Arkansas research shows potassium improves cotton yield and fiber strength
New research from the Arkansas Agricultural Experiment Station highlights the importance of potassium in improving cotton yield and fiber quality. The study was conducted by researchers from the University of Arkansas Division of Agriculture.
Field trials carried out during the 2023 and 2024 growing seasons at three locations showed that potassium fertilization increased cotton yield by up to 70% in soils lacking this nutrient. However, no increase was observed where soil potassium levels were already sufficient.
The research was led by Gerson Drescher, assistant professor of soil fertility, with Maria Paula R. Prado as the first author. The study was published in the Soil Science Society of America Journal and Agronomy Journal. The findings confirm that potassium plays a key role in strengthening fiber quality, including elongation and strength, while also increasing lint turnout.
“The results emphasize that adequate potassium management is key to maximizing both cotton yield potential and fiber quality,” said Drescher. “The study also showed that lint turnout and quality are positively affected by potassium fertilization, with fiber elongation and strength being more strongly related to potassium availability than other lint quality parameters.”
Potassium supports important plant functions such as photosynthesis and water regulation. These processes directly influence fiber development and overall yield. Researchers noted that modern high-yield cotton varieties demand more nutrients, which has led to increasing potassium deficiency across the U.S. Cotton Belt.
The study supports the “build and maintain” fertilization approach. This strategy focuses on improving low soil nutrient levels and maintaining them over time. Current recommendations suggest applying 140 pounds of K2O per acre in very low potassium soils and 95 pounds in low potassium soils.
Researchers also evaluated plant tissue testing methods to monitor potassium levels. They found that petiole samples showed a stronger relationship with crop yield compared to leaf samples. They recommend season-long monitoring of both plant parts.
The findings provide growers with practical guidance to improve fertilizer programs and maximize cotton production. Ongoing research continues to explore how in-season potassium applications can help correct deficiencies and protect yield potential.