Modelling the growth and utilisation of kikuyu grass (Pennisetum clandestinum) under grazing. 2. Model validation and analysis of management practices

This paper presents validation results and some management applications of a Tropical Pasture Simulator. The effects of different environmental condit ions, N fertilisation regimes and grazing intensities are analysed, and phy siological concepts are used to aid in the interpretation of the responses obtained. The model demonstrates the importance of flexible management guid elines depending on environmental conditions, It stresses the need for an i ncreased understanding of the processes controlling the development and sen escence of the sward, since these largely influence the responses to nutrie nts and determine sward structure. Strategies based on morphological indica tors such as number of live leaves were derived in order to develop simple and applicable pasture management guidelines at the farm level. Examples ar e presented with reference to kikuyu grass (Pennisetum clandestinum) produc tion and utilisation in dairy systems in the highlands of Costa Pica. (C) 2 000 Elsevier Science Ltd. All rights reserved.