Novas tecnologias em fertilizantes nitrogenados : volatilização de amônia e produtividade do cafeeiro conilon

• Ano de defesa: 2018
• Autor(a) principal: Machado, Ramires Ventura
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Doutorado em Agronomia; Centro de Ciências Agrárias e Engenharias; UFES; Programa de Pós-Graduação em Agronomia
• Palavras-chave em Português: Nitrogênio; Ureia; Café conilon; Fertilizante nitrogenado; Nitrogen; Urea; Conilon coffee; Nitrogen fertilizer; Agronomia
• Link de acesso: http://repositorio.ufes.br/handle/10/17882

Urea is the most used nitrogen fertilizer in Brazil and in the world, but its superficial application may result in losses due to volatilization of ammonia, due to the action of urease. The growing demand for food associated with the concern of society with the environment has encouraged the search for new technologies to reduce the losses associated with the application of fertilizers, especially nitrogenous ones. The aim of this study was to evaluate the dynamics of nitrogen, from the application of new technologies associated with nitrogen fertilizers. For this the present thesis is structured in 4 chapters. Chapter 1 relates to a laboratory experiment in a 5 x 2 x 2 factorial scheme, with 5 nitrogen fertilizers (conventional urea (UA), urea + boron and copper (UBC), urea + urease inhibitor - NBPT (UNBPT) , and 2 fertilizers with sulfur-polymer coated urea (UPS1 and UPS2), 2 matric potentials (-30 kPa and -75 kPa) and 2 forms of application: Form 1 (100% of the dose applied uniquely at the beginning of the experiment) and Form 2 (50% at the beginning of the experiment and 50% at 7 days), aiming to quantify losses by volatilization of NH3 from the application of fertilizers with associated technology submitted to different matric potentials and application forms. Chapter 2, also performed in the laboratory, besides quantifying NH3 volatilization, also determined the urease activity and soil CO2 flux using 4 nitrogen fertilizers (conventional urea (UC), urea + boron and copper (UBC), urea + urease inhibitor - NBPT (UNBPT) and urea coated with sulfur and polymer (UPS) and the same application forms used in chapter 1. Chapter 3 refers to a greenhouse experiment to evaluate the initial growth of conilon coffee as a function of the application of new technologies in nitrogen fertilizers submitted to different matric potentials. The same fertilizers used in chapter 2 and two different matric potentials were used -75 kPa and -150 kPa. Chapter 4 was carried out from an experiment in the field to evaluate the nutrition and production of conilon coffee from the application of technologies in nitrogen fertilizers submitted to different forms of application. The fertilizers used were the same as in Chapter 3 and the application forms were 100% of the nitrogen fertilization in single application; 50% of the nitrogen fertilization applied in the flowering and 50% in the grains formation; and 65% of nitrogen fertilization applied in flowering and 35% in grains 10 formation. Chapter 1 demonstrated that new technologies in nitrogen fertilizers reduced the volatilization of N-NH3, where the polymer and sulfur coated fertilizers presented lower losses due to volatilization of N-NH3. The treatments with higher matric potential (-30 kPa) reduced the volatilization of N-NH3 by 16.3% and the single fertilization (100%) presented on average losses by volatilization of N-NH3 23.5% lower. In Chapter 2 it was observed that technologies applied to nitrogen fertilizers (UBC, UNBPT and UPS) reduced losses by volatilization by 40% and soil urease activity by 22% when compared to UC, with UPS being the fertilizer received the best evaluation. The split reduced N-NH3 volatilization losses by 36.1 and 65.2% for UNBPT and UPS fertilizers respectively, and the CO2 flux did not change as a function of the treatments. Chapter 3 concluded that nitrogen fertilizer technologies influenced the initial growth and nutrition of the conilon coffee tree, increasing leaf area (8.8%), leaf dry matter (9.7%) and stem (11.8%), and N content in the dry matter in the leaf (12.9%). The UC, UBC and UNBPT were influenced by a higher matric potential (-75 kPa). The UPS was not influenced by the soil matric potential. Chapter 4 demonstrated that nitrogen fertilizer technologies applied to conilon coffee produced 17 bags per hectare more than conventional urea. There was no difference between N fertilizer technologies when evaluating the productivity and concentration of total N and P in the leaves of conilon coffee, and that the application of each nitrogen fertilizer did not influence the productivity and nutrition of conilon coffee