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Five years old poplar (Populus spp.) plantation represents an interesting model of productivity. The most attractive characteristics of this energy crop are the handling flexibility, the high yield of biomass per area unit and the good quality of the chips obtainable. The mechanical harvesting of five-years old poplar plantations requires the use of specialized forest machineries such as harvester, feller, forwarder and chipper. Usually, after felling, the working phases consist of extraction, stacking and chipping. Generally, the last one is carried out in a “static phase”, where the product is taken from staked logs by using a hydraulic arm having a gripper that feed the chipping machine. In order to introduce technological innovations for the medium rotation forestry harvesting, the Consiglio per la Ricerca e la sperimentazione in Agricoltura, Unità di ricerca per l’Ingegneria agraria (CRAING) of Monterotondo (Rome, Italy) has developed a five years poplar cutwindrower and a self-propelled chipper equipped with a pick up system. The prototype of cut-windrower is a semi-trailed machine powered by a 95 kW tractor (at least). It mounts a cutting system and a double pincer with variable positioning. During the cutting phase the plant is grasped by the double pincer which conveys and unloads the stem along the inter-row. The trees are placed parallel to the progress of the tractor, but oriented in the opposite direction. The biomass windrowed is then chipped in a dynamic phase directly from the inter row using the self-propelled chipper equipped with the pick-up head. In the first tests, the cut-windrower has reached an operative working capacity of 0.22 ha h-1, with an operative production of 44 t h-1. On the other hand, the self-propelled chipper has showed an operative working capacity equal to 0.18 ha h-1, and an operative production of 35 t h-1 about. Both machines have shown good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

Woody Biomasses (from agriculture and forestry activities) are among the most promising renewable energy sources. Current literature describes woody biomass feedstock supply chains supporting biofuels and utilities industries: the potentially productive land area overheads required for biomass production may results in a complex logistic within the whole chain. Its effective enhancement requires significant changes in the logistics environment of energy plants for sustainable energy production and the sequence-dependent procurement chains for biomasses furthermore complicate these changes. According to this, optimizing harvesting and supplying operations turns out to be strategic within the framework of the current energy policy. In this work we present a case study carried out monitoring 57 short rotation forestry (SRF) production sites placed in Emilia Romagna Region, Northern Italy, all supplying the harvested biomass to the same biomass power plant placed in the province of Ravenna (Italy). The overall average yield of these sites was 55 t/ha, the site surfaces ranged from 0.3 to 20 hectares and the distance from the power plant ranged between 8.2 to 102 km with one production site only within 10 km from the power plant. Harvest and transport costs were calculated according to two different harvesting scenarios: i) single phase harvesting (one cutting/chopping machine + tractors and trailers); ii) double phase harvesting (cutting/mowing machine followed after 80 days by chopping machine + tractors and trailers). Results show that, according to the first scenario, at increasing distances overall harvesting and transport costs ranged from 8.9 to 21.0 ± 1.3 􀀍/t (average ± standard deviation), while, with reference to the second scenario, they increased from 10.3 to 23.8 ± 1.5 􀀍/t with the transportation costs accounting from 16 to almost 70% of the total costs.

In the Italian environments, the rapeseed (Brassica napus L.) is subjected, at ripening, to a seed shattering causing significant losses that reduce the yield and increase the oilseed rape seedbank in the soil. Meteorological events and mechanical harvesting are the main factors affecting the extent of seed dispersal. Lacking the availability of works investigating the actual losses during the harvest at large scale, the Consiglio per la sperimentazione e la ricerca in agricoltura, Unità di ricerca per l’ingegneria agraria (CRA-ING) has conducted a study in order to determine the effective seed losses at on-farm scale. The amount of losses of two combine headers, traditional for wheat and specific for oilseed rape harvest, was compared. The rapeseed header had a hydraulic sliding cut-bar and two vertical electric blade on both sides in order to reduce the pulling and tearing action between the cut-off plants and those still standing. The seed losses were evaluated before and during the harvesting by using plastic trays placed on the ground within the crop rows. The trays were arranged in a layout allowing the estimation of the seed losses of three different sectors of the combine headers. The results have demonstrated that, at farm level, the use of a specific oilseed rape header adapted and optimized for the crop requirements allows to obtain a level of seed losses (0,97% of total production), below the values reported in literature. For rapeseed, the higher losses are localized at the final parts of the head, where the plants are strictly intertwined.

Agricultural residues represent an important source of biomass for energy. Among the available biomass suitable for energy and available in Italy, pruning represents about the 20% of the total. About 1.184 million of hectares are planted with olive trees; the pruning residues coming from these plantations represent a wide source of biomass at National level. The authors tested six commercial pruning harvesters to determine harvesting losses and product contamination when recovering pruning residues. All harvesters used a mechanical pick-up to collect the residues and a shredder to reduce them into chips. Three different pick-up settings were tested and namely: 1 cm above ground level, manufacturer’s specification and 3 cm above ground level. Ash content in the shredded material was taken as a measure of contamination: the uncontaminated branch material collected directly from the trees had a value of 3.5%, whereas in shredded residues varied between 4.5% and over 5.5%, for the shortest and the longest distance between the pick-up and the soil surface, respectively. Harvesting losses were slightly, but significantly, related to pick-up setting, and mainly depended on machine type. Both machines have shown a good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010). Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres) was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm); the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors) and size descriptors (area, perimeter, Feret diameters, eccentricity) was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process.