Nitrogen Fertilization in the Initial Growth of Khaya senegalensis A. Juss Plants Under Greenhouse Conditions

African mahogany is an exotic specie and its cultivation has increased in Brazil due to the high value of its timber on the international market. Nutrition with nitrogen is an important factor for species with high biomass production and specific studies on this species are essential. The present study aimed to assess the initial growth of African mahogany plants submitted to nitrogen fertilization. The experiment was set up and carried out in a greenhouse, with 7 dm3 plastic pots using a oxisoil sampled from the surface layer. A completely randomized experimental design was used with five treatments and six replications. The treatments consisted of five N levels: 0, 40, 80, 120 and 160 mg dm-3, using urea as the source. The following were assessed at 180 days: height, stem diameter, leaf, stem, root and total dry matter, N content in the leaves in the African mahogany leaves. The African mahogany seedlings had high N demand and responded positively to the N used and the growth variables was positive with increase in N level. However, as it presented increasing linear effect, the N level can not be estimated, that would provide the maximum initial development for this plant species.