It is important to define nitrogen management strategy for upland rice crop, because nitrogen is the nutrient more absorbed by rice plants and, due to the ease of leaching in soil, it can pollute the environment. This study aimed to simulate, based on ORYZA/APSIM 2000 model, different strategies for nitrogen fertilization management to maximize the productivity and minimize the N leaching. In the simulation, five application modes with an application rate of 100 kg N ha-1 were considered: TP - 1/5 at sowing, 2/5 at the beginning of tillering (T) and 2/5 at panicle differentiation (P); T1 - all at sowing; T2 - all at 20 days before sowing; T3 - 1/5 at sowing and 4/5 at T and T4 - 1/5 at sowing and 4/5 at P. Application modes were combined with five sowing dates: 01/11, 15/11, 01/12, 15/12 and 31/12. Nitrogen fertilizer split applications showed to be the strategy most likely to result in high yields of upland rice. When this strategy is not used, the probability of nitrogen losses by leaching is higher. There is higher probability of obtaining higher yields in the earliest sowing dates, from 01/11, despite the late sowing contribute to reduction in nitrogen losses by leaching.
Oryza sativa; nitrogen fertilization; N leaching; sowing date
