The evaluation under grazing of legumes associated with Andropogon gayanus in a tropical savannah environment on the central plateau of Brazil

Abstract

SUMMARYThe persistence and productivity under grazing of seven accessions of Stylosanthes macrocephala, Zornia latifolia and Zornia brasiliensis in combination with Andropogon gayanus (cv. Planaltina) were investigated in small plots at two stocking rates on a low fertility, acid oxisol in the tropical savannah of the centre-west region of Brazil.Two new accessions of S. macrocephala CIAT 2039 (CPAC 1033) and CIAT 2053 (CPAC 1034) were more productive and persistent than the control cultivar Pioneiro. After 4 years there were no differences in dry-matter yield between the two accessions. No anthracnose (Colletotrichum gloeosporioides) problems were noted in these accessions. Animals refused to graze Z. brasiliensis accessions at any time during the trial. Stocking rate effects became pronounced over time and legume contents were highest in the treatment grazed at 3·0 animals/ha. The advantages of the small-plot grazing method used in the experiment are discussed.