Eficiência agronômica de fertilizantes organominerais sólidos e fluidos em relação à disponibilidade de fósforo

Pós-graduação em Agronomia (Agricultura) - FCA

Avaliação do potencial de uso agrícola da fluorita com óxido silício (AgroSiCa), derivado da fabricação de fertilizantes fosfatados

Phosphate fertilizers are critical for crop production in tropical soils, which are known for having high phosphate-fixing capacity and aluminium saturation, as well as low pH and calcium contents. Fluorine is a component of many phosphate rocks used to make phosphate fertilizers, via a process that generates hexafluorosilicic acid (H2SiF6). While many treatment technologies have been proposed for removal of fluorine in industrial facilities, little attention has been given to a process of neutralizing H2SiF6 with calcium oxide aiming to find out an alternative and sustainable use of a by-product with a great potential for beneficial use in tropical agriculture. This study evaluated the effect of a by-product of phosphoric acid production (fluorite with silicon oxide, hereafter called AgroSiCa) in levels of phosphorus (P), calcium (Ca), silicon (Si), aluminum (Al) and fluorine (F) and some others parameters in soils as on growth of soybean and corn. Experiments were conducted in a greenhouse condition at the Federal University of Lavras (UFLA), Lavras, Minas Gerais, using different types of soils in tropical regions and different doses of AgroSiCa. The application of AgroSiCa resulted in a slight increase in soil pH and significant increases in calcium, phosphorus and silicon in the soil solution and the shoots of corn and soybeans. We also found very low levels of fluoride in all soil leachates. A significant reduction of labile aluminum levels found in all soils after the cultivation of corn and soybeans. In sum, AgroSiCa improved soil properties and contributed to better growth of both cultures. In sum, AgroSiCa improved soil properties and contributed to a better growth of both crops. Our results show that reacting H2SiF6 derived from the wet-process phosphoric acid production with calcium oxide leads to a by-product with potential for agricultural use, especially when applied in highly-weathered soils. Besides providing calcium and silicon to plants, the use of such by-product in soils with high phosphate-fixing capacity and high aluminium saturation delivers additional benefits, since fluoride and silicon can play an important role in improving soil conditions due to the formation of less plant-toxic forms of aluminium, as well as upon decreasing phosphate fixation, thus improving root development and making fertilizer-derived phosphate more available for plant growth.

Níquel em solo e plantas de milho cultivadas em área tratada com lodo de esgoto durante 15 anos consecutivos

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Características agronômicas de milho adubado com fertilizantes organominerais a base de cama de frango e fosfatos.

2016

Diagnose da composição nutricional e eficiência de fertilizantes nitrogenados na cultura do milho

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Comportamento de milho (Zea Mays L.) e propriedades físicas do solo, no sistema plantio direto, em resposta a aplicação de fertilizante organomineral

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Doses, épocas e modos de aplicação da uréia comum e revestida na cultura do milho

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Aplicação de fertilizantes foliares em culturas anuais

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Elementos-traço As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn em latossolos e plantas de milho após treze aplicações anuais de lodo de esgoto

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Uso de biofertilizante na produtividade do milho

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Eficiência agronômica de rejeitos da indústria de fertilizantes fosfatados

Pós-graduação em Agronomia (Horticultura) - FCA

Análise das emissões de gases do efeito estufa na produção do milho através da fertilização por resíduos de biocombustível. Estudo de caso : Dedelow - Brandemburgo - Alemanha

The focus of this research study were gas exchange between soil and atmosphere of nitrous oxide (N2O) between different fertilization treatments Corn The research, conducted in the experimental field Dedelow - Brandenburg / Germany, analyzed three different fertilization treatments, aiming to quantify GHE emissions, to identify the influence of the residue of biogas in the release of these gases process in agricultural soils in search for a solution fertilization less harmful to the environment and the greenhouse effect , based on the comparison of three treatments: organic fertilization, mineral fertilization and no fertilization. It was found through the analysis of the measurements that the first was the one which issued N2O, showing that even though coming from the residue of biogas , when returned to the soil, it becomes harmful to the environment and global warming . The cultivation of energy crops can lower or raise the emissions of greenhouse gases, so it is necessary for further research on this question not only in Germany , where such research is in continuity, but also in Brazil, a pioneer in the introduction to his energy matrix of a biofuel produced from cane sugar

Adubação de sistemas: antecipação de adubação nitrogenada para a cultura do milho em integração lavoura-pecuária

Traditionally in no-tillage systems, fertilization is done to the catch crop. In general nutrient cycling in crop systems has not been treated as an important tool in the process of nutrient supplying for plants. The type and the condition in which vegetable residuesis decomposed can affect the efficiency of nutrient cycling.This study assessed the effect of anticipated nitrogen fertilization in crop-livestock systems on cultivated cornproduction, rate ofnutrient release from plant residue, and theN-minerallevels of soil. The study was carried out in the city Abelardo Luz (SC) in a Clayey Oxisol. The experimental design was a randomized block design with three replications. The treatments were arranged in a 2 x 2 factorial arrangement. The first factor was N Fertilization Time: in the N-Pasture level, nitrogen (200 kg ha-1 N) and N-Grains level, no nitrogen was applied. The second factor was the Grazing Height, characterized by two sward heights of oat at 15 cm (Low Height Pasture) and at 30 cm (High Height Pasture). Corn hybrid ‘Máximus’ was sowed in 10thOctober, 31 days after the removal of animals. In the twelve resulting plots from the combination of treatments on pasture phase (N Fertilization Time x Grazing Height) rates of N-fertilizer (0, 100, 200 e 300 Kg ha-1 of N) as urea were allocated in the split plot.We conclude that anticipated N fertilization of winter cover crop pasture to provide high-quality forage and carry-over N to the subsequent corn crop and may eventually replace side drees nitrogen fertilization on corn and can improve overall N fertilizer efficiency use in integrated crop-livestock systems.The rate of K release from plant residues is very fast, releasing large quantities in the first days after plant desiccation.Despite of considerably high nitrogen dose used in both the pasture and at the grain crop it was not observed nitrate leaching risks during the study period.

Fontes de financiamento do processo de expansão das empresas de fertilizantes nas regiões centro e sul do Brasil : 1978/1985

Este estudo realiza, através do setor de fertilizantes no Brasil, algumas discussões em torno das fontes de fundos utilizadas pelas empresas no financiamento dos investimentos ativos. Verifica as formas de relacionamento da empresa capitalista moderna com os mercados financeiros e acionário e a capacidade de formação de recursos próprios pela mesma. Aborda a evolução do setor de fertilizantes no Brasil, esclarecendo sua ligação com o setor agrícola nacional e as implicações que as medidas governamentais de política agrícola provocam no setor de insumos modernos. Faz uma revisão crítica da literatura, expondo o pensamento de vários autores sobre o financiamento do processo de crescimento e valorização da empresa capitalista moderna

Fertilizantes : atividade agrícola, aspectos gerais da indústria e estudo da demanda

A dissertação nos expõe um histórico do desenvolvimento da agricultura, e de fertilizantes desde seus primórdios. Apresenta os principais fatores econômicos, políticos e sociais que afetam a agricultura, e por conseguinte o consumo de fertilizantes, e seu comportamento no passado recente. Discorre sobre o que são fertilizantes, seu processo de obtenção, e seu consumo em períodos recentes. Situa o setor de fertilizantes, dentro de um composto de Marketing atualmente praticado, pelas empresas no Brasil. Projeta, a demanda de fertilizantes do Brasil para os próximos 10 anos, com base em variáveis externas e internas ao setor, e também adaptando-se curvas aos valores históricos de consumo