite dependence with advance of vegetation. With the same period, the crude fat content decreased significantly but this reduction was greater in unfertilized control. Nitrogen-free extract substances content increased with the age of grasses and decreased with increasing of mineral fertilization levels. This chemical indicator varied from 350 g.kg-1 dry matter after N160P80-fertilization to 370 g.kg-1 in control. The advance of vegetation had a negative effect on the crude ash content as at the end of vegetation period it decreased almost 3 times. The crude ash values varied in small limits – from 81 g.kg-1 dry matter (N160P80) to 90 g.kg-1 (in unfertilized control). The greatest values of the crude protein yields were reported between 71st–92nd day (from 91.9 to 97.0 t.ha-1) after N80P80-and between 71st–102nd day (from 105.9 to 110.5 t.ha-1) after N160P80-fertilization. Most feed units per 1 ha were obtained after fertilization with N160P80 – 2509.4 FU and with N80P80 – 2225.5 FU.

Key words: natural meadow, forage biomass, decade accumulation, indicators, the Rhodope Mountains (Southern Bulgaria).

INFLUENCE OF MINERAL FERTILIZATION AND WAYS OF USE ON NATURAL MEADOW OF AGROSTIS CAPILLARIS–FESTUCA FALLAX TYPE IN THE RHODOPE MOUNTAINS (SOUTHERN BULGARIA)

Yanko KOZHOUHAROV, Vladimir LINGORSKI

Abstract.The experiment showed that the application of mineral fertilization up to N160P80 increased dry matter yields between different ways of use as follows: from 5.88 to 6.45 t.ha1 (annually hay–pasture uses), from 4.72 to 5.21 t.ha1 (annually pasture–hay uses) and from 5.84 to 6.40 t.ha1 (1st year: pasture–hay uses; 2nd year: only pasture use; 3rd year: hay–pasture uses). As regards to studying chemical indicators of the forage (crude fiber, crude fat, crude ash and nitrogen–free extract substances) the mineral fertilization and alternation of ways of use had a positive effect. The introduction of mineral fertilizers at a rate up to N160P80 increased the obtained feed units and crude protein per 1 ha.

 Key words: natural meadow, mineral fertilization, ways of use, productive and chemical indicators, the Rhodope Mountains.

ftxt