Long-term use of manure and chemical fertilizers in acidic paddy soil boosts crop yield and soil fertility. Combining manure with chemical fertilizers leads to higher crop yield and sustainability compared to using only chemical fertilizers. The best results were seen with the NPKM treatment. Soil organic carbon levels increased with manure and chemical fertilization, while nutrient uptake also improved. However, using manure with inorganic phosphorus fertilizer can lead to excess phosphorus in the soil, which should be monitored. Factors like soil nitrogen, organic carbon, and total nitrogen play a significant role in determining crop yield. Overall, combining manure with inorganic fertilizers is beneficial for crop yield sustainability and organic carbon sequestration in acidic paddy soil.