Growing Media pH and Nutrient Concentrations for Fostering the Propagation and Production of Lingonberry (Vaccinium vitis-idaea L.)

The lingonberry (Vaccinium vitis-idaea L.), recognized for its nutritional value and adaptability to cold climates, faces cultivation challenges, particularly in soil pH and fertility optimization. In a greenhouse study, lingonberry transplants were grown in media with pH levels of 6.5 (3:1:1 PRO-MIX BX/peat moss/perlite) and 5.2 (2:1 peat moss/perlite). Seven months post-exposure to different media pH, various fertility treatments (NPK) were tested, including a control (0–0–0), a balanced 5–5–5 kg ha−1 rate, a standard 36–24–48 kg ha−1 rate, and both higher (up to 54–36–72 kg ha−1) and lower (down to 9–6–12 kg ha−1) rates, applied every three weeks for fifteen weeks across six replications with a standard micronutrient rate. Results showed that media pH significantly affected plant height and volume, with plants at pH 6.5 growing 27% taller and larger than plants at pH 5.2. Fertility levels influenced plant volume, peaking at a moderate fertility rate (18–12–24 kg ha−1) before declining at higher rates. Interactions between pH and fertility significantly impacted shoot biomass, where higher fertility rates (above 36–24–48 kg ha−1) had a more pronounced negative effect on shoot biomass at pH 6.5 compared to pH 5.2. Root dry biomass was consistently 1.2–2.3 times greater than shoot dry biomass and less influenced by the treatments. Shoot death rates increased sharply at fertility rates above 18–12–24 kg ha−1, peaking at 21–35%. Nitrogen concentration in shoots and roots increased with higher fertilizer rates, peaking at 1.74% in the 45–30–60 kg ha−1 treatment. Fertility treatments raised growing media’s electrical conductivity (EC, 1:20 ratio), with a maximum of 1.41 dS m−1 in the 54–36–72 kg ha−1 treatment, though pH remained unchanged. Growing media nitrate levels increased with higher N rates, while ammonium levels were unaffected. Shoot death rates rose significantly with higher nitrate concentrations, particularly above 17.5 mg L−1, but showed no link to ammonium levels. Lingonberries can survive and thrive across a wide range of pH levels. These results indicate that lingonberries are resilient and low maintenance, requiring modest nutrient levels, and excessive fertilization hampers their growth.