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| Registros recuperados : 62 | |
| 21. |  | WESTERHOF, R.; BUURMAN, P.; GRIETHUYSEN, C. van; AYARZA, M. A.; VILELA, L.; ZECH, W. Aggregation studied by laser diffraction in relation to plowing and liming in the Cerrado region in Brazil. Geoderma, Amsterdam, v.90, p.277-290, 1999.| Biblioteca(s): Embrapa Cerrados. |
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| 22. | | WESTERHOF, R.; BUURMAN, P.; GRIETHUYSEN, C. van; AYARZA, M. A.; VILELA, L.; ZECH, W. Aggregation studied by laser diffraction in relation to plowing, soil organic matter, and lime in the Brazilian cerrados. In: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999. p.64-76.| Biblioteca(s): Embrapa Cerrados. |
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| 25. | | LILIENFEIN, J.; WILCKE, W.; AYARZA, M. A.; LIMA, S. do C.; VILELA, L.; ZECH, W. Annual course of matric potential in differently used savanna oxisols in Brazil. Soil Society of American Journal, Madison, v.63, p.1778-1785, 1999.| Biblioteca(s): Embrapa Cerrados. |
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| 26. | | THOMAS, R. J.; FISHER, M.; LASCANO, C.; RAO, I. M.; AYARZA, M.; ASAKAWA, N. Nutrient cycling via forage litter in tropical grass-legume pastures. In: Proceedings of the XVII International Grassland Congress, New Zealand., v., p.508-509, 1994.| Biblioteca(s): Embrapa Agrobiologia. |
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| 29. | | PIZARRO, E. A.; AYARZA, M. A.; SPAIN, J. M.; CARVALHO, M. A.; SOUZA, M. A. de. Efecto de la irrigacion en la produccion de semillas de Stylosanthes guianensis cv. Mineirao. Pasturas Tropicales, Cali, v.15, n.3, p.27-28, 1993.| Biblioteca(s): Embrapa Cerrados. |
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| 32. | | LILIENFEIN, J.; WILCKE, W.; AYARZA, M. A.; VILELA, L.; LIMA, S. do C.; ZECH, W. Chemical fractionation of phosphorus, sulphur, and molybdenum in Brazilian savannah oxisols under different land use. Geoderma, Amsterdam, v. 96, p. 31-46, 2000.| Biblioteca(s): Embrapa Cerrados. |
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| 33. | | SMITH, J.; CADAVID, J. V.; AYARZA, M.; AGUIAR, J. L. P. de; ROSA, R. Land use change in soybean production systems in the Brazilian savanna: the role of policy and market conditions. Journal of Sustainable Agriculture, Binghamton, v.15, n.2/3, p.95-117, 1999.| Biblioteca(s): Embrapa Cerrados. |
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| 34. | | LILIENFEIN, J.; WILCKE, W.; NEUFELDT, M.; AYARZA, M. A.; ZECH, W. Land-use effects on organic carbon, nitrogen, and sulphur concentrations in macroaggregates of differently textured Brazilian oxisols. Journal of Plant Nutrition and Soil Science, Berlin, v.161, n.2, p.165-171, 1998.| Biblioteca(s): Embrapa Cerrados. |
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| 37. | | AYARZA, M. A.; VILELA, L.; BARCELLOS, A. de O.; BALBINO, L. C.; BROSSARD, M.; PASINI, A. Integration culture-elevage dans les cerrados au Brasil: une solution pour des systemes durables. Agriculture et Developpement, Montpellier, n.18, p.91-98, juin 1998.| Biblioteca(s): Embrapa Cerrados. |
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| 38. | | AYARZA, M. A.; VILELA, L.; BARCELLOS, A. de O.; BALBINO, L. C.; BROSSARD, M.; PASINI, A. Integration culture-elevage dans les cerrados au Bresil: une solution pour des systemes durables. Agriculture et Developpement, Montpellier, n. 18, p. 91-98, juin 1998.| Biblioteca(s): Embrapa Arroz e Feijão. |
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| 39. | | RAMOS, A. K. B.; PIZARRO, E. A.; AYARZA, M. A.; CARVALHO, M. A.; COSTA, P. H. Avaliacao agronomica de gramineas forrageiras consorciadas com Stylosanthes guianensis Cv. Mineirao em Uberlandia - MG. In: REUNIAO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 33., 1996, Fortaleza, CE. Anais... Fortaleza: SBZ, 1996. v.2. p.206-208.| Biblioteca(s): Embrapa Cerrados. |
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| 40. | | PIZARRO, E. A.; RAMOS, A. K. B.; AYARZA, M. A.; CARVALHO, M. A.; COSTA, P. H. Avaliacao agronomica de leguminosas forrageiras consorciadas com B. decumbens em Uberlandia - MG. In: REUNIAO ANUAL DA SOCIEDADE BRASILEIRA DE ZOOTECNIA, 33., 1996, Fortaleza, CE. Anais... Fortaleza: SBZ, 1996. v.2. p.209-211.| Biblioteca(s): Embrapa Cerrados. |
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| Registros recuperados : 62 | |
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Registro Completo
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Biblioteca(s): |
Embrapa Cerrados. |
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Data corrente: |
16/07/1999 |
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Data da última atualização: |
16/07/1999 |
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Autoria: |
RENZ, T. E.; NEUFELDT, H.; AYARZA, M. A.; SILVA, J. E. da; ZECH, W. |
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Título: |
Acid monophosphatase: an indicator of phosphorus mineralization or of microbial activity? a case study from Brazilian cerrados. |
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Ano de publicação: |
1999 |
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Fonte/Imprenta: |
In: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999. |
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Páginas: |
p.173-186. |
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Idioma: |
Inglês |
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Conteúdo: |
