Emissão de amônia e teores de nitrogênio no sistema soloplanta após aplicação de herbicidas dessecantes

• Ano de defesa: 2013
• Autor(a) principal: Pacheco, Lara Cristina Pereira da Silva
• Orientador(a): Damin, Virginia
• Banca de defesa: Leandro, Wilson Mozena, Silveira, Pedro Marques da, Marchão, Robélio Leandro, Damin, Virginia
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Programa de Pós-graduação em Agronomia (EAEA)
• Departamento: Escola de Agronomia e Engenharia de Alimentos - EAEA (RG)
• País: Brasil
• Palavras-chave em Português: Dessecação; Nitrogênio; Perdas; Nitrificação; Micro-organismos
• Palavras-chave em Inglês: Drying; Nitrogen; Losses; Nitrification; Microorganisms
• Área do conhecimento CNPq: AGRONOMIA::CIENCIA DO SOLO
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tede/4434

The nitrogen is one of the nutrients that is more affected by Tillage System and that most limits both crop development and crop productivity. Several factors can modify the N dynamics in areas under Tillage System, however, a factor that has been little investigated is the use of desiccants for formation of stubble on the soil. The desiccant can affect various processes of the nitrogen cycle and, thus, affect the availability of N in agroecosystems. In this context, the aim of this study was to evaluate: 1 - The ammonia emission by plants and soil after application of desiccants in Pennisetum glaucum, and 2 - The effects of herbicides application on Urochloa ruziziensis and Pennisetum in total-N, mineral-N, activity and microbial biomass in soil. Herbicide application on Pennisetum glaucum increases losses of NH3-N by the plant and does not affect the volatilization of NH3-N by soil. Glyphosate reduced content of N in Pennisetum glaucum and all herbicides have reduced the content of nitrogen in the soil when millet was used as cover culture. The same effect on the total N was not observed with Urochloa straw. The herbicides effects on mineral-N were highly variable. Herbicide application in both experiments did not affect the microbial biomass of the soil, while the basal respiration was increased by the application of paraquat on Urochloa ruziziensis.