Evaluation of phosphorus management practices in East Mediterranean altered wetland soils

In this study, we re‐examined the common practice of intensive P fertilization in altered wetland soils even when soil test (Olsen‐P) indicates sufficient P levels (>10 mg/kg). We tested the effects of P fertilization on crop performance and P leaching in 36 lysimeters (1.5 m³) filled with peat, marl or alluvial materials and compared a new bone‐char‐based fertilizer to the common superphosphate. The lysimeter experiment consisted of the two fertilizer types, two application rates and a typical crop rotation of setaria (Setaria italica), pea (Pisum sativum) and tomatoes (Lycopersicon esculentum). By the end of each crop rotation, the yield was evaluated relative to P‐fertilization rates and soil‐test P. P fertilization resulted in increased Olsen‐P, soil‐solution P and P loss through leachates and a slight quality yield advantage in pea and tomato with no increase in yield of any crop. P budget calculations showed that plant uptake was not affected by the amount or type of applied P. We concluded that P fertilizer application should be significantly reduced because of limited crop response and increased P concentrations in leachates that may increase P loss to waterways especially in the marl soils. The ABC Protector exhibited slow P release, but its environmental implications should be further studied.