Estrutura da pastagem, fotossíntese e produtividade de gramíneas forrageiras

Resumo

Efficient and sustainable pasture management can be characterized as the control of the pastoral system, aiming at its greater production, better utilization and persistence, with positive impacts on animal performance. Forage production stems from the transformation of solar energy into organic compounds from photosynthesis, where the carbon from the carbon dioxide (CO2) of the atmosphere is combined with water and converted into carbohydrate, with the utilization of solar energy - a process responsible for more than 90% of the biomass accumulation in plants. Factors such as light, water and nutrients affect the photosynthetic potential of the forage plant, as a result from alterations in its leaf area and the sward photosynthetic capacity. Regarding its unlimited availability, light radiation is one of the determinant factors to plant growth, through its effect on photosynthesis and other physiological processes, such as transpiration and water and nutrient absorption. The selection of forage germplasm, with plant architecture and sward canopy which maximize light interception and utilization is a competitive advantage, promoting greater efficiency at the transformation of light energy into chemical energy. In this context, adequate management practices are essential to optimize generation and dynamics of tissue flow in the pasture ecosystem, so as to balance the conflicting demand of plants for leaf area and its constant removal through animal intake.