Researchers conducted an experiment to find the best amounts of nitrogen, phosphorus, and potassium fertilizers for cassava plants in Hainan Province. They discovered that applying 300 kg of nitrogen, 120 kg of phosphorus, and 450 kg of potassium per hectare led to the highest yield. The optimal fertilizer rates for maximum yield were found to be 399.46 kg of nitrogen, 124.09 kg of phosphorus, and 481.82 kg of potassium per hectare. Based on these results, they recommend a fertilizer range of 220-320 kg of nitrogen, 72-98 kg of phosphorus, and 200-380 kg of potassium per hectare for cassava production in the area.