The use of lowland areas in the Central Depression of Rio Grande do Sul State, Brazil is basically limited to irrigated rice. Those areas stay on fallow during the winter due to lack of a good natural drainage. Improvement in drainage can be obtained througth area leveling and microrelief correction associated to the establishment of superficial drains. Therefore, an experiment was conducted in order to evaluate cattle production on a leveled lowland area with several grazing winter plant species under different fertilizer rates. The experiment was conducted at the Federal University of Santa Maria in a soil of the Vacacaí mapping unit. The area was leveled with a 0.06% slope gradient and the plant species were ryegrass (Lolium multiflorum), white clover (Trifolium repens) and birdsfoot trefoil (Lotus corniculatus). The fertilizer levels were 50%, 100% and 150% of the official recomended rate and the soil had its pH corrected to 5.5 using limestone. The experiment design was a randomized block with two replications and each experimental unit measured 0.5ha. The beef calves had 8-10 months of age and placed under continuous grazing, with 480 kg ha-1 of live weight for treatment. The parameters evaluated were: individual daily weight gain, animal load, weight gain per area, average dry matter accumulation by the pastures, in vitro digestibility, protein and botanical composition. The dry matter of the pastures was around 1000kg ha-1 and average accumulation for dry matter of the pastures was 19.9kg ha-1 day-1. The average weight gain per animal was 1016g animal-1 day--1, with an average load 738.6kg per hectare and the average weight gain was 469.7 kg ha-1. The total number of grazing days were 98, 121 and 128 for the 50, 100 and 150% recommended fertilizer rates. The NPK fertilizer levels, keeping constant the nitrogen fertilization, didn´t affect the average daily weight gain, animal load and weight gain per area.
mixture; ryegrass - white clover - birdsfoot trefoil; set-stocking; pasture
