Potassium can enhance plant to tolerate drought. The availability of potassium in the soil can increase with various amendments. Application organic manure to the soils increased potassium release and decrease potassium fixation in soils. Application of phosphorous fertilizer increased root biomass, photosynthesis rate and leaf water content under water stress. In this study, organic fertilizer and various sources of phosphorus were applied to the soil under the different quantity of water irrigation to evaluate potassium availability during different stages of Maize growth. The result showed that the addition of organic fertilizer increased the availability of potassium in soil at all plant stage growth. The higher quantity of water irrigation had a significantly higher concentration of potassium availability during the growth and flowering stage of Maize. However, different water quantity had no significantly effected potassium availability during the mature stage. The application of organic fertilizer and/or phosphorus fertilizer had significantly increased potassium availability as compared to the control treatment during all stage Maize growth. The interactions between treatments had significantly increased concentration of potassium availability during all stages of Maize. Therefore, organic matter and phosphorous can increased plant tolerate to drought.