Technical Abstract: Poultry litter is being incinerated in order to reduce excess litter and to increase the percentage of renewable fuel used to generate electricity. Ash from incinerated litter has been effective in increasing crop growth. However, there is no current literature comparing phosphorus availability from broiler litter ash (BLA) and layer manure ash (LMA) for growth, phosphorus and arsenic uptake by corn, wheat and soybean plants. The objective of this study was to determine the availability of phosphorus from BLA and LMA for corn, wheat and soybean growth, phosphorus and arsenic uptake when compared to calcium phosphate. The BLA, LMA and calcium phosphate were mixed with a low phosphorus soil at two rates (40 and 80 mg P kg-1). Phosphorus rates were based on the total P in the ash. All crops were grown for five weeks after planting. Biomass and phosphorus concentrations for the crops grown on the calcium phosphate treatment were higher than or equal to that of the BLA and LMA treatments. At the highest P rate, corn tissue phosphorus were 1135, 963 and 939 mg kg-1 for calcium phosphate BLA and LMA respectively. Arsenic concentrations in plants grown on the ash treatment were lower than or equal to the control. The low tissue phosphorus observed indicates that phosphorus in the ash was not as available for crop uptake and did not become more available with each crop. Further studies with these ashes are needed to determine the appropriate rate needed to supply sufficient phosphorus for crop uptake.