FURTHER INVESTIGATIONS INTO THE MINERAL UPTAKE OF HAZELNUT ORCHARDS

Mineral uptakes by the hazelnut have rarely been studied. In order to determine the quantity of mineral nutrients to be applied to the hazelnut orchard per year, we need to know the quantity of mineral nutrients the bushes consume over this period. With this goal in mind, investigation aimed at determining mineral extraction by hazelnuts was conducted in order to give a direction to future technical indications. In two hazelnut orchards in the specialised district of production in Piedmont (the Langhe) consisting of 20-year-old plants grown in bushed vase, the following were recorded for each plant: total yield, pruned vegetative mass, leaf mass and fruit husk which fell to the ground. For each of these, the content percentage of N, K, P, Ca, Mg, Fe, Mn, Cu, Zn and B were determined and then calculated as a proportion of dried mass per bush. The data reveal some differences as to mineral extraction, related to the site of the plantation. They also reveal the ‘frugal’ nature of the species, which extracts limited quantities of N and K, and even less P. Of the micronutrients, the highest extraction was for Fe, Mn and Zn.