The researchers studied how different amounts of nitrogen, phosphorus, and potassium affect the yield and quality of onions grown during the rainy season. They conducted experiments using various combinations of these nutrients and found that higher levels of nitrogen significantly increased onion yield. However, the levels of phosphorus and potassium did not have a significant impact on the quality of the onions. The best combination of nutrients for high yield and quality was determined to be 150 kg of nitrogen, 80 kg of phosphorus, and 100 kg of potassium per hectare.