| |
|
|
| Registros recuperados : 444 | |
| 121. |  | SANTOS, R. A. dos; BREMER NETO, H.; COELHO, R. D.; MONTEIRO, R. O. C. Análise econômica da implantação de sistemas de irrigação na citricultura do estado de São Paulo. Irriga, Botucatu, v. 11, n. 1, p. 66-77, jan./mar., 2006.| Biblioteca(s): Embrapa Mandioca e Fruticultura. |
|   |
| 122. | | ASSUNCAO, I. P.; ALFENAS, A. C.; COELHO, R. S. B.; LIMA, G. S. de A. Analise isoenzimatica de isolados de Colletotrichum gloeosporioides, agente etiologico da antracnose foliar da cebola. Summa Phytopathologica, Piracicaba, v.25, n.4, p.293-298, out./dez. 1999.| Biblioteca(s): Embrapa Hortaliças. |
| |
| 126. | | COELHO, R. de F. R.; ZARIN, D. J.; MIRANDA, I. S.; TUCKER, J. M. Análise florística e estrutural de uma floresta em diferentes estágios sucessionais no município de Castanhal, Pará. Acta Amazonica, Manaus, v. 33, n. 4, p. 563-582, out./dez. 2003.| Biblioteca(s): Embrapa Florestas. |
| |
| 132. | | TEIXEIRA, F. F.; VASCONCELLOS, J. H.; COELHO, R. S.; ARAÚJO, G. R. Banco Ativo de Germoplasma de milho: kit diversidade. Revista RG News, v. 4, n. 3, p. 198, 2018. Edição especial dos Anais do 5 Congresso Brasileiro de Recursos Genéticos, Fortaleza, nov. 2018.| Biblioteca(s): Embrapa Milho e Sorgo. |
|  |
| 140. | | COELHO, R. W.; MORAES, C. O. C.; GONÇALVES, J. O. N.; GIRARDI-DEIRO, A. M. Avaliação de gramíneas submetidas a pastejo. Bagé: EMBRAPA-UEPAE de Bagé, 1984. 6 p. (EMBRAPA-UEPAE de Bagé. Pesquisa em andamento, 1). Errata: relação correta de autores: Rogério Waltrick Coelho, Carlos Otávio Costa Moraes, José Otávio Neto Gonçalves, Auro Silva Acevedo, Ana Maria Girardi Deiro, Sérgio Silveira Gonzaga.| Biblioteca(s): Embrapa Meio-Norte; Embrapa Pecuária Sul; Embrapa Trigo. |
| |
| Registros recuperados : 444 | |
|
|
|
 | Acesso ao texto completo restrito à biblioteca da Embrapa Amazônia Oriental. Para informações adicionais entre em contato com cpatu.biblioteca@embrapa.br. |
Registro Completo
|
Biblioteca(s): |
Embrapa Amazônia Oriental. |
|
Data corrente: |
22/08/2006 |
|
Data da última atualização: |
28/11/2022 |
|
Tipo da produção científica: |
Artigo em Periódico Indexado |
|
Circulação/Nível: |
Internacional - A |
|
Autoria: |
SOMMER, R.; VLEK, P. L. G.; SÁ, T. D. de A.; VIELHAUER, K.; COELHO, R. de F. R.; FÖLSTER, H. |
|
Afiliação: |
TATIANA DEANE DE ABREU SA, CPATU. |
|
Título: |
Nutrient balance of shifting cultivation by burning or mulching in the eastern Amazon - evidence for subsoil nutrient accumulation. |
|
Ano de publicação: |
2004 |
|
Fonte/Imprenta: |
Nutrient Cycling in Agroecosystems, v. 68, n. 3, p. 257-271, Mar. 2004. |
|
DOI: |
10.1023/B:FRES.0000019470.93637.54 |
|
Idioma: |
Inglês |
|
Conteúdo: |
For over a hundred years shifting cultivation with slash-and-burn land preparation has been the predominant type of land use by smallholders in the Bragantina region of the Brazilian Eastern Amazon. This study contrasts the nutrient balance of slash-and-burn agriculture with a fire-free cultivation. Therefore, one half of a 3.5-year-old (28.7 t DM ha?1) and a 7-year-old woody fallow vegetation (46.5 t DM ha?1) was burnt and the other half mulched, leaving the biomass as a surface residue. Subsequently, a sequence of maize, beans and cassava was cropped for 1.5 year. Burning the 3.5- and 7-year-old fallow removed 97 and 94% of the C, 98 and 96% of the N, 90 and 63% of the P-stocks, and between 45 and 70% of the cations K, Mg and Ca of the aboveground biomass by volatilization or ash-particle transfer. These losses were avoided with the slash-and-mulch land preparation. Mulching did not increase the losses of nutrients by leaching, despite the high amount of rapidly decomposing surface mulch. Also the length of preceding fallow had no significant influence on leaching losses. At a depth of 3 m, leached nutrients were quantitatively negligible in both treatments. Comparing the nutrient fluxes at soil depths of 0.9 m, 1.8 m and 3 m, the amounts of all mobile nutrients, and also of chloride and sodium were markedly reduced during percolation and must have been retained. It is likely that nutrient retention in the subsoil layer is only temporary, emphasizing the need for a rapid re-establishment of the naturally deep-rooting secondary vegetation after abandonment of sites to enable uptake of these nutrients. The overall nutrient balance was highly negative for slash-and-burn. 291 and 403 kg N ha?1, 21 and 18 kg P ha?1, and 70 and 132 kg K ha?1 were removed from the burnt plots with a preceding fallow of 3.5 and 7 years, respectively. A reduced fallow period (3.5 years), which is a common trend in the region, resulted in a higher mean annual rate of nutrient loss averaged over the duration of the cycle than a fallow period of 7 years. Eliminating the burning losses by mulching brought the agricultural system back to an equilibrated or even slightly positive nutrient balance, even after a reduced fallow period. Thus, slash-and-mulch is a viable alternative to maintain