Exploitation of Olive Tree Prunings. Evaluation of an Integrated Harvesting Demonstration in Central Greece

The aim of the present paper is to evaluate the most extensive olive tree pruning (OTP) harvesting demonstration ever occurred in Greece. In Fthiotida region (NUTS 3, Central Greece), an integrated harvester/ shredder (FACMA COMBY TR 200) was used to harvest the local olive groves of Agios Konstantinos. The pruning value chain included: i) windrowing prunings in rows on the olive groves; ii) harvesting and shredding the prunings (leaves included) from the rows with the harvester; iii) discharging prunings on platforms and finally iv) transporting prunings to a storage site where the loads were weighted via a weighbridge. The harvesting demonstration lasted for 14 days where around 54 ha of olive groves were harvested that amounted to 232 wet tons of harvested prunings (25% w/w average moisture content). The harvesting cost resulted to 58 €/harvested dry ton of pruning and produced emissions calculated at 36 gCO2eq/kg of dry harvested pruning. Aim of the current paper is to evaluate the whole pruning value chain during the harvesting demonstration in terms of biomass productivity (tons of prunings per ha), performance of harvester (working times, fuel consumptions) and transportation of prunings (fuel consumptions) into nearby storage area. Furthermore, an economical evaluation of the whole demonstration is performed along with a cost-breakdown of the pruning logistics. The costs include cost of the harvester, fuel costs of the harvester and the transportation platforms, renting costs of tractors and platforms, and labor and driver costs. Finally, samples of harvested prunings were collected for key fuel properties analysis. Harvested olive prunings were analyzed in order to investigate their potential for energy use and examine how has the harvesting methodology influenced their fuel properties. The fuel characterization was performed by applying established standards and the results will be presented on the current paper