Evaluación de gramíneas en pastoreo en suelo Fersialítico Rojo Parduzco Ferromagnesial de un ecosistema de sabana.

The behavior of six improved grassies under cutting on a lower-fertility red-brownish ferromagnesial fersialitic soil was studied. A completely randomized design with three replicas consisting in 0,25 ha spots under grazing conditions every 30 to 35 days during rainy season and 40 to 50 days during dry season with 12 lambs/ha load was applied. Grassy species were fertilized with N, P, and K at a ratio of 100; 80 and 100 kg/ha/year, respectively. Nitrogen was fractionated during the rainy season. Availability was measured by rotational grazing, and botanical composition was determined at the initial and final stages of the experiment. Andropogon gayanus cv. CIAT 621 showed the highest dry matter availability, followed by Brachiaria decumbens cv. CIAT 606, which showed no significant differences in relation to Andropogon in the first year during the rainy season and the second and third years during the dry season. In contrast, Brachiaria purpurascens cv. Aguada showed the worst behavior to the above mentioned index. Andropogon and Brachiaria 606 endurance was higher (P<0,001), but the other species population decreased by the third year. It is recommended to spread Andropogon gayanus cv. CIAT 621 and Brachiaria decumbens cv. CIAT 606 over the region due to edaphic and climatic conditions in this place. [ABSTRACT FROM AUTHOR]