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| Leal,Fábio Tiraboschi; França,Ana Beatriz Coelho; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Marques Júnior,José; Scala Júnior,Newton La. |
| ABSTRACTSoil CO2 emissions (fCO2) in agricultural areas have been widely studied in global climate change research, but its characterization and quantification are restricted to small areas. Because spatial and time variability affect emissions, tools need to be developed to predict fCO2 for large areas. This study aimed to investigate soil magnetic susceptibility (MS) and its correlation with fCO2 in an agricultural environment. The experiment was carried out on a Typic Eutrudox located in Guariba-SP, Brazil. Results showed that there was negative spatial correlation between fCO2 and the magnetic susceptibility of Air Dried Soil (MSADS) up to 34.3 m distant. However, the fCO2 had no significant correlation with MSADS, magnetic susceptibility of sand... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Magnetism; Soil respiration; Spatial variability; Geostatistics. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000600535 |
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| Farhate,Camila Viana Vieira; Souza,Zigomar Menezes de; Oliveira,Stanley Robson de Medeiros; Carvalho,João Luís Nunes; Scala Júnior,Newton La; Santos,Ana Paula Guimarães. |
| ABSTRACT: The use of data mining is a promising alternative to predict soil respiration from correlated variables. Our objective was to build a model using variable selection and decision tree induction to predict different levels of soil respiration, taking into account physical, chemical and microbiological variables of soil as well as precipitation in renewal of sugarcane areas. The original dataset was composed of 19 variables (18 independent variables and one dependent (or response) variable). The variable-target refers to soil respiration as the target classification. Due to a large number of variables, a procedure for variable selection was conducted to remove those with low correlation with the variable-target. For that purpose, four approaches of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil CO2 emission; Data mining; Variable selection; Soil temperature; Soil organic matter. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000300216 |
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| Bahia,Angélica Santos Rabelo de Souza; Marques Júnior,José; Panosso,Alan Rodrigo; Camargo,Livia Arantes; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Scala Júnior,Newton La. |
| Soil CO2 emission (FCO2) is one of the main sources of carbon release into the atmosphere. Moreover, FCO2 is related to soil attributes governing the transfer of gases from soil to the atmosphere. This study aimed firstly to describe the spatial variability of hematite (Hm), goethite (Gt), iron extracted with sodium dithionite-citrate-bicarbonate (Fed) contents, soil CO2 emission (FCO2) and free-water porosity (FWP) and secondly, to develop statistical models to predict the above mentioned factors in an Oxisol cultivated under manual harvesting of sugarcane (Saccharumspp.) in southeastern Brazil. The study was conducted on an irregular 50 m × 50 m grid containing 89 points, each 0.5-10 m apart. The 0-0.1 m soil layer at each sampling point was used to... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hematite; Goethite; Soil respiration; Geostatistics; Cross-semivariograms. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162015000200157 |
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| Teixeira,Daniel De Bortoli; Bicalho,Elton da Silva; Panosso,Alan Rodrigo; Cerri,Carlos Eduardo Pellegrino; Pereira,Gener Tadeu; Scala Júnior,Newton La. |
| Soil CO2 emission (FCO2) is governed by the inherent properties of the soil, such as bulk density (BD). Mapping of FCO2 allows the evaluation and identification of areas with different accumulation potential of carbon. However, FCO2 mapping over larger areas is not feasible due to the period required for evaluation. This study aimed to assess the quality of FCO2 spatial estimates using values of BD as secondary information. FCO2 and BD were evaluated on a regular sampling grid of 60 m × 60 m comprising 141 points, which was established on a sugarcane area. Four scenarios were defined according to the proportion of the number of sampling points of FCO2 to those of BD. For these scenarios, 67 (F67), 87 (F87), 107 (F107) and 127 (F127) FCO2 sampling points... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Geostatistics; Cokriging; Ordinary kriging; Cross-variogram. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000300008 |
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