A Modified Chang and Jackson Procedure for Routine Fractionation of Inorganic Soil Phosphates

Abstract
A method is described for the routine fractionation of inorganic soil phosphates. Use of constant suction pipettes, two molybdophosphoric reductants with different sensitivities, and an isobutyl alcohol extraction for the determination of reductant soluble phosphates greatly increased the speed of the phosphorus determinations. Results from 100 deplicated soil samples had average coefficients of variation and correlation between duplicates within samples for the four phosphate fractions of 3.7% and 0.998, respectively.
Funding Information
  • University Research Committee, Emory University
  • Wisconsin Alumni Research Foundation