Strategies of nitrogen fertilization management in Tifton 85 bermudagrass pastures, based on monitoring changes in sward structural attributes demands previous definition of those more appropriate ones. With this purpose an experiment was carried out at the experimental campus of the Rural Federal University, Seropedica, RJ, from October 2006 to January 2007. Treatments consisted of N fertilization at zero; 50; 100 and 150kg N-urea ha(-1), in a single application, several sampling dates, during the pasture establishment, according to an entirely randomized design, with four replications. Treatments were allocated in experimental plots of 4 x 4m, and sampling dates (days after planting, DAP) in sub-plots. The variables studied were: frequency of plants occurrence; sward height, leaf area index (LAI) and interception of photosynthetically active radiation (PAR). The results showed that frequency of occurrence, sward height and PAR interception varied temporally according to a logistic pattern, whose parameters were modified, to a greater or lesser degree, by the nitrogen doses added. Similarly, at 87 DAP, LAI values
