Stationary Forestry Chipper for Olive Pruning Harvesting

Olive pruning could represent an important biomass resource for energy production considering that over 2600 Gg of dry matter represent the annual amount of biomass that could be obtained from olive groves just in Italy. Different experiences of pruning harvesting are reported in literature, especially related to shredders towed by tractors while limited knowledge is available on performance, quality of work and costs of harvesting logistics based on stationary chippers. The aim of the present paper is to analyze machine performance of a forestry stationary chipper applied to pruning harvesting for what concerning work productivity, quality of the comminuted product and harvesting operating costs. Although widely used in the forestry sector, the use of a stationary chipper for harvesting and comminuting olive tree pruning is poorly documented and therefore the study is innovative and fills a gap in the literature where little information is currently available. The results showed highest work productivity ever found in olive pruning harvesting systems and equal to 5.23±0.81 Mgdm h-1. This allowed also to obtain a little economic gain from a residue which is actually considered a problem for olive groves’ owners and not a potential source of income. According to preliminary data the use of a stationary chipper seemed very efficient in olive groves with big amount of pruning to be processed, and with big branches not harvestable by the most common towed pruning harvester. In addition, the collection system based on a stationary chipper does not require pre-harvest raking. This aspect represents an added benefit in terms of cost reduction for the farmer.