Influence of soil type on nutrients status of highbush blueberry leaves in Latvia

The aim of the present study was to find out the influence of peat and mineral soils on the leaf nutrient status of highbush blueberry in Latvia to reveal nutrient imbalances, as well as to determinate fertilization practices. Together 90 leaf samples from different blueberry producing plantings developed on peat and mineral soils were collected during 2013-2015 and the content of nutrients was determined (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, Mo, B). Overall, the chemical results revealed a high heterogeneity in leaf micronutrient concentrations for both types of substrate. The highest variation was found for Cu and Zn in blueberry leaves from peat soils, while for mineral soils the highest variability in leaves was found for Cu and Mn. In general, environmental conditions expressed a considerable influence on blueberry mineral nutrition. Significantly higher mean levels of Ca, Zn, Cu and B were found in blueberries in peat soils, while higher Mn was observed in mineral soils. The data showed that, according to current nutrient standards, 55 and 48% of total leaf nutrient concentrations were in optimum range for peat and mineral soils, respectively, thus suggesting that peat soil conditions could provide a better nutrient supply for highbush blueberries. The research revealed deficiency of N, P, Cu, Mo and B in the vast majority of leaf samples from both substrates. In addition, low levels of Fe were found for blueberries grown on peat soils, and low levels of Ca and Zn - in mineral soils. Since an optimal nutrient status of crop plants is very important to obtain high-quality yield, special attention should be paid to macronutrients as N and P, as well as micronutrient fertilization to avoid blueberry yield limitation.