摘要
Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.
Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.
