Phosphorus Dynamics in a Luvic Phaeozem After 50 Years of Different P Fertilization

After 50 years of differentiated P fertilization great differences in plant-available P contents between the treatments were measured. However, yield and P uptake varied marginally and only in few plant species these parameters changed significantly. Investigations of P availability, P release and P sorption in different soil depths should show, which phosphorus fractions are important for P supply of agricultural plants in a Luvic Phaeozem. This information can be used for the improvement of fertilization recommendations. A significant decrease in DL-soluble P content in P0 and P15 treatments down to a soil depth of 60cm was measured. Diffusible P content was substantially higher in the P45 treatment in comparison to P0 and P15. Subsoil seems to be an important additional P source. Plant species have a significant influence on phosphorus dynamic. High P sorption in the investigated Luvic Phaeozem, which could not be reduced by excessive P fertilization, may be one of the reasons for low fertilization efficiency in this trial.