Vladimir Antonio Silva - Academia.edu (original) (raw)
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Papers by Vladimir Antonio Silva
Ciência e Agrotecnologia, 2013
Lands (broader concept than soils, including all elements of the environment: soils, geology, top... more Lands (broader concept than soils, including all elements of the environment: soils, geology, topography, climate, water resources, flora and fauna, and the effects of anthropogenic activities) of the state of Minas Gerais are in different soil, climate and socio-economics conditions and suitability for the production of agricultural goods is therefore distinct and mapping of agricultural suitability of the state lands is crucial for planning guided sustainability. Geoprocessing uses geographic information treatment techniques and GIS allows to evaluate geographic phenomena and their interrelationships using digital maps. To evaluate the agricultural suitability of state lands, we used soil maps, field knowledge, forest inventories and databases related to Ecological-Economic Zoning (EEZ) of Minas Gerais, to develop a map of land suitability in GIS. To do this, we have combined the maps of soil fertility, water stress, oxygen deficiency, vulnerability to erosion and impediments to m...
A mecanizacao e um importante recurso nos sistemas de producao agricola. O emprego correto de equ... more A mecanizacao e um importante recurso nos sistemas de producao agricola. O emprego correto de equipamentos e maquinas e de extrema importância para obtencao de altas produtividades agropecuarias, priorizando a racionalizacao dos custos e a conservacao do solo como recurso natural, tendo como meta a sustentabilidade. Sabe-se que utilizacao do solo sem o conhecimento basico das suas caracteristicas e necessidades pode resultar a degradacao desse importante recurso natural. Dessa forma, e de extrema importância o conhecimento da necessidade de potencia da maquina que cada solo exige, podendo-se dimensionar sua resistencia a mecanizacao agricola e relacionar esta resistencia com suas propriedades. Destaca-se que a resistencia a acao de implementos agricolas no solo tem total influencia do aumento da densidade aparente e da diminuicao da umidade, onde os maiores teores de agua e menores densidades aparentes resultam em menores valores da resistencia a penetracao (CUNHA; VIEIRA; MAGALHAES...
Research, Society and Development, 2020
This study has as main objective to identify the evolution of mental models on the knowledge of s... more This study has as main objective to identify the evolution of mental models on the knowledge of students of the Technical Course in Automotive Maintenance Integrated to High School, on the cooling systems of the internal combustion engines of the Otto and Diesel cycles. For such, a questionnaire was developed about the subject addressed. Five questions were prepared initially, that is, before the student had contact in the classroom with the subject addressed in this research. These questions were classified into three levels, which was easy, medium and difficult. After the content was administered, another questionnaire was applied containing five other questions, these were also classified into three levels of difficulty for the verification of the new scenario on the identification of students' mental models. The result of the first questionnaire was the finding that the students 'mental models are significantly heterogeneous and the use of the questionnaires before and a...
Revista Brasileira de Ciência do Solo, 2008
Kinetic studies on soil potassium release can contribute to a better understanding of K availabil... more Kinetic studies on soil potassium release can contribute to a better understanding of K availability to plants. This study was conducted to evaluate K release rates from the whole soil, clay, silt, and sand fractions of B-horizon samples of a basalt-derived Oxisol and a sienite-derived Ultisol, both representative soils from coffee regions of Minas Gerais State, Brazil. Potassium was extracted from each fraction after eight different shaking time periods (0-665 h) with either 0.001 mol L-1 citrate or oxalate at a 1:10 solid:solution ratio. First-order, Elovich, zero-order, and parabolic diffusion equations were used to parameterize the time dependence of K release. For the Oxisol, the first-order equation fitted best to the experimental data of K release, with similar rates for all fractions and independent of the presence of citrate or oxalate in the extractant solution. For all studied Ultisol fractions, in which K release rates increased when extractions were performed with citra...
A mecanizacao e de extrema importância na producao agricola. A utilizacao correta dos equipamento... more A mecanizacao e de extrema importância na producao agricola. A utilizacao correta dos equipamentos e maquinas tem total influencia no aumento da produtividade agropecuaria e na diminuicao dos custos. A utilizacao do solo sem o conhecimento das suas caracteristicas pode resultar em danos e degradacao desse recurso natural (CUNHA et al., 2009; RESENDE et al., 2014). O conhecimento da necessidade de potencia da maquina que cada solo requer, pode ser relacionado a sua resistencia a mecanizacao agricola, podendo-se comparar essa resistencia com as propriedades de cada solo. Objetivou-se neste trabalho comparar a resistencia a mecanizacao atraves da potencia exigida na barra de tracao do trator, em operacao de subsolagem, por dois diferentes solos representativos do Sudoeste de Minas Gerais, um latossolo e um cambissolo, de maneira a subsidiar a classificacao da aptidao agricola dessas terras quanto aos impedimentos a mecanizacao, tendo em vista a agricultura de precisao.
