The researchers studied how different plant densities and nitrogen levels affect the yield of sweet corn. They planted sweet corn seeds at varying densities and nitrogen rates, then measured factors like ear number, grain weight, and yield. They found that higher plant density led to more ears and grain yield, but at the expense of ear weight. The best treatment for sandy soil was high plant density and low nitrogen rate. The key factors influencing grain yield were grain number and grain weight, which accounted for 98% of the variation. Increasing these factors through higher plant density can improve sweet corn yield.