Long-term use of green manure with chemical fertilizers helps increase rice yield and soil nutrients in paddy fields. The study found that combining green manure with fertilizers leads to stable and high rice yields, reduces the need for fertilizers, and improves nutrient efficiency. The treatment with Chinese milkvetch and pig manure had the highest rice yield over 26 years. Soil organic matter, total nitrogen, and total phosphorus increased with green-chemical fertilizer applications. However, soil potassium levels were deficient, with the treatment using Chinese milkvetch and fresh rice straw being the most effective in increasing potassium levels. The study also showed that soil total potassium had the highest correlation with rice yield, indicating that potassium deficiency is a key factor for high rice yields in paddy soils.