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 | Acesso ao texto completo restrito à biblioteca da Embrapa Amazônia Oriental. Para informações adicionais entre em contato com cpatu.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Amazônia Oriental. |
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Data corrente: |
01/11/2022 |
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Data da última atualização: |
01/11/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
ABRELL, T.; NAUDIN, K.; BIANCHI, F. J. J. A.; ARAGAO, D. V.; TITTONELL, P.; CORBEELS, M. |
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Afiliação: |
THOMAS ABRELL, CENTRE DE COOPÉRATION INTERNATIONALE EN RECHERCHE AGRONOMIQUE POUR LE DÉVELOPPEMENT; KRISHNA NAUDIN, CENTRE DE COOPÉRATION INTERNATIONALE EN RECHERCHE AGRONOMIQUE POUR LE DÉVELOPPEMENT; FELIX J. J. A. BIANCHI, WAGENINGEN UNIVERSITY AND RESEARCH; DEBORA VEIGA DE ARAGAO, CPATU; PABLO TITTONELL, CENTRE DE COOPÉRATION INTERNATIONALE EN RECHERCHE AGRONOMIQUE POUR LE DÉVELOPPEMENT; MARC CORBEELS, CENTRE DE COOPÉRATION INTERNATIONALE EN RECHERCHE AGRONOMIQUE POUR LE DÉVELOPPEMENT. |
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Título: |
Cassava root yield variability in shifting cultivation systems in the eastern Amazon region of Brazil |
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Ano de publicação: |
2022 |
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Fonte/Imprenta: |
Experimental Agriculture, v. 58, e38, p. 1-19, 2022. |
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DOI: |
https://doi.org/10.1017/S0014479722000333 |
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Idioma: |
Inglês |
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Conteúdo: |
Cassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha?1 (50% of the average yield of 14.2 Mg ha?1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha?1 . Cassava yield was associated with plant density at harvest (ranging from 0 to 10 000 plants ha? 1 ), suggesting that managing plant density is a key determinant of the attainable yield levels. In addition, differences in cassava root yields could be largely explained by differences in labour inputs for weeding and fallow clearing, the effect of the latter depending on soil texture. Therefore, our results suggest that labour is a key production factor for cassava in the shifting cultivation systems of the Eastern Amazon in which the use of external inputs, such as chemical fertilizers and herbicides, is limited. Further, root yields were influenced by the method of field preparation, whereby yields were about 50% lower (and more variable) when fields were prepared by slash-and-burn than by mechanical ploughing or herbicide application. Despite the significantly higher yields, these alternatives to burning the vegetation are, however, still hardly adopted in Paragominas. Hence, there is a need for supporting more sustainable production systems through local and national public policies. These new systems should not only focus on soil fertility management but also on weed control and, more generally, on labour productivity. MenosCassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha?1 (50% of the average yield of 14.2 Mg ha?1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha?1 . Cassava yield was a... Mostrar Tudo |
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Palavras-Chave: |
Weed pressure. |
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Thesagro: |
Erva Daninha; Fertilidade do Solo; Mandioca; Manihot Esculenta. |
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Thesaurus Nal: |
Cassava; Shifting cultivation; Soil fertility. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 03581naa a2200289 a 4500
001 2147936
005 2022-11-01
008 2022 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1017/S0014479722000333$2DOI
100 1 $aABRELL, T.
245 $aCassava root yield variability in shifting cultivation systems in the eastern Amazon region of Brazil$h[electronic resource]
260 $c2022
520 $aCassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha?1 (50% of the average yield of 14.2 Mg ha?1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha?1 . Cassava yield was associated with plant density at harvest (ranging from 0 to 10 000 plants ha? 1 ), suggesting that managing plant density is a key determinant of the attainable yield levels. In addition, differences in cassava root yields could be largely explained by differences in labour inputs for weeding and fallow clearing, the effect of the latter depending on soil texture. Therefore, our results suggest that labour is a key production factor for cassava in the shifting cultivation systems of the Eastern Amazon in which the use of external inputs, such as chemical fertilizers and herbicides, is limited. Further, root yields were influenced by the method of field preparation, whereby yields were about 50% lower (and more variable) when fields were prepared by slash-and-burn than by mechanical ploughing or herbicide application. Despite the significantly higher yields, these alternatives to burning the vegetation are, however, still hardly adopted in Paragominas. Hence, there is a need for supporting more sustainable production systems through local and national public policies. These new systems should not only focus on soil fertility management but also on weed control and, more generally, on labour productivity.
650 $aCassava
650 $aShifting cultivation
650 $aSoil fertility
650 $aErva Daninha
650 $aFertilidade do Solo
650 $aMandioca
650 $aManihot Esculenta
653 $aWeed pressure
700 1 $aNAUDIN, K.
700 1 $aBIANCHI, F. J. J. A.
700 1 $aARAGAO, D. V.
700 1 $aTITTONELL, P.
700 1 $aCORBEELS, M.
773 $tExperimental Agriculture$gv. 58, e38, p. 1-19, 2022.
