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Registro Completo |
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Biblioteca(s): |
Embrapa Semiárido. |
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Data corrente: |
18/09/2013 |
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Data da última atualização: |
18/09/2013 |
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Autoria: |
VIDAL PÉREZ, D.; ALCANTARA, S.; ARRUDA, R. J.; MENEGHELLI, N. A. |
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Título: |
Comparing two methods for soil carbon and nitrogen determination using selected Brazilian soils. |
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Ano de publicação: |
2001 |
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Fonte/Imprenta: |
Communications in Soil Science and Plant Analysis, v. 32, N. 1/2, p. 295-309, 2001. |
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Idioma: |
Inglês |
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Conteúdo: |
Considering the increasing need for reliable soil carbon (C) and nitrogen (N) determinations, 19 Brazilian soil samples were selected to compare the results of two methods (a) a modified dichromate wet digestion and Kjeldahl that has been in use by Embrapa in most of Brazilian soil surveys (Embrapa's method), and (b) an automated technique based on dry combustion (Perkin-Elmer 2.400 Series II?CHN Mode). Considering that the last method is very much influenced by sample size, two weights were tested (10 and 100 mg). The influence of two particle sizes for both methods (crushed and sieved to pass a 0.177-mm mesh) was also tested. A simple linear regression with the confidence limits for the intercept and slope were used to compare methods. Precision was evaluated by the coefficient of variation (C.V.). The results showed that simple crushing is inadequate for performance analysis by dry combustion mainly for small samples (10 mg), where the precision is also low (19.77% for N and 9.41% for C). The dry combustion method is significantly affected by the use of small samples (10 mg), mainly for N analysis. For finely ground samples (< 0.177 mm), a comparison of the results obtained by dry combustion (100 mg weight sample) and by Embrapa's method showed a significant 1:1 relation. Thus the use of correction factor is not necessary. |
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Palavras-Chave: |
Natural resource; Recursos naturais. |
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Thesagro: |
Carbono; Nitrogênio; Solo. |
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Thesaurus Nal: |
Soil. |
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Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
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Marc: |
LEADER 02033naa a2200229 a 4500
001 1966491
005 2013-09-18
008 2001 bl uuuu u00u1 u #d
100 1 $aVIDAL PÉREZ, D.
245 $aComparing two methods for soil carbon and nitrogen determination using selected Brazilian soils.$h[electronic resource]
260 $c2001
520 $aConsidering the increasing need for reliable soil carbon (C) and nitrogen (N) determinations, 19 Brazilian soil samples were selected to compare the results of two methods (a) a modified dichromate wet digestion and Kjeldahl that has been in use by Embrapa in most of Brazilian soil surveys (Embrapa's method), and (b) an automated technique based on dry combustion (Perkin-Elmer 2.400 Series II?CHN Mode). Considering that the last method is very much influenced by sample size, two weights were tested (10 and 100 mg). The influence of two particle sizes for both methods (crushed and sieved to pass a 0.177-mm mesh) was also tested. A simple linear regression with the confidence limits for the intercept and slope were used to compare methods. Precision was evaluated by the coefficient of variation (C.V.). The results showed that simple crushing is inadequate for performance analysis by dry combustion mainly for small samples (10 mg), where the precision is also low (19.77% for N and 9.41% for C). The dry combustion method is significantly affected by the use of small samples (10 mg), mainly for N analysis. For finely ground samples (< 0.177 mm), a comparison of the results obtained by dry combustion (100 mg weight sample) and by Embrapa's method showed a significant 1:1 relation. Thus the use of correction factor is not necessary.
650 $aSoil
650 $aCarbono
650 $aNitrogênio
650 $aSolo
653 $aNatural resource
653 $aRecursos naturais
700 1 $aALCANTARA, S.
700 1 $aARRUDA, R. J.
700 1 $aMENEGHELLI, N. A.
773 $tCommunications in Soil Science and Plant Analysis$gv. 32, N. 1/2, p. 295-309, 2001.
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Registro original: |
Embrapa Semiárido (CPATSA) |
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