Researchers studied how different amounts of nitrogen, phosphorus, and potassium, along with plant density, affect rice grain yield and quality. They found that too much nitrogen led to late maturity, poor grain filling, and low quality in one rice variety. The optimal nitrogen amount for high yield varied between rice varieties. Plant spacing affected grain yield, with closer spacing benefiting one variety and wider spacing benefiting another. Increasing spacing reduced panicles but increased spikelets per panicle. Exceeding certain spacing or seeding rates decreased milling quality. Certain relationships were observed, such as higher brown rice rate correlating with higher milled rice rate.