Biology and Fertility of Soils

, Volume 31, Issue 1, pp 30–37

Land-use effects on phosphorus fractions in Cerrado oxisols

  • H. Neufeldt
  • J.E. da Silva
  • M. A. Ayarza
  • W. Zech
ORIGINAL PAPER

DOI: 10.1007/s003740050620

Cite this article as:
Neufeldt, H., da Silva, J., Ayarza, M. et al. Biol Fertil Soils (2000) 31: 30. doi:10.1007/s003740050620

Abstract

 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 increased levels of inorganic P (Pi) forms, the increase being most accentuated 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 particle-size 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 an effective method with which to detect the presence of fertiliser-P residues in the coarse-silt fraction.

Key words Sequential phosphorus fractionation Organic phosphorus Particle-size separation Central Brazil 

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • H. Neufeldt
    • 1
  • J.E. da Silva
    • 2
  • M. A. Ayarza
    • 3
  • W. Zech
    • 1
  1. 1.Institute of Soil Science and Soil Geography, University of Bayreuth, D-95440 Bayreuth, Germany e-mail: henry.neufeldt@uni-bayreuth.de Fax: +49-921-55-2246DE
  2. 2.Centro de Pesquisa Agropecuária dos Cerrados (EMBRAPA-CPAC), CP 08223, 73301-970 Planaltina, DF, BrazilBR
  3. 3.Centro Internacional de Agricultura Tropical (CIAT), AA 6713, Cali, ColombiaCO

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