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Registro Completo |
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
18/05/1994 |
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Data da última atualização: |
18/05/1994 |
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Autoria: |
NOGUEIRA, A. C.; KUNIYOSHI, Y. S.; SOARES, R. V. |
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Título: |
Zonas de vida para o estado de Santa Catarina segundo a classificacao das formacoes vegetais de Holdridge |
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Ano de publicação: |
1987 |
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Fonte/Imprenta: |
Floresta, Curitiba, v.17, n.1/2, p.103-112, 1987 |
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ISSN: |
0015-3826 |
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Idioma: |
Português |
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Palavras-Chave: |
Life zones; Santa Catarina; Zonas de vida. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 00539naa a2200181 a 4500
001 1283399
005 1994-05-18
008 1987 bl uuuu u00u1 u #d
022 $a0015-3826
100 1 $aNOGUEIRA, A. C.
245 $aZonas de vida para o estado de Santa Catarina segundo a classificacao das formacoes vegetais de Holdridge
260 $c1987
653 $aLife zones
653 $aSanta Catarina
653 $aZonas de vida
700 1 $aKUNIYOSHI, Y. S.
700 1 $aSOARES, R. V.
773 $tFloresta, Curitiba$gv.17, n.1/2, p.103-112, 1987
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Registro original: |
Embrapa Florestas (CNPF) |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Agrobiologia. Para informações adicionais entre em contato com cnpab.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Agrobiologia. |
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Data corrente: |
19/04/2000 |
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Data da última atualização: |
19/04/2000 |
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Autoria: |
ALVES, B. J. R.; RESENDE, A. S.; URQUIAGA, S.; BODDEY, R. M. |
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Título: |
Biological nitrogen fixation by two tropical forage legumes assessed from the relative ureide abundance of stem solutes: 15N calibration of the technique in sand culture. |
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Ano de publicação: |
2000 |
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Fonte/Imprenta: |
Nutrient Cycling in Agroecosystems, Netherlands, v. 56, p. 165-176, 2000. |
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Idioma: |
Inglês |
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Conteúdo: |
The use of the relative ureide abundance (RUA) in the sap of mainly tropical ureide-producing legumes as a means to estimate the contribution of biological nitrogen fixation (BNF) is potentially an useful technique as it does not require the use of reference plants or additions of 15N-labelled fertilizer, and the analyses necessitate only relatively dimplr equipment. However, one problem in the application of the technique arises from the difficulty of obtaining sap samples from such legumes, especially small-stemmed forage legumes under field conditions. This study was conducted to investigate the possibility of using RUA in hot-water extracts of the stems of two forage legumes, Desmodium ovalifolium and a Centrosema hybrid, to estimate the contribution of BNF. In this case only ureide and nitrate are analysed to calculate RUA (100 x ureide-N/(ureide-N + nitrate-N)). The technique was calibrated with the 15N isotope dilution technique in sand culture where the plants were fed with 5 different levels of nitrate (0, 12.5, 25, 50 and 100 mg N pot-1). Despite the fact that in many stem extracts more than 90% of the N was neither nitrate or ureide, the colorimetric techniques utilised proved reliable and relatively immune to interference from other solutes in the extracts. One problem with the use of the 15N dilution technique to calibrate the RUA technique is that the former gives an integrated estimate of the BNF contribution since planting (or between harvests) and the latter is a point estimate at the time of sampling. This was overcome by using a 'plant to plant simulation technique' where estimates of BNF are calculated from the daily accumulation of total N and the labelled N derived from the growth medium by the legumes using a curve-fitting strategy. These estimates of BNF for the days when stem extracts were analysed for nitrate and ureide showed linear correlations (r2 = 0.82 and 0.90 for the D. ovalifolium and Centrosema hybrid, respectively). This indicated that RUA of stem extracts of these two legumes was a reliable indicator of the BNF contribution, at least under controlled conditions. MenosThe use of the relative ureide