Efeitos do nitrogênio, fósforo, calcário e micronutrientes em cultura de arroz irrigada no Vale do Paraíba Rice fertilization: study of the effect of nitrogen, phosphorus, micronutrients and lime

• Main Authors: Norberto Leite, Hermano Gargantini, Luiz S. Hungria, Toshio Igue
• Format: Article
• Language: English
• Published: Instituto Agronômico de Campinas 1970-01-01
• Series: Bragantia
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051970000100025
• ISSN: 0006-8705; 1678-4499

Efeitos das adubações nitrogenada e fosfatada, da calagem e da aplicação de micronutrientes foram investigados através de ensaios de campo em cultura de arroz (Oryza sativa L.), em solos do Vale do Paraíba, no Estado de São Paulo. Os níveis de nitrogênio e fósforo foram de 0, 40 e 80 kg/ha; para o calcário, em solos orgânicos, de 5 t/ha, e nos argilosos de 3 t/ha; os micronutrientes entraram nas dosagens usuais. Os resultados mostraram sempre grande reação ao nitrogênio, inclusive à dose de 80 kg/ha. Para o fósforo, as reações foram muito menores, e somente em parte dos casos houve aumento de produção. Não se observou reação ao calcário e aos micronutrientes.<br>Thirtheen experiments were carried out at several places in the Paraíba Valey, São Paulo State, to study the effects of nitrogen, phosphorus and micronutrients fertilization, as well as of liming, on rice production. Nitrogen and phosphorus were applied at the levels of nihil, 40, and 80 kg/ha. Lime was applied at the levels of 5 and 3 t/ha in the organic and clayey soils, respectively. Seeds of the variety "Iguape-agulha" were utilized. Cultivation was under flooding system. Planting was done directly with the seeds. The results showed a great response of rice production to nitrogen fertilizer, wich was considerable even at higher dosis. Only in 6 out of the thirteen experiments, there was some response to phosphorus. No response to micronutrients or to liming could be noticed.