Data/hora: 12/05/2024 07:32:11

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 22/07/2002
Data da última atualização: | 22/07/2002
Autoria: | CHAPUIS-LARDY, L.; BROSSARD, M.; QUIQUAMPOIX, H.
Título: | Assessing organic phosphorus status of Cerrado oxisols (Brazil) using P-NMR spectroscopy and phosphomonoesterase activity measurement.
Ano de publicação: | 2001
Fonte/Imprenta: | Candian Journal of Soil Science, Ottawa-Canada, v. 81, p. 591-601, 2001.
Idioma: | Inglês

Conteúdo:

Plant production in the Brazilian savanas, also known as the Cerrados, is limited mainly by low P avaliability  in soils. Little is known about the P status in the Cerrados region, despite its increasing significance for the contry's agriculture.
31P-NMR spectroscopy of alkali extracts and phosphomonoesterase (PME) acivity measurements were used to study forms of P and their stability in oxisols of natural and posture systems. Total P content (Pt) in topsoils ranged from 301 to 465 mg kg-1 and organic P content (Po) from 84 to 194 mg kg-1 with the highest values under natural vegetation. The estimation of forms of soil P with different lability (provided by NaHCO3 and NaOH extractions) showed little difference between natural vegetation and pastures, but the proportions of Po extracted suggest the importance of organically bound P as a source of plant-available P. All NMR spectra showed signals of organic P(monoesters and diesters) and inorganic P form(orthophosphate and phosphosphate), with little influence of land use. Organic P appears to be mainly in the form of stable phosphomonoesters. The most marked effect of land use was a decrease in PME activity under recent pastures, indicating na increase of PME stability in topsoils after the maize-grass ley plantation. The importance of the pH of the PME activity measurements is also discussed.

Palavras-Chave: | Soil testing.
Thesagro: | Análise do Solo; Cerrado; Fertilidade do Solo; Fósforo; Pastagem; Solo.
Thesaurus Nal: | pastures; phosphorus; soil; soil fertility.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (21533-1) - UPC - SP - -- - CRI5957 -  - CRI5957 - DIS