Within season variability of bicarbonate extractable phosphorus in wheat soils

Abstract

Using a long-term experiment at Longerenong Agricultural College, Dooen, Vic., plots from a pasture-pasture-fallow-wheat rotation were sampled on a three-weekly basis for a year. Analysis of the samples by bicarbonate extraction for phosphorus indicated considerable short-term fluctuations in phosphorus which were only partially explained by environmental conditions. Bicarbonate extractable phosphorus was both lowest and less variable over time under a two-year pasture treatment than when under fallow.