Composición nitrogenada de algunas plantas del Somontano oscense

Abstract

[EN]The crude protein (C.P.), minerals (ash) and dry matter (D. M.) content have been determined in the fresh biomass of 25 wild plants, belonging to 12 botanical families, widely distributed on untilled areas of the Somontano oscense. All these species were selected to be eaten by domestic animals. The same determinations were made in forages provided by 3 cultivated plants: lucerne, barley and vetch. Samples for analysis were taken in late spring and in summer-time. In the case of lucerne a second recovery was made 13 days after the first one. In five of the wild plants (Silene vulgaris (Moench) Garcke, Brachypodium phoenicoides (L.) Roemer & Schultes, Elymus pungens (Pers.) Melderis, Dorycnium pentaphyllum Scop. and Populus deltoides Marshall) the interval between first and second harvest was 35 days. Herbaceous spp. were cut down at 4 cm. from the soil surface. From the shrubs the young and tender regrowths were taken. Samples from the trees consist exclusively on young leaves. In uncultivated plants C.P. content ranged from 8,1% in Dactylis hispanica Roth to 26,1% in Vicia sativa L. calculated on the D.M. basis. In this last specie (Vicia sativa L.) and in Atriplex halimus L. protein content was higher than in cultivated plants. Other wild spp. give also good percentages of protein: Silene vulgaris (Moench) Garke (23,2), Populus deltoides Marshall (19,8), Melilotus alba Medicus (18,3), Euphorbia serrata L. (17,9). In all plants recovered at two differet dates C.P. decreased with development, ash increased in all except in Dorycnium pentaphyllum Scop., and D.M. increased in all.