Bases para defini??o de doses de ureia em experimentos em casa de vegeta??o e avalia??o de fertilizantes nitrogenados com base na ureia acrescida de subst?ncias h?micas e ze?lita

• Ano de defesa: 2014
• Autor(a) principal: Ferrari, Anderson Claiton
• Orientador(a): Zonta, Everaldo
• Banca de defesa: Zonta, Everaldo, Alves, Bruno Jos? Rodrigues, Teixeira, Paulo C?sar
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Agronomia - Ci?ncia do Solo
• Departamento: Instituto de Agronomia
• País: Brasil
• Palavras-chave em Português: Ureia; Am?nia; Subst?ncias h?micas
• Palavras-chave em Inglês: Urea; Ammonia; Humic substances
• Área do conhecimento CNPq: Agronomia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/2795

Urea is the most widely used nitrogen fertilizer; however, it has major nitrogen losses through ammonia volatilization. The application of urea in maize can cause injuries, especially during the initial period of development due to the salt effect and volatilization of ammonia. Materials with high CTC and acid character, has been reported in the literature as potential for reducing N loss through ammonia volatilization. This work aims in Chapter I, to evaluate and compare the effects of different doses of urea calculated based on the surface area of the pot, on the soil volume and the number of plants per pot, on the initial growth of maize to the V8 stage, to establish a criterion for calculating fertilizer rates used in the greenhouse, which are equivalent to those applied in the field, thus enabling to study the effects of nitrogen fertilization. Chapter II aimed to verify the loss reduction effect of N NH3 through fertilizer formulation containing humic substances and zeolite mixed with urea, as well as studying the alkaline extraction of humic peat, which enables higher performance with lower consumption extractor. Two experiments were conducted in pots in a greenhouse, in the Department of Soil Science, UFRRJ, using the maize hybrid AG1051. Collections of plant material, soil and volatilized ammonia were performed. In Chapter I, the largest urea dose applied, based on the number of plants, negatively affected the germination and was responsible for major losses by volatilization. For development up to V8, the largest amount of urea, obtained by taking the number of plants and the highest dose of 50 kg N ha-1 led to higher losses via volatilization, but it was sufficient to provide nitrogen for the plant. In Chapter II, the formulations did not differ with respect to loss by volatilization of ammonia, leaving it to the higher doses applied the greatest influence on the loss of N and on other parameters. There was a trend of lower accumulated loss by volatilization of N, for formulations which had in their composition humic substances and zeolite. Although it reduced losses by volatilization, the obtained fertilizer rates, considering the exposed soil area were not sufficient to ensure a good potential yield for the crop, according to the indirect measurement of chlorophyll.