Blueberry nutrition on upland soils.
Soil management for blueberries (Vaccinium) on non-lowland soils in the USA is reviewed. Most nutrient problems of blueberries can be avoided by keeping pH between 4 and 5. To choose soils that will stay in this pH range, soils should have an exchangeable calcium level below 20% and K levels < 250 lb/acre. High soil organic matter is also important; levels > 6% are preferred. Blueberries have shallow root systems and are sensitive to drought and waterlogging, so drainage and irrigation is essential for productivity. Irrigation water should not be chlorinated and may need to be acidified. Sulfur can be used to lower pH; however this may take up to a year to have effect. All of the soil should be treated with S, not just the strips where blueberries are planted. Non-leguminous cover crops are recommended and should be well fertilized with N. Symptoms of N, Mg and Fe nutritional problems are given. Leaf analysis is recommended to identify nutritional problems. Urea is normally the best N source for blueberries as they are nitrate sensitive. If pH is above 5, ammonium sulfate is recommended. Recommended N-rates, S-rates and tissue nutrient concn are given.