Pasture productivity relies heavily on exchange of several different compounds between roots and shoots. The study aimed to evaluate nitrogen content on Marandu-grass pasture managed under 3 grazing management heights. The heights of 15, 25 and 35 cm were managed by beef steers grazing under continuous stocking and occurred from January to November, 2011. Data were analyzed by repeated measurements with grazing intensity, period and interactions. Roots and shoots samples were collected monthly. The collected samples were washed, dried and ground for further analysis. Total nitrogen concentration in the shoots was higher during the summer (14.77 g kg⁻¹ DM) and lower during the drier seasons (7.47 g kg⁻¹ DM) (P < 0.05). This decrease in concentration was more marked for the 35 cm pasture height (P < 0.05). Total nitrogen concentration in the roots followed the opposite pattern, increasing in drier seasons (7.29 g kg⁻¹ DM), and had no consistent correlation with pasture height. Root nitrogen content was also negatively correlated with precipitation and temperature, while shoot nitrogen was positively correlated (P < 0.05). During the summer, fertilizer application along with temperature, precipitation and insolation favor plant growth. With a higher quantity of new leaves in this season there was an increase in shoot nitrogen content. During the winter, limited growth favors nitrogen storage in roots. Our results indicate that roots provide a storage site for nitrogen during drier, less favorable seasons. These reserves were directed to shoot regrowth during the summer. We found a negative linear association between pasture heights and shoot nitrogen content in autumn and winter (P < 0.05). In more intensely managed pastures, greater tissue renewal occurs as tillers develop in an environment with reduced competition for light. Indeed, intensely managed palisadegrass pastures have higher rates of tiller appearance and death, and higher defoliation frequency of individual tillers. In addition, taller pastures carry a higher proportion of stem and dead material in relation to shorter pastures, contributing to lower nitrogen concentrations. Root nitrogen did not show a consistent response pattern in relation to pasture height.