The objective of this experiment was to evaluate the animal productivity and economic return of the use of urea or ammonium sulfate for fertilization of oat (Avena strigosa Schreb) plus ryegrass (Lolium multiflorum Lam.) pasture. The pasture was established on 04/21/94 and the grazing period occured from 06/05 to 11/06/94. The continuous grazing method with variable stocking rate was used. The animals used were beef heifers, with 10 months of age. The amount of nitrogen used was 200 kg/ha, subdivided in three applications. The source of nitrogen did not significantly affect the average daily gain, .579 and .615 kg, the stocking rate, 873 and 842 kg of live weight/ha and the live weight gain/ha, 428 and 453 kg/ha, for urea and ammonium sulfate, respectively. Nitrogen fertilization represented 34.10 and 47.56% of the total cost of the pasture, when urea and ammonium sulfate were used, respectively. The gross income was of U$ 299.50 and 318.00/ha and the net income was of U$ 47.90 and 1.90/ha, for urea and ammonium sulfate, respectively. Since no significant difference occurred in live weight gain/ha, the decision of using urea or ammonium sulfate for fertilization of annual winter pasture should be based on the price per kg of nitrogen.
ammonium sulfate; animal performance; cost; cultived pasture; gross income; grazing; net income; urea
