دانلود رایگان مقاله انگلیسی تکنولوژی های خلاق و متداول برای هرس محصول: یک بررسی - الزویر 2017

abstract

Pruning residues can provide a significant amount of biomass despite being rarely used as a renewable sources to replace fossil fuels. Exploiting such residues entails creating a sustainable and cost-effective supply chain in which the harvesting and initial processing of the residues play a crucial role. The study is a detailed and accurate survey of the harvesting technologies available in Europe for harvest pruning. After defining the main harvest technologies and the distribution of manufacturers in Europe, the survey details the main groups of implements: shredders, chippers and balers. For each group, the most important configurations are discussed, together with the main characteristics of the machine. Some of the main innovations are detailed (modular machines, non-stop balers, densification of the biomass) which can improve the quality of the product and the economic sustainability of the chain.

6. Conclusions

The collection phase has a pivotal role in ensuring the profitability of pruning recovery and use. One specific type of machinery or solution does not exist, and currently-used machines do no match all types of field conditions. The choice of the best technology should be made on a case-by-case basis because the economic viability of recovering orchard prunings depends on how the costs of the residue are managed as well as on how the benefits are redistributed between orchard owners, harvesting contractors and biomass users.

However, harvesting is only one component upstream of the more complex chain of logistics, a process also involving transport, storage, handling and pretreatment. In logistics and supply chain management, optimization is a key issue, in order to reduce transport costs and lower carbon emissions generated by the machines. This entails analyzing factors such as the amount of pruning potentially available, the selection of the best harvesting method, the location of the energy plants, transport and pre-treatment, and a route optimization analysis. Traceability could also be added to this list, which is a key issue for the food sector, but still lacking in the biomass chain.

Although just one aspect of the overall process, harvesting prunings plays a pivotal role in building a sustainable and profitable collateral production and hence it needs to be define correctly. Various successful examples of well-designed pruning supply chains for energy production are already available in Italy. For instance, Fiusis s. r.l. (Calimera, LE, Apulia) use olive prunings produced by nine municipalities around the 1 MWe cogeneration plant which produces electricity (which is then sold on to the national grid) and heat. Fiusis's well-established harvesting solution entails the use of three Facma harvesters (Comby model) for use on farms that have up to 400 olive trees [64]. For farms with a higher number of olive trees, prunings are collected at the edges of the fields and chipped with a stationary shredder, a Caravaggi, with a production capacity of 10 t h
1 [64]. Chipping in both cases is carried out after a 25e30 day period in which the prunings are left in the field to ensure drying and leaf shedding [64].