Data/hora: 28/05/2024 10:58:19

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 03/05/2001
Data da última atualização: | 03/05/2001
Autoria: | NEUFELDT, H.; SILVA, J. E. da; AYARZA, M. A.; ZECH, W.
Título: | Land-use effects on phosphorus fractions in Cerrado oxisols.
Ano de publicação: | 2000
Fonte/Imprenta: | Biology and Fertility of Soils, Heidelberger, v.31, p.30-37, 2000.
Idioma: | Inglês
Conteúdo: | Differently managed oxisols from Central Brazil were studied using a sequential P fractionation procedure because the effects of land use on the distribution of P forms in these soils are barely known. Therefore levels of labile and recalcitrant P forms in the natural Cerrado savanna were compared with those of crop, pasture and reforestation sites on differently textured oxisols. Under natural conditions of strong P deficiency, >60% of labile P was organic P (Po), reflecting the high contribution of Po to plant nutrition. Fertilisation after land-use change only incresead levels of inorganic P (Pi) forms, the increase being mot acentuated in the labile Pi fraction. At the crop and the pasture sites P tended to accumulate as recalcitrant P forms in the clayey soils, while in the loamy soils there was only a minor enrichment, probably due to the lower amounts of Fe- and Al-(hydr)oxides. In the reforestation sites, labile P was maintained at high levels most likely through efficient recycling of the litter. The P fractionation procedure was also applied to particlesize fractions which reflected P transformations along an organic and mineralogical gradient. The clay fraction corresponded to 69-87% of total P and appeared to be both a sink for highly recalcitrant P and a source for labile P, especially labile Po. The sequential P fractionation procedure was also na effective method with which to detect the presence of fertiliser-P residues in the coarse-silt fraction.
Thesagro: | Cerrado; Fósforo; Fracionamento; Oxisol; Uso da Terra.
Thesaurus Nal: | Ferralsols; fractionation; land use; phosphorus.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (3809-1) - UPC - SP - -- - CRI5505 -  - CRI5505 - DIS