A study was done to see how different amounts of phosphorus and nitrogen affect the yield of upland rice. They also looked at using organic materials like cowpea and compost to replace some of the nitrogen. The researchers found that using 30 kg of P205 and 120 kg of N with a mix of chemical fertilizer, cowpea, and compost gave the best results. This method produced the highest grain and straw yields compared to other treatments. The harvest index was also highest with this combination.