In a world with high demand in P for the maintenance of soil fertility and crop productivity, this chapter introduced the types and sources of P fertilizers in soil. Specifically chemical fertilizers were discussed, with phosphate rock being the primary source of phosphate, versus organic phosphate fertilizers, such as P humates and organominerals. Moreover, novel composite materials that have been used as P-adsorption agents are proposed as an alternative source of soil P fertilizers, which could be effective soil conditioners, slowly releasing macro- and micro-nutrients in agricultural soils.