The primary issue in managing Ultisol is its low fertility level. Actions that can be taken to address this issue include fertilization. Frequent use of inorganic fertilizers can lead to a decline in soil productivity, making it essential to incorporate organic material. The objective of this study is to investigate how the use of organic materials, specifically POC tofu waste and chicken manure, impacts the availability of NPK nutrients and N-plant absorption in Ultisol, as well as to determine which combination of treatment doses most significantly affects the availability of NPK nutrients and N-plant uptake in the soil. Soil samples were analyzed in the laboratory and subsequently, the data was assessed using the DMRT approach. The results of the study indicated that the blend of tofu waste POC and chicken manure influenced variations in pH and soil available N. In contrast, the treatment did not impact available P, available K, dry weight, or plant N uptake. In addition to that, the combination of 200 ml tofu waste POC with 0 ton ha-¹ chicken manure (P₂K₀), 200 ml tofu waste POC with 7,5 ton ha-¹ chicken manure (P₂K₁), and 200 ml tofu waste POC with 15 ton ha-¹ chicken manure (P₂K₂) yields the best outcomes for variations in soil pH values. Specifically, applying 200 ml tofu waste POC and 15 ton ha-¹ chicken manure (P₂K₂) results in the highest effectiveness on changes in the soil available N.