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Your search keyword '"Rebellato, Lilian"' showing total 2 results
Start Over Author "Rebellato, Lilian" Topic soil classification
2 results on '"Rebellato, Lilian"'

1. Sensor mapping of Amazonian Dark Earths in deforested croplands

Author

Söderström, Mats, Eriksson, Jan, Isendahl, Christian, Schaan, Denise Pahl, Stenborg, Per, Rebellato, Lilian, and Piikki, Kristin

Subjects
Remote Sensing, Electromagnetic induction, Archaeology, Soil classification, Terra preta, MARSplines, Soil Science, Remote sensing, Portable x-ray fluorescence
Abstract

Amazonian Dark Earths (ADEs) are fertile soils for agricultural production as well as important archaeological resources for understanding the pre-Columbian past of the Neotropical lowland rainforest. ADEs are threatened by expanding land exploitation and there is a need to develop efficient approaches to soil mapping and analysis for documenting these soils. In this paper we assess the potential of satellite remote sensing and proximal soil sensing to map, predict and monitor ADEs in land affected by agro-industrial development. We use instruments based on portable x-ray fluorescence (PXRF) and electromagnetic induction (EMI) as well as high-resolution satellite data (Spot 6) for detailed soil surveys at a 10-ha ADE site now mainly used for soybean production on the Belterra Plateau, Pará, Brazil. We predict the regional occurrence of ADE in a c. 250km2 test area centred on the known ADE site São Francisco using satellite data. Multivariate adaptive regression splines models were parameterised for predictions of soil organic carbon (SOC), cation exchange capacity (CEC), phosphorus (P) and depth of the A horizon in ADEs from sensor data – both from individual sensors and in sensor combinations. Combining sensors gave the best validation results: the highest modelling efficiencies (E) were 0.70 (SOC), 0.88 (CEC) and 0.74 (for both P and A depth). The most powerful single proximal sensor outputs in the predictions were Sr from the PXRF data and magnetic susceptibility (MSa) as measured by the EMI instrument. In the regional satellite based model we located 17 previously unrecorded ADE sites >2ha. Ground control checks showed that 10 out of 11 sites were correctly classified. We conclude that these sensors are useful in studies of ADE in deforested cropland and provide new opportunities for detailed studies of the archaeological record.

Published
2016
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2. Micronutrient availability in amazonian dark earths and adjacent soils.

Author

Sátiro, José Nivaldo de Oliveira, Motta, Antônio Carlos V., Demetrio, Wilian C., Segalla, Rodrigo F., Cremonesi, Marcus Vinicius, Araújo, Eloá Moura, Falcão, Newton Paulo de Souza, Martins, Gilvan C., Muniz, Aleksander W., Taube, Paulo Sérgio, Rebellato, Lilian, de Oliveira Júnior, Raimundo C., Teixeira, Wenceslau G., Neves, Eduardo G., Lima, Helena P., Shock, Myrtle P., Kille, Peter, Cunha, Luís, TPI Network, and Brown, George G.

Subjects
*SOILS, *SOIL depth, *SOIL management, *SOIL classification, *PLANT nutrients
Abstract

[Display omitted] • A meta-analysis of extractable micronutrients in Amazonian Dark Earths was performed. • Micronutrient contents were compared at 20 sites with ADEs and adjacent soils. • Ni, Cu, Zn, Mn and Fe were studied at depth in 9 sites with forest and agriculture. • Zn, Mn and Cu contents were higher in ADEs and Fe was higher in adjacent soils. • Modern agriculture at some sites had lower contents of extractable Fe or Mn. Amazonian Dark Earths (ADEs) are highly fertile soils in areas with predominance of unfertile soils. However, the variation in nutrient availability between regions and the resilience of ADEs to modern agricultural use is still little known, particularly regarding micronutrient contents. Hence, the present study synthesized current information of ADE impacts on extractable micronutrient (Cu, Ni, Fe, Mn, Zn, B) contents at different soil depths and assessed in detail the role of both soil depth and land-use type on extractable Cu, Ni, Fe, Mn and Zn in nine ADEs and adjacent (ADJ) soils from different Amazonian regions. The land-use systems chosen were secondary old (OF) or young (YF) forests, and agricultural systems (AS) in Iranduba, Belterra and Porto Velho. Only eight studies compared extractable (Mehlich-1) micronutrient contents at 21 sites with ADEs and ADJ soils, but only four studies included depths greater than 30 cm, and B and Ni were evaluated in only one study. Higher Mn and Zn, but lower Fe contents were found in ADEs both from literature data and in the present study, especially in the first 30 cm depth. Increases in extractable Ni and Cu in ADEs varied according to the site and the land use considered. Micronutrient contents tended to decrease with depth, but varied depending on the element, site, soil type and land use. Sites with modern agriculture showed few differences in extractable micronutrient contents, except for a decrease in Fe in Belterra and Mn in Porto Velho. Considering the high amounts of some micro- and macronutrients in ADEs further work is warranted concerning soil management and nutrient balance in plants grown on these soils. [ABSTRACT FROM AUTHOR]

Published
2021
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