The study found that highbush blueberry plants grow better with ammonium nitrogen or a combination of ammonium and nitrate nitrogen compared to nitrate nitrogen alone. Plants receiving nitrate nitrogen had dark roots, while those with ammonium nitrogen had lighter roots. The nutrient levels in leaves and roots were different depending on the type of nitrogen applied. Plants with ammonium nitrogen had higher levels of nitrogen, phosphorus, and iron, but lower levels of potassium, calcium, magnesium, manganese, and aluminum. The pH of the water draining from plants with ammonium nitrogen decreased over time, while the pH from plants with nitrate nitrogen increased.