Diagnose da composição nutricional e eficiência de fertilizantes nitrogenados na cultura do milho

• Main Author: Modesto, Viviane Cristina [UNESP]
• Publication Date: 2014
• Format: Master thesis
• Language: por
• Source: Repositório Institucional da UNESP
• Download full: http://hdl.handle.net/11449/110330
• topic: Milho - Nutrição; Adubos e fertilizantes; Fertilizantes nitrogenados; Biometria; Fisiologia vegetal; Nitrogen fertilizers

The nitrogen fertilization is the agricultural practice that influences the most the grains yield in the maize culture. Together to the use of technologies the use of fertilizers promotes a better use of N by the cultures. This way, it was aimed evaluate the biometric characteristics, chlorophyll amount, biomass production, and the nutritional status of maize plants when submitted to different sources and doses of nitrogenous fertilizers. The experiment was carried out in a Luvisol, at Embrapa/CNPC Experimental Field in Sobral, CE, Brazil. The treatments were five nitrogen sources: urea + NBPT, urea + polymer, urea + enzymatic inhibitor, urea + sulfur covering, and urea without technology added. Three doses of nitrogen were used: 45, 67,5 and 90 kg N ha-1 and an additional treatment, without nitrogen fertilization, as top dressing 30 days after planting. The nitrogen fertilization combined to technology promoted higher chlorophyll contents and biomass production in the maize plants. The maximum agronomic economic efficiency was reached using urea without nitrogen fertilization, as top dressing 30 days after planting. The nitrogen fertilization combined to technology promoted higher chlorophyll contents and biomass production in the maize plants. The maximum agronomic economic efficiency was reached using urea without technology added, urea + urease inhibitor, and urea + elementary sulfur