Nitrogen and sulphur for productive characteristics of signalgrass from degrading pasture area

The objective of this work was to evaluate the effects of combined rates of N and S on signal-rass (Brochiaria decumbens) productive characteristics. This grass was collected ill cylinders with soil + plants in a degrading pasture established in all Entisol. The experiment was carried Out ill a greenhouse. at Piracicaba, SP, Brazil, from November 2003 to March 2004. Five rates of N (0, 100, 200, 300 and 400 mg/dm(3)) were combined with five rates of S (0, 10, 20, 30, and 40 mg/dm(3)) in a fractionated 52 factorial, based on a central composite design. Plants were harvested following three periods of 30 days growth. The combination between N and S rates affected tile number of tillers, dry matter yield of leaf blade and stems plus sheaths at tile first harvest and the leaf blade: sterns Plus sheaths ratio at tile second lijivest. Nitrogen rates had effects oil the IlUrnber of tillers and oil dry matter yield of leaf blade and stems plus sheaths at the second and third harvests. At the first growth. the leaf number of the grass was changed by both N and S rates. and by N rates at the second and third Irowths. Maximum dry matter yields were reached when N and S rates were applied at about 10:1 ratio. The application of mainly N, but also of S. affected the productive characteristics of signalgrass, and its recovery.