Assessing potassium fertilization in blueberry production in the southeastern USA

Blueberry plants thrive in soil with pH values of 4.5-5.5. The coastal plains of Georgia have sandy soils with low pH, low cation exchange capacity (CEC), and high potassium leaching rates.
Continuous use of fertilizers reduces soil pH and limits plant availability for nutrient uptake, leading to nutrient deficiencies.
Adjusting fertilizer applications to the plant’s physiological demands is essential to manage crop nutrition effectively and avoid over-fertilization.
This research project aimed to determine the relationship between potassium (K⁺) in the soil, leaf, and blueberry yield under different fertilizer regimes.
Soil and leaf samples were collected from experimental plots on three commercial farms from April to November 2022. The laboratory results indicated no correlation between soil potassium and leaf potassium concentration.
Leaf potassium levels were also significantly higher at temperatures below 15°C, suggesting the role of K⁺ in cold stress adaptation.
The farm with the highest fruit yield did not have higher soil potassium concentrations than the other farms, but it had the highest leaf potassium levels.
These findings suggest that reducing soil fertilization levels for blueberries may be possible without compromising yield and leaf potassium levels.

XIII International Vaccinium Symposium

Z. Rubio Ames, N. Espinoza, J. Lessl, Z. Williams

cold stress, southern highbush, rabbiteye, leaf nutrient, soil nutrient

https://doi.org/10.17660/ActaHortic.2025.1440.69