agricultural productivity and ecosystem functioning. MenosFor over a hundred years shifting cultivation with slash-and-burn land preparation has been the predominant type of land use by smallholders in the Bragantina region of the Brazilian Eastern Amazon. This study contrasts the nutrient balance of slash-and-burn agriculture with a fire-free cultivation. Therefore, one half of a 3.5-year-old (28.7 t DM ha?1) and a 7-year-old woody fallow vegetation (46.5 t DM ha?1) was burnt and the other half mulched, leaving the biomass as a surface residue. Subsequently, a sequence of maize, beans and cassava was cropped for 1.5 year. Burning the 3.5- and 7-year-old fallow removed 97 and 94% of the C, 98 and 96% of the N, 90 and 63% of the P-stocks, and between 45 and 70% of the cations K, Mg and Ca of the aboveground biomass by volatilization or ash-particle transfer. These losses were avoided with the slash-and-mulch land preparation. Mulching did not increase the losses of nutrients by leaching, despite the high amount of rapidly decomposing surface mulch. Also the length of preceding fallow had no significant influence on leaching losses. At a depth of 3 m, leached nutrients were quantitatively negligible in both treatments. Comparing the nutrient fluxes at soil depths of 0.9 m, 1.8 m and 3 m, the amounts of all mobile nutrients, and also of chloride and sodium were markedly reduced during percolation and must have been retained. It is likely that nutrient retention in the subsoil layer is only temporary, emphasizing the need for a rapid r... Mostrar Tudo |
|
Palavras-Chave: |
Agricultura migratória; Brasil. |
|
Thesagro: |
Cobertura Morta; Queimada; Vegetação Secundária. |
|
Thesaurus NAL: |
Amazonia. |
|
Categoria do assunto: |
-- |
|
Marc: |
LEADER 03199naa a2200265 a 4500
001 1408538
005 2022-11-28
008 2004 bl uuuu u00u1 u #d
024 7 $a10.1023/B:FRES.0000019470.93637.54$2DOI
100 1 $aSOMMER, R.
245 $aNutrient balance of shifting cultivation by burning or mulching in the eastern Amazon - evidence for subsoil nutrient accumulation.$h[electronic resource]
260 $c2004
520 $aFor over a hundred years shifting cultivation with slash-and-burn land preparation has been the predominant type of land use by smallholders in the Bragantina region of the Brazilian Eastern Amazon. This study contrasts the nutrient balance of slash-and-burn agriculture with a fire-free cultivation. Therefore, one half of a 3.5-year-old (28.7 t DM ha?1) and a 7-year-old woody fallow vegetation (46.5 t DM ha?1) was burnt and the other half mulched, leaving the biomass as a surface residue. Subsequently, a sequence of maize, beans and cassava was cropped for 1.5 year. Burning the 3.5- and 7-year-old fallow removed 97 and 94% of the C, 98 and 96% of the N, 90 and 63% of the P-stocks, and between 45 and 70% of the cations K, Mg and Ca of the aboveground biomass by volatilization or ash-particle transfer. These losses were avoided with the slash-and-mulch land preparation. Mulching did not increase the losses of nutrients by leaching, despite the high amount of rapidly decomposing surface mulch. Also the length of preceding fallow had no significant influence on leaching losses. At a depth of 3 m, leached nutrients were quantitatively negligible in both treatments. Comparing the nutrient fluxes at soil depths of 0.9 m, 1.8 m and 3 m, the amounts of all mobile nutrients, and also of chloride and sodium were markedly reduced during percolation and must have been retained. It is likely that nutrient retention in the subsoil layer is only temporary, emphasizing the need for a rapid re-establishment of the naturally deep-rooting secondary vegetation after abandonment of sites to enable uptake of these nutrients. The overall nutrient balance was highly negative for slash-and-burn. 291 and 403 kg N ha?1, 21 and 18 kg P ha?1, and 70 and 132 kg K ha?1 were removed from the burnt plots with a preceding fallow of 3.5 and 7 years, respectively. A reduced fallow period (3.5 years), which is a common trend in the region, resulted in a higher mean annual rate of nutrient loss averaged over the duration of the cycle than a fallow period of 7 years. Eliminating the burning losses by mulching brought the agricultural system back to an equilibrated or even slightly positive nutrient balance, even after a reduced fallow period. Thus, slash-and-mulch is a viable alternative to maintain agricultural productivity and ecosystem functioning.
650 $aAmazonia
650 $aCobertura Morta
650 $aQueimada
650 $aVegetação Secundária
653 $aAgricultura migratória
653 $aBrasil
700 1 $aVLEK, P. L. G.
700 1 $aSÁ, T. D. de A.
700 1 $aVIELHAUER, K.
700 1 $aCOELHO, R. de F. R.
700 1 $aFÖLSTER, H.
773 $tNutrient Cycling in Agroecosystems$gv. 68, n. 3, p. 257-271, Mar. 2004.
Download
Esconder MarcMostrar Marc Completo |
|
Registro original: |
Embrapa Amazônia Oriental (CPATU) |
|
|
Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
Fechar
|
| Nenhum registro encontrado para a expressão de busca informada. |
|
|
