The current work was conducted to illustrate the effect of some organic waste materials on enriching calcareous soils with phosphorus, iron and manganese. The organic waste materials under study were farmyard manure (FYM), sewage sludge (SS) and biogas manure (BM). The calcareous soils under investigation were taken from El-Noubaria, Maryout and El-Ameria regions which vary widely in their contents of CaCO3. Each soil was incubated separately with the organic waste material at a rate of 2 % for different periods extended up to eight weeks. Results showed significant increases in the incubated soils contents of P, Fe and Mn as compared with the unmanured soils. However, the extent of increase seemed to be more affected by the original soil content of the nutritive elements under study than the soils contents of CaCO3. The organic waste materials exerted an effect on availability of P, Fe and Mn counteracted, to some extent, the adverse effect of CaCO3. Thus, it was concluded that organic waste materials can be used as sources of nutritive elements, yet heavy application of such waste materials might on the long term lead to accumulation of heavy metals in dangerous level. High pH and CaCO3 content of the calcareous soils may be considered as an advantage prevents toxic hazard of such heavy elements.