Plant production in the Brazilian savannas, also known as the Cerrados, is limited mainly by low P availability. In tropical soils, rich in sesquioxides, P supply of plants depends heavily on the transformation of organic P by phosphatase enzymes into HPO and H2PO4. We examined two Oxisols-one clayey and one loamy-under different land uses for their potential acid monophophatase activity (PAMA) and potential microbial activity. We measured dimenthyl sulfoxide reduction, pH, total C and N, and NaOH-extractable organic and inorganic P. For all parameters other than pH, values were about twice as high in the clayey as in the loamy soil. Land use was found to strongly affect phosphatase activity, which was reduced by both cropping and reforestation. In the clayey soil, pastures seemed to have a positive effect of continuous cropping to pastures resulted in a rapid recovery of phosphatase activity, microbial activity, and C and N levels. However, it retained high inorganic P (Pi) levels found in fertilizer crops. A comparasion of phosphatase activity with microbial activity, total C and N, and P fractions showed that phosphatase was strongly related to microbial activity in the soil and therefore depended much more on soil organic matter than on soil P levels. We also found that although PAMA is useful for indicating a soil's P mineralization capacity, it does not indicate actual P mineralization rates. However, when combined with findings for microbial activity and Pi, it indicates the level of microbially available P, a lack of which probably implies strong competition between plants and microorganisms for this element. MenosPlant production in the Brazilian savannas, also known as the Cerrados, is limited mainly by low P availability. In tropical soils, rich in sesquioxides, P supply of plants depends heavily on the transformation of organic P by phosphatase enzymes into HPO and H2PO4. We examined two Oxisols-one clayey and one loamy-under different land uses for their potential acid monophophatase activity (PAMA) and potential microbial activity. We measured dimenthyl sulfoxide reduction, pH, total C and N, and NaOH-extractable organic and inorganic P. For all parameters other than pH, values were about twice as high in the clayey as in the loamy soil. Land use was found to strongly affect phosphatase activity, which was reduced by both cropping and reforestation. In the clayey soil, pastures seemed to have a positive effect of continuous cropping to pastures resulted in a rapid recovery of phosphatase activity, microbial activity, and C and N levels. However, it retained high inorganic P (Pi) levels found in fertilizer crops. A comparasion of phosphatase activity with microbial activity, total C and N, and P fractions showed that phosphatase was strongly related to microbial activity in the soil and therefore depended much more on soil organic matter than on soil P levels. We also found that although PAMA is useful for indicating a soil's P mineralization capacity, it does not indicate actual P mineralization rates. However, when combined with findings for microbial activity and Pi, it indica... Mostrar Tudo |
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Thesagro: |
Cerrado; Fosfatase Ácida; Fósforo; Oxisol; Solo. |
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Thesaurus NAL: |
acid phosphatase; Ferralsols; phosphorus; soil. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02561naa a2200289 a 4500
001 1545409
005 1999-07-16
008 1999 bl uuuu u00u1 u #d
100 1 $aRENZ, T. E.
245 $aAcid monophosphatase$ban indicator of phosphorus mineralization or of microbial activity? a case study from Brazilian cerrados.
260 $c1999
300 $ap.173-186.
520 $aPlant production in the Brazilian savannas, also known as the Cerrados, is limited mainly by low P availability. In tropical soils, rich in sesquioxides, P supply of plants depends heavily on the transformation of organic P by phosphatase enzymes into HPO and H2PO4. We examined two Oxisols-one clayey and one loamy-under different land uses for their potential acid monophophatase activity (PAMA) and potential microbial activity. We measured dimenthyl sulfoxide reduction, pH, total C and N, and NaOH-extractable organic and inorganic P. For all parameters other than pH, values were about twice as high in the clayey as in the loamy soil. Land use was found to strongly affect phosphatase activity, which was reduced by both cropping and reforestation. In the clayey soil, pastures seemed to have a positive effect of continuous cropping to pastures resulted in a rapid recovery of phosphatase activity, microbial activity, and C and N levels. However, it retained high inorganic P (Pi) levels found in fertilizer crops. A comparasion of phosphatase activity with microbial activity, total C and N, and P fractions showed that phosphatase was strongly related to microbial activity in the soil and therefore depended much more on soil organic matter than on soil P levels. We also found that although PAMA is useful for indicating a soil's P mineralization capacity, it does not indicate actual P mineralization rates. However, when combined with findings for microbial activity and Pi, it indicates the level of microbially available P, a lack of which probably implies strong competition between plants and microorganisms for this element.
650 $aacid phosphatase
650 $aFerralsols
650 $aphosphorus
650 $asoil
650 $aCerrado
650 $aFosfatase Ácida
650 $aFósforo
650 $aOxisol
650 $aSolo
700 1 $aNEUFELDT, H.
700 1 $aAYARZA, M. A.
700 1 $aSILVA, J. E. da
700 1 $aZECH, W.
773 $tIn: THOMAS, R.; AYARZA, M.A., ed. Sustainable land management for the oxisols of the Latin American savannas: dynamics of soil organic matter and indicators of soil quality. Cali: CIAT, 1999.
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