Maximum crop production is dependent on adequate phosphorus (P) supply from fertilizers because release of plant-available P from primary minerals in soils is generally too slow to meet P requirements of crops. Phosphorus fertilizers are obtained from phosphate rock, a non-renewable resource whose reserves are finite. The limited reserves of phosphate rock challenges the long term sustainability of crop production; as such it is important to recover and recycle P contained in organic wastes. While use of organic wastes is crucial, for them to be widely adopted as alternative P fertilizers, their P availability for plant use should be predictable. This dissertation describes how three organic P fertilizers (composted chicken manure, anaerobically digested dairy (AD) manure and vegetable compost) compare to mono-ammonium phosphate (MAP), a mineral P fertilizer. Comparisons were made on (i) P availability and P fractions in five soils (ii) above ground biomass and tissue P response of corn (Zea mays L.), (iii) crop yield and leaf P concentration in corn and pinto bean (Phaseolus vulgaris L.) and (iv) post-harvest soil quality indices. Results showed that corn above ground biomass and tissue P in soils amended with the three organic P fertilizers were similar with those from MAP when soils had medium initial P content and lower iron and calcium content. In soils where initial P concentrations are lower and calcium or iron content are high, MAP outperformed the three organic P fertilizers. Application of composted chicken manure and AD dairy manure increased the readily available P fractions in a similar magnitude as mineral P fertilizer. There were no corn and pinto bean yield effects when either organic P fertilizers or MAP were used. Reponses in corn and bean leaf P concentrations were only observed at rates that were twice or four times the recommended amount and these responses were comparable between organic P fertilizers and MAP. Findings from this dissertation suggest that composted chicken manure and AD dairy manure can effectively be used as a substitute for the mineral P source.