CHEMICAL CHARACTERISTICS OF THE SUBSTRATE FERTIGATION AND OLIVE GROWTH

Young self-rooted olive trees (cv "Maurino") were grown for 200 days in 3.5 litre containers containing a mixture of sand (50% v/v) and peat (25% v/v) and respectively 25% of 1) grape stalks and urban sludge; 2) poplar bark; 3) forest litter; 4) peat.

Each substrate received irrigation (de-ionized water, max 80 ppm) and fertilization treatments. The materials tested, as a part substitute for peat, induced significantly superior growth in treatment with water alone, showing that there is a relationship to the availability of macro and micro-elements decteded by chemical analysis. Fertilization levelled out the action of the various substrates with the exception of the one containing bark. In this regard it appears that attention should be paid to the relative proportions of inorganic nitrogen supplied and that, more generally, a specific nutritive supply is necessary for a specific substrate.

Finally the fertilizing treatment was able to substantially modify, in adition to the quantity of growth, the biomass partitioning between shoot and roots.