The study looked at how different amounts of potassium fertilizer affect the growth and yield of high-yield rice in red paddy soil. They tested two rice varieties with varying levels of potassium in the soil. The researchers found that the amount of potassium in the soil affected the number of grains produced, plant height, leaf chlorophyll content, and overall grain yield. Increasing potassium application led to taller plants and thicker stems, especially in one of the rice varieties. Both rice varieties showed an increase in grain yield with potassium application, with no significant difference between different levels of potassium.