Biogenic calcium phosphate transformation in soils over millennial time scales
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
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Data(s) |
20/10/2012
20/10/2012
2009
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Resumo |
Changes in bioavailability of phosphorus (P) during pedogenesis and ecosystem development have been shown for geogenic calcium phosphate (Ca-P). However, very little is known about long-term changes of biogenic Ca-P in soil. Long-term transformation characteristics of biogenic Ca-P were examined using anthropogenic soils along a chronosequence from centennial to millennial time scales. Phosphorus fractionation of Anthrosols resulted in overall consistency with the Walker and Syers model of geogenic Ca-P transformation during pedogenesis. The biogenic Ca-P (e.g., animal and fish bones) disappeared to 3% of total P within the first ca. 2,000 years of soil development. This change concurred with increases in P adsorbed on metal-oxides surfaces, organic P, and occluded P at different pedogenic time. Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy revealed that the crystalline and therefore thermodynamically most stable biogenic Ca-P was transformed into more soluble forms of Ca-P over time. While crystalline hydroxyapatite (34% of total P) dominated Ca-P species after about 600-1,000 years, beta-tricalcium phosphate increased to 16% of total P after 900-1,100 years, after which both Ca-P species disappeared. Iron-associated P was observable concurrently with Ca-P disappearance. Soluble P and organic P determined by XANES maintained relatively constant (58-65%) across the time scale studied. Disappearance of crystalline biogenic Ca-P on a time scale of a few thousand years appears to be ten times faster than that of geogenic Ca-P. NSF-DEB[DEB-0425995] NSF-DEB US Department of Energy (DOE)[DE-AC02-76CH00016] U.S. Department of Energy (DOE) |
Identificador |
JOURNAL OF SOILS AND SEDIMENTS, v.9, n.3, p.194-205, 2009 1439-0108 http://producao.usp.br/handle/BDPI/32212 10.1007/s11368-009-0082-0 |
Idioma(s) |
eng |
Publicador |
SPRINGER HEIDELBERG |
Relação |
Journal of Soils and Sediments |
Direitos |
restrictedAccess Copyright SPRINGER HEIDELBERG |
Palavras-Chave | #Adsorption #Amazonian Dark Earths #Anthrosols #Dissolution #Organic phosphorus #Oxisols #Phosphorus transformation #Speciation #Terra Preta de Indio #XANES (X-ray absorption near-edge structure) #INDIAN BLACK EARTH #PHOSPHORUS TRANSFORMATIONS #ORGANIC PHOSPHORUS #XANES SPECTROSCOPY #WESTERN AMAZONIA #TROPICAL FOREST #CHRONOSEQUENCE #PEDOGENESIS #SPECIATION #BIOGEOCHEMISTRY #Geosciences, Multidisciplinary #Soil Science |
Tipo |
article original article publishedVersion |