In this research available iron was measured in 21 calcareous surface soil samples (0-30 cm) by five methods including DTPA, AB-DTPA, AC-EDTA, hydroxylamine, reference ammonium oxalate and rapid ammonium oxalate. Fe fractions were also determined by the modified sequential extraction procedures introduced by Singh et al. According to results, rapid ammonium oxalate and AC-EDTA methods extracted...