Ciência e Agrotecnologia, 2013
Lands (broader concept than soils, including all elements of the environment: soils, geology, top... more Lands (broader concept than soils, including all elements of the environment: soils, geology, topography, climate, water resources, flora and fauna, and the effects of anthropogenic activities) of the state of Minas Gerais are in different soil, climate and socio-economics conditions and suitability for the production of agricultural goods is therefore distinct and mapping of agricultural suitability of the state lands is crucial for planning guided sustainability. Geoprocessing uses geographic information treatment techniques and GIS allows to evaluate geographic phenomena and their interrelationships using digital maps. To evaluate the agricultural suitability of state lands, we used soil maps, field knowledge, forest inventories and databases related to Ecological-Economic Zoning (EEZ) of Minas Gerais, to develop a map of land suitability in GIS. To do this, we have combined the maps of soil fertility, water stress, oxygen deficiency, vulnerability to erosion and impediments to m...
A mecanizacao e um importante recurso nos sistemas de producao agricola. O emprego correto de equ... more A mecanizacao e um importante recurso nos sistemas de producao agricola. O emprego correto de equipamentos e maquinas e de extrema importância para obtencao de altas produtividades agropecuarias, priorizando a racionalizacao dos custos e a conservacao do solo como recurso natural, tendo como meta a sustentabilidade. Sabe-se que utilizacao do solo sem o conhecimento basico das suas caracteristicas e necessidades pode resultar a degradacao desse importante recurso natural. Dessa forma, e de extrema importância o conhecimento da necessidade de potencia da maquina que cada solo exige, podendo-se dimensionar sua resistencia a mecanizacao agricola e relacionar esta resistencia com suas propriedades. Destaca-se que a resistencia a acao de implementos agricolas no solo tem total influencia do aumento da densidade aparente e da diminuicao da umidade, onde os maiores teores de agua e menores densidades aparentes resultam em menores valores da resistencia a penetracao (CUNHA; VIEIRA; MAGALHAES...
Research, Society and Development, 2020
This study has as main objective to identify the evolution of mental models on the knowledge of s... more This study has as main objective to identify the evolution of mental models on the knowledge of students of the Technical Course in Automotive Maintenance Integrated to High School, on the cooling systems of the internal combustion engines of the Otto and Diesel cycles. For such, a questionnaire was developed about the subject addressed. Five questions were prepared initially, that is, before the student had contact in the classroom with the subject addressed in this research. These questions were classified into three levels, which was easy, medium and difficult. After the content was administered, another questionnaire was applied containing five other questions, these were also classified into three levels of difficulty for the verification of the new scenario on the identification of students' mental models. The result of the first questionnaire was the finding that the students 'mental models are significantly heterogeneous and the use of the questionnaires before and a...
Revista Brasileira de Ciência do Solo, 2008
Kinetic studies on soil potassium release can contribute to a better understanding of K availabil... more Kinetic studies on soil potassium release can contribute to a better understanding of K availability to plants. This study was conducted to evaluate K release rates from the whole soil, clay, silt, and sand fractions of B-horizon samples of a basalt-derived Oxisol and a sienite-derived Ultisol, both representative soils from coffee regions of Minas Gerais State, Brazil. Potassium was extracted from each fraction after eight different shaking time periods (0-665 h) with either 0.001 mol L-1 citrate or oxalate at a 1:10 solid:solution ratio. First-order, Elovich, zero-order, and parabolic diffusion equations were used to parameterize the time dependence of K release. For the Oxisol, the first-order equation fitted best to the experimental data of K release, with similar rates for all fractions and independent of the presence of citrate or oxalate in the extractant solution. For all studied Ultisol fractions, in which K release rates increased when extractions were performed with citra...
A mecanizacao e de extrema importância na producao agricola. A utilizacao correta dos equipamento... more A mecanizacao e de extrema importância na producao agricola. A utilizacao correta dos equipamentos e maquinas tem total influencia no aumento da produtividade agropecuaria e na diminuicao dos custos. A utilizacao do solo sem o conhecimento das suas caracteristicas pode resultar em danos e degradacao desse recurso natural (CUNHA et al., 2009; RESENDE et al., 2014). O conhecimento da necessidade de potencia da maquina que cada solo requer, pode ser relacionado a sua resistencia a mecanizacao agricola, podendo-se comparar essa resistencia com as propriedades de cada solo. Objetivou-se neste trabalho comparar a resistencia a mecanizacao atraves da potencia exigida na barra de tracao do trator, em operacao de subsolagem, por dois diferentes solos representativos do Sudoeste de Minas Gerais, um latossolo e um cambissolo, de maneira a subsidiar a classificacao da aptidao agricola dessas terras quanto aos impedimentos a mecanizacao, tendo em vista a agricultura de precisao.