Importance of pools varies with nutrients Phosphorus (P) Both inorganic and organic pools in soil Organic P: 5-100kg P/ha Absorbed soil phosphate(inorganic P): 20 500kg soil solution: anions(H2PO4/HPO42-, depends on pH): 0. 1-2uM High buffering capacity◼ Phosphorus (P) ◼ Both inorganic and organic pools in soil ◼ Organic P: 5-100kg P/ha ◼ Absorbed soil phosphate (inorganic P): 20- 500kg ◼ soil solution: anions (H2PO4 - /HPO4 2- ,depends on pH); 0.1-2μM ◼ High buffering capacity Importance of pools varies with nutrients