Caracterização de fertilizantes orgânicos e organominerais fluidos

• Autor(a) principal: Dominguez, Danielle Xanchão
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15788
• topic: Organic fertilizers; Organic matter; Carbon; Liquid fertilizers; Fertilizantes orgânicos; Matéria orgânica; Carbono; Adubos e fertilizantes líquidos; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA

The use of organic and organic-mineral fertilizers has grown fastly in the world and also in Brazil in the last two decades. This fast increase in the demand for these products took the Ministry of Agriculture to search new methodologies for the verification of their quality. This work has objective of obtaining information on the nature of these fertilizers, by evaluating existing methodologies and testing new ones, contributing to the development of a quality control protocol to be adopted by the Ministry of Agriculture and the producing companies. In a first stage, the fertilizers were characterized by means of physical and chemical analyses as the foreseen methods of routine in the legislation. Additionally, different methods of carbon determination were evaluated, beyond the humic substances fractionation in the samples of fertilizers, and posterior determination of the carbon in the humic and fulvic fractions. The most reactive functional groups in the samples were identified and quantified by potentiometric titration. The humic acids of fifteen fertilizer samples were extracted and purified. The humic acids were characterized by infrared spectrometry (FTIR) and elemental analysis (CHN). The evaluated fertilizers presented a large variation in relation to the analyzed characteristics. Large variations in relation to the levels of organic carbon and total carbon were observed, as well as in the quality of organic compounds in fertilizers that was reflected in its agronomic efficiency. By the correlation between the used methods, it was observed the possibility of substitution of methods of difficult execution for simplified methods of low cost allowing their application in routine analyses. New studies including a more representative set of samples must be carried out in order to determine parameters for the different chemical and physical attributes of these products given technical subsides to the legislation.