Phosphorus in the coarse soil fraction is related to soil organic phosphorus mineralization measured by isotopic dilution

A sound prediction of soil organic phosphorus (Po) mineralization would be helpful to improve fertilizer recommendations. However in most mineral soils expensive and time consuming isotopic dilution experiments are required to assess Po mineralization. A proposed method to estimate Po mineralization is the quantification of P in the coarse fraction (CF >53 µm) of the soil. The aim of this study was to evaluate if P in the CF can effectively predict Po mineralization. Soil samples from three North American long term arable field experiments (>10 years) with different textures (sand content 15 to 82) and different fertilization treatments (non P fertilized mineral P fertilizer poultry litter) were analyzed. Soil samples were physically fractioned into CF and fine fraction (FF