Alterações de propriedades químicas do solo e nutrição do milho após adição de sienito nefelínico e ácidos húmicos

Abstract

A Deus todo-poderoso pois nada seria possível sem fé.A meus familiares e minha mãe Nair Santos pelo eterno apoio.Ao prof. Dr. Jader Busato, pela orientação e ensinamentos proporcionados.Ao prof. Dr. Fernando Sodré, pela co-orientação e o apoio oferecido. Aos colegas doLaboratório de Química e Física do Solo: Alan Mól, Eduardo Marinho, Lucas Leal e Lucas Melo, esse trabalho seria impossível sem ajuda deles. Aos colegas do AQQUA, Victor e Thiago pela parceria. Ao agrônomo Josiel Pereira que ajudou na montagem do experimento da casa de vegetação. Ao pesquisador Dr. Éder Martins pelo apoio técnico na Embrapa Cerrados.Aos colegas de pós-graduação Miguel Vieira, Geraldo Lopes, Cinthia Pinke e Nathalia Almeida, amizades que continuam. Aos colegas de UnB:A todos que contribuíram direta e/ou indiretamente na produção desse trabalho.iii Palavras-chave: remineralizador, substâncias húmicas, carga superficial, solubilidade, rochagem. iv ABSTRACT Brazil is one of the biggest world's producers and exporters. However, in general, Brazilian soils show small natural fertility, making necessary higher amounts in importation of fertilizers, which has direct impact in economy. In addition, soils located in tropical regions show a lower quantity of negative electric charge due to the mineralogy dominated by oxides and low participation of silicate clay minerals. The soil remineralization from the stonemeal practice has been pointed out by the capacity of increasing the electric charges density and providing vegetable nutrients. The stonemeal practice consists in incorporating rocks finely milled to the ground, but its low solubility limits the nutrient release, production mechanisms are needed which increase the solubility of these minerals. The application of humic substances promotes anatomical and biochemical changes on plants, especially expanding the organic acid production and the H + extrusion by the roots. The purposes of this study were: 1 -Determine whether the remineralizer addition (nepheline syenite) in a Latosoil typical of Cerrado changes the fertility indicators and the amount of electrical charges in a relatively short period. 2 -Evaluate whether the solution's applications containing humic substances alters the nutrient absorption capacity by corn plants (Zea mays L.). The remineralizer addition enhanced linearly the K + levels on the soil, after 60 and 105 application days. The rock was not capable of neutralizing the acidy indices, neither increasing the CEC (Cation-exchange capacity) effective;however, there was an increasing of 167% in the amount of permanent charges in the soil's sample that have received the equivalent to 2400kg ha −1 of the remineralizer. The plants treated with solutions that carry humic substances showed larger absorption of macronutrients. Still, the remineralizer's use resulted in Al 3+ and Na + lower absorptions in vegetable tissues.