The study looked at how planting density, corn variety, and fertilizer application affect corn yield. They found that the best planting density was 3699 plants per 667 square meters, resulting in a yield of 652 kg per 667 square meters. The highest yield for one corn variety was achieved with a specific combination of nitrogen, phosphorus, and potassium fertilizers. Overall, the amount of potassium fertilizer did not significantly impact yield compared to nitrogen and phosphorus.