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Registro original: |
Embrapa Amazônia Oriental (CPATU) |
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| Acesso ao texto completo restrito à biblioteca da Embrapa Instrumentação. Para informações adicionais entre em contato com cnpdia.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
27/11/2020 |
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Data da última atualização: |
16/08/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
LIMA, N. A.; MENDONÇA, G. C.; SILVA, G. T. S. T.; LIMA, B. S.; PARIS, E. C.; BERNARDI, M. I. B. |
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Afiliação: |
ELAINE CRISTINA PARIS, CNPDIA. |
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Título: |
Influence of the synthesis method on CuWO4 nanoparticles for photocatalytic application. |
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Ano de publicação: |
2021 |
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Fonte/Imprenta: |
Journal of Materials Science: Materials in Electronics, v. 32, n. 1, 2021. |
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Páginas: |
1139-1149 |
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ISSN: |
0957-4522 |
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DOI: |
https://doi.org/10.1007/s10854-020-04887-2 |
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Idioma: |
Inglês |
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Conteúdo: |
The textile industry is responsible for most of the consumption and inappropriate disposal of organic and highly toxic pollutants, such as dyes. Therefore, it is necessary to remediate polluting molecules before returning the water to the environment. Photocatalysis is a promising method for dye molecule degradation as it can provide complete mineralization through an efficient photocatalytic process. CuWO4 exhibits a band gap of 2.40 eV and can be excited with visible light, making it economically advantageous for industrial-scale applications. In this work, CuWO4 was synthesized by coprecipitation (CM), microwave-assisted hydrothermal (HM), and polymeric precursor (PPM) methods to evaluate the photocatalytic behavior in response to the different characteristics obtained from the synthesis routes. In photocatalytic measurements for OH· radical generation, the sacrificial agent H2O2 was used, and in order to delay the recombination process sodium oxalate and silver nitrate scavengers were applied under visible light. CuWO4 synthesized by PPM was more efficient in the dye degradation when the Ag+ scavenger was used, indicating that the predominant reaction mechanism was by direct oxidation or hydroxyl radicals. The surface charge (− 38.5 (PPM), − 29.7 (CM), and − 16.2 mV (HM)) influence was more relevant than the specific surface area (1 (PPM), 22 (CM), and 21 m2 g−1 (HM)) of the samples in the photocatalytic process. The complete degradation occurred in 80 min for the samples obtained by CM and HM and only 20 min were necessary for the sample synthesized by PPM. MenosThe textile industry is responsible for most of the consumption and inappropriate disposal of organic and highly toxic pollutants, such as dyes. Therefore, it is necessary to remediate polluting molecules before returning the water to the environment. Photocatalysis is a promising method for dye molecule degradation as it can provide complete mineralization through an efficient photocatalytic process. CuWO4 exhibits a band gap of 2.40 eV and can be excited with visible light, making it economically advantageous for industrial-scale applications. In this work, CuWO4 was synthesized by coprecipitation (CM), microwave-assisted hydrothermal (HM), and polymeric precursor (PPM) methods to evaluate the photocatalytic behavior in response to the different characteristics obtained from the synthesis routes. In photocatalytic measurements for OH· radical generation, the sacrificial agent H2O2 was used, and in order to delay the recombination process sodium oxalate and silver nitrate scavengers were applied under visible light. CuWO4 synthesized by PPM was more efficient in the dye degradation when the Ag+ scavenger was used, indicating that the predominant reaction mechanism was by direct oxidation or hydroxyl radicals. The surface charge (− 38.5 (PPM), − 29.7 (CM), and − 16.2 mV (HM)) influence was more relevant than the specific surface area (1 (PPM), 22 (CM), and 21 m2 g−1 (HM)) of the samples in the photocatalytic process. The complete degradation occurred in 80 min for the sample... Mostrar Tudo |
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Palavras-Chave: |
Oxic pollutants; Photocatalytic process. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02351naa a2200241 a 4500
001 2127141
005 2022-08-16
008 2021 bl uuuu u00u1 u #d
022 $a0957-4522
024 7 $ahttps://doi.org/10.1007/s10854-020-04887-2$2DOI
100 1 $aLIMA, N. A.
245 $aInfluence of the synthesis method on CuWO4 nanoparticles for photocatalytic application.$h[electronic resource]
260 $c2021
300 $a1139-1149
520 $aThe textile industry is responsible for most of the consumption and inappropriate disposal of organic and highly toxic pollutants, such as dyes. Therefore, it is necessary to remediate polluting molecules before returning the water to the environment. Photocatalysis is a promising method for dye molecule degradation as it can provide complete mineralization through an efficient photocatalytic process. CuWO4 exhibits a band gap of 2.40 eV and can be excited with visible light, making it economically advantageous for industrial-scale applications. In this work, CuWO4 was synthesized by coprecipitation (CM), microwave-assisted hydrothermal (HM), and polymeric precursor (PPM) methods to evaluate the photocatalytic behavior in response to the different characteristics obtained from the synthesis routes. In photocatalytic measurements for OH· radical generation, the sacrificial agent H2O2 was used, and in order to delay the recombination process sodium oxalate and silver nitrate scavengers were applied under visible light. CuWO4 synthesized by PPM was more efficient in the dye degradation when the Ag+ scavenger was used, indicating that the predominant reaction mechanism was by direct oxidation or hydroxyl radicals. The surface charge (− 38.5 (PPM), − 29.7 (CM), and − 16.2 mV (HM)) influence was more relevant than the specific surface area (1 (PPM), 22 (CM), and 21 m2 g−1 (HM)) of the samples in the photocatalytic process. The complete degradation occurred in 80 min for the samples obtained by CM and HM and only 20 min were necessary for the sample synthesized by PPM.
653 $aOxic pollutants
653 $aPhotocatalytic process
700 1 $aMENDONÇA, G. C.
700 1 $aSILVA, G. T. S. T.
700 1 $aLIMA, B. S.
700 1 $aPARIS, E. C.
700 1 $aBERNARDI, M. I. B.
773 $tJournal of Materials Science: Materials in Electronics$gv. 32, n. 1, 2021.
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Embrapa Instrumentação (CNPDIA) |
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