Agroforestry systems: an alternative to intensify forage-based livestock in the Brazilian Amazon

Abstract

Brazil is one of the few countries in the world that can produce animal products, grains, fibers, and bioenergy in the same area, either in a consortium, rotation, or succession. Our objective was to compare pasture productivity and animal performance in agroforestry systems with grass monoculture in the Brazilian Amazon Biome. The experiment was carried out in Sinop, MT, Brazil, with Nellore steers in a continuous stocking with variable stocking rate. The experimental design was a randomized complete block, with four systems and four replicates. The palisadegrass [Brachiaria brizantha (Hochst. ex A. Rich.) R. D. Webster cv. Marandu] was planted in the four systems: livestock (grass monoculture); livestock–forestry [eucalyptus trees (Eucalyptus urograndis; hybrid of Eucalyptus grandis W. Hill ex Maiden and Eucalyptus urophylla S. T. Blake) arranged in three-row groves spaced 30 m apart]; crop–livestock (palisadegrass after two years of crops); and crop–livestock–forestry (palisadegrass after two years of crops with single rows of eucalyptus trees spaced 37 m apart). The herbage accumulation was greater in the systems with the two previous cropping years (crop–livestock and crop–livestock–forestry) than in the livestock and livestock–forestry, in both seasons. In the crop–livestock–forestry, the greatest herbage accumulation associated with the modified microclimate supported the greatest average daily gain (0.750 kg BW day− 1), stocking rate in both seasons, resulting in the greatest gain per area (940 kg BW ha− 1). We conclude that agroforestry systems assure pasture productivity and animal performance similar or greater than livestock (grass monoculture). Furthermore, the combination of two previous crop years and the least tree density optimized the synergy between crop, livestock, and forestry components, improving beef cattle productivity in crop–livestock–forestry systems.