Development of an alternative to the olsen test for determining corn plant-available phosphorus in calcareous soils

Abstract

In this research, several chemical extractants and modified Olsen methods were studied in 25 surface-calcareous soils (0-30 cm) for determining available phosphorus (P) for corn (Zea mays L.) plant. In this experiment, the highest correlation was obtained between extracted P by Olsen and Colwell methods (NaHCO3-extractable P) and dry weight of corn shoot (r =0.67 and 0.75, p