Fractionation and mobility of phosphorus in grassland soils

 Research questions:

• Are the different P pools in the soil enriched differently through long-term fertilization?
• What influence does the amount of P fertilizer applied annually have?
• Are there differences between mineral and organic fertilization?
• Which P pools in the soil are preferentially enriched in the absence of fertilization?
• Are there differences between different depth levels in the ground when it comes to P pools?