Forms of P taken up Most P is taken up by roots as inorganic orthophosphate ions(H2 PO4 and HPO42) Roots may absorb some organic p but the amount is very small The polyphosphate(聚磷酸) was only taken up by young barley plants after hydrolysis to the orthophosphate(正磷酸) formForms of P taken up • Most P is taken up by roots as inorganic orthophosphate ions (H2PO4 - and HPO4 2- ) • Roots may absorb some organic P, but the amount is very small. • The polyphosphate(聚磷酸) was only taken up by young barley plants after hydrolysis to the orthophosphate(正磷酸) form