Influence of Temperature and Moisture on Soil Phosphorus I. Effect on Soil Phosphorus Fractions

Soil incubated at −20.5° C. for 9 months released more phosphorus when leached with water than soil incubated at 2.7° C. At a leaching temperature of 32° C. more phosphorus was released than at 16° C. The amount of phosphorus released was correlated with a decrease in acid‐soluble phosphorus and an increase in alkali‐soluble phosphorus (iron phosphate) in the soil after leaching. It is suggested that preconditioning temperature changes either the types of phosphorus compounds or the surface area of those present in the soil. Incubating under anaerobic conditions increased the alkali‐soluble phosphorus; however, this phosphorus did not contribute to the supply of phosphorus available to the plant.