998 resultados para adubos verdes
Resumo:
Pós-graduação em Geografia - FCT
Resumo:
Pós-graduação em Geografia - FCT
Resumo:
Pós-graduação em Agronomia (Produção Vegetal) - FCAV
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Las actividades económicas generan diversos beneficios económicas y sociales pero, por desgracia, tienen también consecuencias negativas tanto en las mimas actividades económicas como en el bienestar de la población y el medio ambiente. Este conjunto de efectos negativos, desde la óptica de la literatura económica, se derivan de fallas de mercado que ocasiona estas externalidades negativas. Esto es, las actividades económicas generan efectos colaterales tales como emisiones o desechos que son depositados en el medio ambiente sin costo económico alguno y que generan impactos negativos.Las políticas públicas buscan reducir o eliminar estas externalidades negativas a través de la aplicación de diversas regulaciones o del uso de algún incentivo económico en donde destacan por su importancia el uso de diversos impuestos de corte ambiental. Estos impuestos ambientales tiene su fundamento teórico en el impuesto Pigou, que busca internalizar el costo de las externalidades negativas generadas por los agentes económicos.Este tipo de impuesto permite fundamentar la utilidad de aplicar impuestos verdes o ambientales para controlar o reducir las externalidades negativas y obtener incluso otros efectos positivos a través de los subsidios. Por desgracia, en América Latina es aún incipiente la aplicación de algunos de estos instrumentos fiscales. El principal objetivo de este documento es presentar la aplicación de este tipo de impuestos ambientales para automóviles y para botellas de plástico en Ecuador.
Resumo:
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.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Agronomia - FEIS