Chemical Speciation of Aluminum in Delhi Soils.

The objective of the investigation was to ascertain the status of Aluminum in Delhi soils by studying its speciation in the soil profile and to assess if there was any spatial variability. Soils representing the Aravali Ridge and the alluvial floodplains of river Yamuna were collected as a single, undisturbed core up to a depth of lm and the profile differentiated into four layers- 0-17 cm, 17-37 cm, 37-57 cm, and 57-86 cm. "Pseudo" total Aluminum and Iron in the soils were speciated into the "operationally" defined species (weakly exchangeable, organic matter complexes, amorphous oxides and hydroxides, and crystalline or "free" oxides) by widely recommended selective extraction procedures. Both Al and Fe in these soils are bound predominantly as Fe oxides and silicates and have only very low percentages in the easily mobilizable pools. [ABSTRACT FROM AUTHOR]