Influencia de la calidad del terreno en la respuesta de los pastos a la aplicación de fósforo

Abstract

In the southwest of Extremadura pastures show a very irregular production and low nutritional value. In this zone, farmers classified their farm’s areas in bad and good, and fertilization with phosphate is made only in good areas. In this study we evaluated the soil quality influence on the pasture improvement when phosphoric fertilizer was used. The experiment was conducted in two farms in the region of La Serena (Badajoz), where the main plot was the quality of the soil differentiated based on slope, depth and stoniness, and the sub-plot was the fertilization. Superphosphate of lime to 18% at a rate of 250 kg ha-1 was applied, having a control area without fertilization. This experiment was replicated in three different agro- nomical years, and the botanical composition of pasture, the production in dry matter, the crude protein and the organic matter digestibility of grass in winter and spring were analyzed. Protein and digestibility of winter grass in bad areas were improved by phosphorus fertilization (increasing from 15% to 16%) and the percentage of legumes changed from 20% to 30%. There is, therefore, a positive contribution of phosphorus in classified areas as bad by farmers, showing them an improvement potential regarding to pasture quality and botanical composition