Nutrient cycling in sugarcane. I. Plant recovery of N from single or split urea (15N) application

• Autor(a) principal: Sampaio, E. V.S.B.
• Data de Publicação: 2014
• Outros Autores: Salcedo, I. H., Bettany, J.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/15991
• topic: absorção de N; curva de crescimento; partes da planta

A fiel experiment was established, on a Podzolic Red-yellow soil in Goiana, PE, Brazil, with three tretments: 1) no nitrogen; 2) 60 kg/ha of 15N at planting time and, 3) 20 kg/ha of 15N at planting time plus 40 kg/ha of N three months later. Each plot had nine rows, 10 m long, and received liming plus 120 kg/ha of P2O5 and 100 kg/ha of K2O. In each plot receiving N, urea with 10,2% of 15N atom excess was added to two subplots, 1,25 by 1,25 m each. Nitrogen derived from fertilizer (Ndff) and total N in green and dry leaves, stalks and roots were determined 3, 6, 11 and 16 months after planting. Neither dry matter production nor N content in the different plant parts varied significantly among treatments, in any of the four sampling periods. At harvest time, cane production was 130 t/ha and N uptake was 250 kg/ha. Less than 10% of the N was derived from the fertilizer and absorved during the first three months of the growing period, Ndff percentages in the plants were proportional to 15N application rates, resulting in fertilizer efficiencies of about 40%. Different plant parts had different percentages of Nddf.