Comparison of Various Extractants for Evaluating Phosphorus Availability to Plants in Saudi Arabia Soils

Abstract

Twenty two soil samples from important agricultural areas in the Kingdom, chiefly in the central region, were used in the present experiment. They show wide variability in chemical, physical as well as in extractable P. Distilled water, NaHCO3 NH4HCO3-DTPA and NH4F-HCI were used to determine extractable P in the soils. The P soil test values were then correlated with various yield and P uptake parameters obtained from a greenhouse pot experiment using corn as a test crop. With the exception of the NH4 F-HCI test, all the other tests yielded highly to very highly significant correlations, indicating that they were equally effective in evaluating the P status of the soils for plant growth. By relating the P test values to relative yields, useful impressions of critical levels for the soil tests used were obtained