Nitrogênio (15 N) e atividade das enzimas redutase do nitrato e glutamina sintetase na cultura do milho em plantio direto

• Ano de defesa: 2008
• Autor(a) principal: Santos, Manoel Mota dos
• Orientador(a): Galvão, João Carlos Cardoso
• Banca de defesa: Berger, Paulo Geraldo , Souza, Leandro Vagno de , Fontanetti, Anastácia
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Zea mays; Época de aplicação; Adubação nitrogenada
• Palavras-chave em Inglês: Zea mays; Application time; Nitrogen; Manuring
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1108

This work was developed using data of the rehearsal conducted in the experimental station of Coimbra MG, area belonging to Federal University of Viçosa. It was aimed at through this theory: 1 - to evaluate the effect of the Nitrogen manuring on the activity of the enzymes nitrate redutase (NR) and Glutamina sintetase (GS) in corn cultivars in reduced spacing and 2 - to evaluate the effect of the time of application of Nitrogen, enriched with 15N, on the productivity of grains and it s distribution along the plant, in the presence and Molibdenium absence in system of direct sowing in the culture of the corn. To reach the 1 main, the experiment was conducted using two corn cultivars (AG 9010 and P 3041) and for the conclusion of the objective 2, the experiment was accomplished just by using AG 9010 cultivar, however using the same area. The planting was accomplished in November staying a population of 50.000 plants ha-1. The experimental portion was composed by eight lines of 5,0 meters in length with spacing of 0,50 m among the planting lines. The useful area was 12 m2. The planting manuring was accomplished with 380 kg ha-1. of the formulation 8 -28 -16 for the plots that received Nitrogen. For the zero dose of Nitrogen the manuring was accomplished with 106 kg of P2O5, in the form of Simple Superfosfato and 60 kg of K2O, as Chloride of Potassium, in the plots. The covering and planting manuring with Nitrogen was accomplished with urea, using 150 kg ha-1, accomplishing irrigation just after the application of urea, according to description of each treatment. The time of application of the Nitrogen interferes in the independent enzymatic activity of the manuring with Molibdenium. The largest productivity of grains and larger activity of the redutase of the nitrate was obtained with the application of Nitrogen at time the corn presented with four leaves completely expanded. There was difference in the enzymatic activity among them cultivars, influenced by the vegetative cycles. The best supply of N during the cycle and the largest productivity was obtained with the application of the fertilizer in the stadium of four expanded leaves of the corn. It was not found effect of the manuring of Molibidenium on the appraised characteristics. The application of N in the pre- sowing of the corn, 15 days before the planting, it demonstrated not to be advisable for the soil conditions and climate studied. The part of the corn plant with larger allocation of N was the grain. The medium recovery of Nitrogen in the originating from plant the fertilizer, was 6%. The medium amount of Nitrogen in the originating from plant the fertilizer, was 9,21 kg ha-1, but when of the application of urea in the stadium of four leaves the recovery arrives around 16%. The organic matter of the soil is the main source of N for the corn plants.