Maria Tavares - Academia.edu (original) (raw)
Papers by Maria Tavares
Semina: Ciências Agrárias, 2014
Swine effluent has been applied to soils to promote nutrient cycling and reduce the uncontrolled ... more Swine effluent has been applied to soils to promote nutrient cycling and reduce the uncontrolled disposal of effluents into bodies of water. However, the use of these effluents on various crops has raised environmental and public health concerns. Oilseed radish crop (Raphanus sativus L.) is a winter crop planted in no-tillage systems as a green fertilizer that also can be used for biodiesel, and it requires high levels of nutrients for its development. Thus, the present study aimed to evaluate the environmental and agronomic effects of the application of swine wastewater on oilseed radish. The experiment was conducted in a 0.162 ha area with the following treatments: unirrigated (rainfed), irrigated, and fertilized with swine wastewater (370 m 3 ha-1 cycle-1). After each rainfall event, analyses were conducted for the main macro and micronutrients in the runoff and percolated material from drainage lysimeters. Changes in the physical and chemical characteristics of the soil were also analyzed, as were the agronomic and nutritional indices of the dry crop phytomass in full blooming stage. Application of swine wastewater at a level of 370 m 3 ha-1 produces a crop with better agronomic quality. Over the long term, however, caution should be taken regarding the surface runoff of NO 3-, P, K, Mn and total salts and the percolation of NO 3-, Na and Cu. Moreover, the rainfall occurred one day after fertigation contributed to the increase of the levels of P, K, Na, Cu, Zn and Mn in the percolated material.
Bragantia, 2010
O presente trabalho teve-se como objetivo diagnosticar o uso atual das terras e suas implicações ... more O presente trabalho teve-se como objetivo diagnosticar o uso atual das terras e suas implicações na variabilidade espacial dos atributos físicos densidade do solo (Ds), matéria orgânica (MO), frações texturais (areia, silte e argila) e argila dispersa em água (ADA), na bacia hidrográfica do Ribeirão Marcela, Região Alto Rio Grande, MG, através de técnicas de geoestatística, com a finalidade de observar padrões de ocorrência desses atributos na paisagem. Coletaram-se amostras de solo na camada de 0 a 0,15 m em malha, com intervalos regulares de 240 x 240 m (macroescala) e de 60 x 60 m (microescala), totalizando 165 pontos. A Ds apresentou-se com valores na faixa de 1,05 a 1,15 g cm -3 acima, portando, do valor característico para Latossolos (0,95 g cm -3 ), enquanto os maiores valores foram obtidos nas glebas sob pastejo. Os valores de MO variaram de 1,5 a 4,5 dag kg -1 , detectando-se maiores concentrações nas glebas sob eucalipto, cerrado mais denso e várzeas. As frações texturais variaram seguindo a rede de drenagem e a ADA indicou valores baixos ao longo de toda a bacia. Os mapas de krigagem mostraram-se importante no estudo e compreensão da variabilidade espacial de atributos físicos do solo na bacia hidrográfica, indicando áreas críticas de manejo.
Semina: Ciências Agrárias, 2014
Swine effluent has been applied to soils to promote nutrient cycling and reduce the uncontrolled ... more Swine effluent has been applied to soils to promote nutrient cycling and reduce the uncontrolled disposal of effluents into bodies of water. However, the use of these effluents on various crops has raised environmental and public health concerns. Oilseed radish crop (Raphanus sativus L.) is a winter crop planted in no-tillage systems as a green fertilizer that also can be used for biodiesel, and it requires high levels of nutrients for its development. Thus, the present study aimed to evaluate the environmental and agronomic effects of the application of swine wastewater on oilseed radish. The experiment was conducted in a 0.162 ha area with the following treatments: unirrigated (rainfed), irrigated, and fertilized with swine wastewater (370 m 3 ha-1 cycle-1). After each rainfall event, analyses were conducted for the main macro and micronutrients in the runoff and percolated material from drainage lysimeters. Changes in the physical and chemical characteristics of the soil were also analyzed, as were the agronomic and nutritional indices of the dry crop phytomass in full blooming stage. Application of swine wastewater at a level of 370 m 3 ha-1 produces a crop with better agronomic quality. Over the long term, however, caution should be taken regarding the surface runoff of NO 3-, P, K, Mn and total salts and the percolation of NO 3-, Na and Cu. Moreover, the rainfall occurred one day after fertigation contributed to the increase of the levels of P, K, Na, Cu, Zn and Mn in the percolated material.
Bragantia, 2010
O presente trabalho teve-se como objetivo diagnosticar o uso atual das terras e suas implicações ... more O presente trabalho teve-se como objetivo diagnosticar o uso atual das terras e suas implicações na variabilidade espacial dos atributos físicos densidade do solo (Ds), matéria orgânica (MO), frações texturais (areia, silte e argila) e argila dispersa em água (ADA), na bacia hidrográfica do Ribeirão Marcela, Região Alto Rio Grande, MG, através de técnicas de geoestatística, com a finalidade de observar padrões de ocorrência desses atributos na paisagem. Coletaram-se amostras de solo na camada de 0 a 0,15 m em malha, com intervalos regulares de 240 x 240 m (macroescala) e de 60 x 60 m (microescala), totalizando 165 pontos. A Ds apresentou-se com valores na faixa de 1,05 a 1,15 g cm -3 acima, portando, do valor característico para Latossolos (0,95 g cm -3 ), enquanto os maiores valores foram obtidos nas glebas sob pastejo. Os valores de MO variaram de 1,5 a 4,5 dag kg -1 , detectando-se maiores concentrações nas glebas sob eucalipto, cerrado mais denso e várzeas. As frações texturais variaram seguindo a rede de drenagem e a ADA indicou valores baixos ao longo de toda a bacia. Os mapas de krigagem mostraram-se importante no estudo e compreensão da variabilidade espacial de atributos físicos do solo na bacia hidrográfica, indicando áreas críticas de manejo.