Soil Phosphorus Fractions and their Avilability to Corn Plants in Some Saudi Calcareous Soils

Abstract

The study has supplied data on phosphorus fractions in twenty two agricultural important Saudi soils. They show wide variability in total phosphorus (437 to 970 ppm) and organic phosphorus (0.5 to 18.2 ppm). Total phosphorus and organic phosphorus were found increased in relatively heavier (P<0.05) and organic matter -rich soils (P<0.01). Calcium-bound P (Ca-P) appeared to be of a little importance as a short term "source" of P for corn plants (zea mays L.), although it constituted up to 86% of the total P in soils. Aluminium-bound P (Al-P) and water-soluble P (Sol-P), though of comparatively little occurrence in the soils, appears to play a significant role in P supply (P< 0.01) to corn plants.