Sustainability of Brachiaria dictyoneura in three contrasting soils of the Colombian high plains. II. Experimentation with a simulation model

Abstract

A validated simulation model was used to evaluate over a 10-year period, the levels of N, P, and K and degree of soil compaction, growth of B. dictyoneura, and weight gain of steers, under a production system typical of the Columbian high plains. The simulation experiment used a 10 × 3 factorial design, one factor being years and the other soil texture. The latter was defined as clayey, loamy or sandy according to sand content (20, 38, and 70%, respectively). A management system was simulated in which steers are put on pasture at the beginning of the dry season (December) for at least four months, at a stocking rate equivalent to one animal per hectare (until late March), and then until the end of the rainy season at two animals/ha. The results indicate that, based on weight gain, stability of soil nutrients, and degree of soil compaction, B. dictyoneura pastures are best suited to soils with 38% sand. This texture is associated with better pasture stability after 10 years, and less progressive reduction in pasture growth, than the other soil types simulated.