Estrategias de mejora en la producción de biomasa herbácea y de su calidad nutritiva en pastizales y pastos de dehesa en clima semiárido mediterráneo

Abstract

With the aim of increasing the feeding resources for livestock in grasslands and dehesasunder Mediterranean semiarid conditions, an essay was performed to evaluate theinfluence of several strategies for the improvement of forage biomass yield and severalnutritive value parameters during two farming years (2002/03 and 2003/04). Theimprovement treatments were the following: sown meadow (with 2 different sowing mixand by using two cropping technologies) and phosphoric fertilization (phosphorite andsuperphosphate). The treatment effect was analyzed in the whole pasture and its fractions(legumes, grasses and other herbs). The sown meadows, by using either subterraneumclover or a biodiverse species mix, increase the forage yield by a 37% in the most favorablecase, regardless the crop technology used. Either the sown meadows or Superphosphatefertilization, improved also the feeding quality of the forage, especially protein content orcrude energy, although the intensity of the improvement was regarded to the specificclimatological conditions of the study year. The organic matter digestibility was notaffected by the improvement treatment. As a conclusion, the pasture improvement leadsto an increase in forage yield and a better nutritive value, which might reduce the necessityof supplemental feeding.