The use of agro-industrial wastewater can reduce environmental pollution and emissions of greenhouse gases into the atmosphere. One of them is by utilizing its acidity to dissolve phosphate rock (PR) which is used for P fertilizer. The purpose of this study was to determine the effect of agro-industrial wastewater and PR dosage for P availability and nutrient uptake by corn in ultisol soil. Split plot design was arranged with wastewater of tapioca and tofu as a main factor and dosage of PR after acidulation as a sub-plot. The results showed that wastewater had no effect on the available soil P, soil pH, N uptake, P uptake, and dry weights of corn plants, but PR dosage had a significant effect on available soil P, N uptake. There is an interaction between agro-industrial wastewater and PR dosage on the P availability. For acidulation with tofu wastewater, the PR dosage used is lower for the same soil P availability compared to tapioca wastewater. At high P dosages, acidulation PR with wastewater does not have a significant effect on soil P availability. Phosphorus and nitrogen uptake by corn increased with the application of 950 kg ha-1 acidulated PR.