abundance (RUA) in the sap of mainly tropical ureide-producing legumes as a means to estimate the contribution of biological nitrogen fixation (BNF) is potentially an useful technique as it does not require the use of reference plants or additions of 15N-labelled fertilizer, and the analyses necessitate only relatively dimplr equipment. However, one problem in the application of the technique arises from the difficulty of obtaining sap samples from such legumes, especially small-stemmed forage legumes under field conditions. This study was conducted to investigate the possibility of using RUA in hot-water extracts of the stems of two forage legumes, Desmodium ovalifolium and a Centrosema hybrid, to estimate the contribution of BNF. In this case only ureide and nitrate are analysed to calculate RUA (100 x ureide-N/(ureide-N + nitrate-N)). The technique was calibrated with the 15N isotope dilution technique in sand culture where the plants were fed with 5 different levels of nitrate (0, 12.5, 25, 50 and 100 mg N pot-1). Despite the fact that in many stem extracts more than 90% of the N was neither nitrate or ureide, the colorimetric techniques utilised proved reliable and relatively immune to interference from other solutes in the extracts. One problem with the use of the 15N dilution technique to calibrate the RUA technique is that the former gives an integrated estimate of the BNF contribution since planting (or between harvests) and the latter... Mostrar Tudo |
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Palavras-Chave: |
BNF; FBN; Fixacao biologica de nitrogenio; Nitrogen fixing bacteria; Tropical zones. |
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Thesagro: |
Centrosema; Diluição Isotópica; Leguminosa Forrageira; Leguminosa Tropical. |
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Thesaurus NAL: |
legumes; tracer techniques. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 03051naa a2200289 a 4500
001 1621145
005 2000-04-19
008 2000 bl --- 0-- u #d
100 1 $aALVES, B. J. R.
245 $aBiological nitrogen fixation by two tropical forage legumes assessed from the relative ureide abundance of stem solutes$b15N calibration of the technique in sand culture.
260 $c2000
520 $aThe use of the relative ureide abundance (RUA) in the sap of mainly tropical ureide-producing legumes as a means to estimate the contribution of biological nitrogen fixation (BNF) is potentially an useful technique as it does not require the use of reference plants or additions of 15N-labelled fertilizer, and the analyses necessitate only relatively dimplr equipment. However, one problem in the application of the technique arises from the difficulty of obtaining sap samples from such legumes, especially small-stemmed forage legumes under field conditions. This study was conducted to investigate the possibility of using RUA in hot-water extracts of the stems of two forage legumes, Desmodium ovalifolium and a Centrosema hybrid, to estimate the contribution of BNF. In this case only ureide and nitrate are analysed to calculate RUA (100 x ureide-N/(ureide-N + nitrate-N)). The technique was calibrated with the 15N isotope dilution technique in sand culture where the plants were fed with 5 different levels of nitrate (0, 12.5, 25, 50 and 100 mg N pot-1). Despite the fact that in many stem extracts more than 90% of the N was neither nitrate or ureide, the colorimetric techniques utilised proved reliable and relatively immune to interference from other solutes in the extracts. One problem with the use of the 15N dilution technique to calibrate the RUA technique is that the former gives an integrated estimate of the BNF contribution since planting (or between harvests) and the latter is a point estimate at the time of sampling. This was overcome by using a 'plant to plant simulation technique' where estimates of BNF are calculated from the daily accumulation of total N and the labelled N derived from the growth medium by the legumes using a curve-fitting strategy. These estimates of BNF for the days when stem extracts were analysed for nitrate and ureide showed linear correlations (r2 = 0.82 and 0.90 for the D. ovalifolium and Centrosema hybrid, respectively). This indicated that RUA of stem extracts of these two legumes was a reliable indicator of the BNF contribution, at least under controlled conditions.
650 $alegumes
650 $atracer techniques
650 $aCentrosema
650 $aDiluição Isotópica
650 $aLeguminosa Forrageira
650 $aLeguminosa Tropical
653 $aBNF
653 $aFBN
653 $aFixacao biologica de nitrogenio
653 $aNitrogen fixing bacteria
653 $aTropical zones
700 1 $aRESENDE, A. S.
700 1 $aURQUIAGA, S.
700 1 $aBODDEY, R. M.
773 $tNutrient Cycling in Agroecosystems, Netherlands$gv. 56, p. 165-176, 2000.
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