Simulation model for evaluating sustainability of pastures on the high plains of Colombia I. Development and validation of the model

Abstract

A simulation model was developed for evaluating the sustainability of pastures in the Colombian high plains. The model establishes the relationships among four components. Component (1) the animal, includes intakes of forage dry matter and mineralized salt, grazing system, stocking rate, energy and protein requirements for maintenance and production (liveweight gain); (2) the plant, includes growth, senescence, digestibility and availability; (3) the soil, includes compaction, fertilization and interchange rates for N, P, K and organic matter; and (4) the climate, includes temperature and rainfall. The model evaluates sustainability over time considering animal weight gain, pasture growth, soil compaction and soil nutrient translocation. Results obtained with the model were compared to those obtained experimentally in the area and a low percentage of estimated error was found. It is concluded that the model adequately evaluates the functioning and sustainability of this production system.