Urea as a source of nitrogen in physiology and initial growth of Guazuma ulmifolia Lam. (malvaceae)

• Autor(a) principal: Silva, Patrícia Oliveira da
• Data de Publicação: 2020
• Outros Autores: Carlos, Leandro, Costa, Andreia Mendes da, Dias, Jorciane Souza, Veneziano, Vitor Martins, Rodrigues, Carlos Ribeiro
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Ciência Florestal (Online)
• Texto Completo: https://periodicos.ufsm.br/cienciaflorestal/article/view/42643
• topic: Mutamba; Nitrogen fertilization; Physiological variables; Mutamba; Adubação nitrogenada; Variáveis fisiológicas

The aim of this study was to determine how Guazuma ulmifolia seedlings respond to nitrogen doses, with urea as a nitrogen source (N). The seedlings were cultivated in a completely randomized design, which were subjected to five doses (0, 50, 100, 150 and 200 mg dm-³) of N. At 120 days of cultivation, biometric, physiological, biomass accumulation, allometric ratios, Dickson's quality index (IQD), content, accumulation and N efficiency use (NUE) in the aerial part of the seedlings. The data were submitted to analysis of variance and regression. In addition, Pearson's correlation coefficient was also analyzed. The N doses significantly promoted (p≤0.05) the increase in the N content in the aerial part of the seedlings. On the other hand, there was a significant reduction in the N accumulation, of physiological variables, growth, biomass, IQD and NUE, which resulted in a negative correlation with the increasing N supply. Very high N doses, having as source the urea, were harmful to the seedlings of Guazuma ulmifolia. The doses between 20 and 38.8 mg dm-³ of N, in general, were those that promoted the best results.