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| Abreu,Cleide Aparecida de; van Raij,Bernardo; Abreu,Mônica Ferreira de; González,Antonio Paz. |
| Microelements are an important issue in agriculture, due to their need as micronutrients for plants and also to the possibility of the build-up of toxic levels for plants and animals. Five micronutrients (B, Cu, Fe, Mn, and Zn) are routinely determined in soil analysis for advisory purposes. Other four elements (Cd, Cr, Pb, and Ni) are considered environmentally important heavy metals in farmland soils. Thus high contents of these metals in cropland might go eventually unnoticed. In this paper we present an approach that can be used to monitor the contents of the nine elements in farmland soils using advisory soil testing. A total of 13,416 soil samples from 21 Brazilian states, 58% of them from the state of São Paulo, sent by farmers were analyzed. Boron... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil analyses; Micronutrients; Heavy metals; Deficiency; Toxicity; Interpretation limits. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000600009 |
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| Ribeiro,Bruno Teixeira; Silva,Sérgio Henrique Godinho; Silva,Elen Alvarenga; Guilherme,Luiz Roberto Guimarães. |
| ABSTRACT The X-ray fluorescence (XRF) is an analytical technique for determination of elemental composition of different materials. In soils, the XRF has many pedological, environmental and agronomic applications, mainly after the emergence of portable equipments (pXRF). This technique has been recently adopted and successfully used for soil characterization worldwide, but very rare works have been carried out in soils of developing countries. The soil characterization includes the complete elemental composition determination (nutrients, trace and rare-earth elements) and allows estimating some soil physical and chemical properties. In Brazil, this technique is still incipient, mainly the use of pXRF, however, it can greatly contribute to soil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil analyses; Soil morphometrics; Soil characterization. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000300245 |
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| Silva,Sérgio Henrique Godinho; Teixeira,Anita Fernanda dos Santos; Menezes,Michele Duarte de; Guilherme,Luiz Roberto Guimarães; Moreira,Fatima Maria de Souza; Curi,Nilton. |
| ABSTRACT Determination of soil properties helps in the correct management of soil fertility. The portable X-ray fluorescence spectrometer (pXRF) has been recently adopted to determine total chemical element contents in soils, allowing soil property inferences. However, these studies are still scarce in Brazil and other countries. The objectives of this work were to predict soil properties using pXRF data, comparing stepwise multiple linear regression (SMLR) and random forest (RF) methods, as well as mapping and validating soil properties. 120 soil samples were collected at three depths and submitted to laboratory analyses. pXRF was used in the samples and total element contents were determined. From pXRF data, SMLR and RF were used to predict soil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil analyses; Spatial prediction; Proximal sensor.. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542017000600648 |
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