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| Valladares,Gustavo Souza; Camargo,Otávio Antônio de; Carvalho,José Ruy Porto de; Silva,Alessandra Maria Cia. |
| Agricultural management with chemicals may contaminate the soil with heavy metals. The objective of this study was to apply Principal Component Analysis and geoprocessing techniques to identify the origin of the metals Cu, Fe, Mn, Zn, Ni, Pb, Cr and Cd as potential contaminants of agricultural soils. The study was developed in an area of vineyard cultivation in the State of São Paulo, Brazil. Soil samples were collected and GPS located under different uses and coverings. The metal concentrations in the soils were determined using the DTPA method. The Cu and Zn content was considered high in most of the samples, and was larger in the areas cultivated with vineyards that had been under the application of fungicides for several decades. The concentrations of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PCA; GIS; Soil pollution; Copper; Zinc. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000300011 |
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| Vendrusculo,Laurimar Gonçalves; Magalhães,Paulo Sérgio Graziano; Vieira,Sidney Rosa; Carvalho,José Ruy Porto de. |
| Geostatistics identifies the spatial structure of variables representing several phenomena and its use is becoming more intense in agricultural activities. This paper describes a computer program, based on Windows Interfaces (Borland Delphi), which performs spatial analyses of datasets through geostatistic tools: Classical statistical calculations, average, cross- and directional semivariograms, simple kriging estimates and jackknifing calculations. A published dataset of soil Carbon and Nitrogen was used to validate the system. The system was useful for the geostatistical analysis process, for the manipulation of the computational routines in a MS-DOS environment. The Windows development approach allowed the user to model the semivariogram graphically... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Spatial variability; Semivariogram; Software. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000100017 |
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| Carvalho,José Ruy Porto de; Silveira,Pedro Marques da; Vieira,Sidney Rosa. |
| O objetivo deste trabalho foi estudar, mediante a geoestatística, a variabilidade espacial de pH, Ca, Mg, P e K em Latossolo Vermelho-Escuro distrófico, textura argilosa, cultivado durante cinco anos consecutivos (1992-1996), em três sistemas de preparo (arado, grade e plantio direto) na Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, em Santo Antônio de Goiás, GO. Das 30 combinações entre características químicas do solo, profundidades de coleta e sistemas de preparo, 14 apresentaram efeito pepita puro, indicando ausência de dependência espacial. Semivariogramas direcionais revelaram forte e moderada dependência espacial na direção de Y. Experimentos longevos com práticas culturais orientadas em uma única direção tendem a mudar a estrutura espacial... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: PH do solo; Preparo do solo; Sistema de cultivo; Métodos de análise. |
| Ano: 2002 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2002000800013 |
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