Tag Archives: harvest

426-442 J. Jobbágy, K. Krištof, A. Schmidt, M. Križan and O. Urbanovičová
Evaluation of the mechanized harvest of grapes with regards to harvest losses and economical aspects
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Evaluation of the mechanized harvest of grapes with regards to harvest losses and economical aspects

J. Jobbágy, K. Krištof*, A. Schmidt, M. Križan and O. Urbanovičová

Slovak University of Agriculture in Nitra, Faculty of Engineering, Department of Machines and Production Biosystems, Tr.A. Hlinku 2, SK949 76 Nitra, Slovakia
*Correspondence: koloman.kristof@uniag.sk

Abstract:

The aim of the study was to evaluate the mechanized grape harvest conducted by the trailed harvester. As a criterions was introduced the performance, harvest losses of grapes and economic efficiency from the perspective of its introduction. The calculations consist of total annual and partial unit costs also with regards to indirect costs which are formed by the grape losses during the harvest. Evaluation was conducted on three varieties of grapes. The losses of grapes, total annual and partial unit costs were calculated for selected varieties of grapes and also for whole production area. The mean grape losses for whole production area were determined at 470 kg ha-1, while the greatest portion of these losses (9.7%) was observed in case of Neronet variety. Among other analysed aspect were the efficiency of mechanized harvest introduction by definition of labour costs and the ransom price of grapes in relation with minimum required area. A substantial part of total costs for area 100 ha was formed by direct costs up to 15.24% greater than the indirect costs. The efficiency of machinery introduction into the harvest process was observed at minimum area of 16.92 ha in case of rental mechanized harvest of grapes. In case of mechanized harvest conducted by previously bought trailed grape harvester the value of minimal efficiency was determined at 27.42 ha year-1. As a result then serves an effective utilization of mechanized grape harvest in selected company but it is not limited to it and can be applied on any other scenario.

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361-371 R. Pecenka and T. Hoffmann
Harvest technology for short rotation coppices and costs of harvest, transport and storage
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Harvest technology for short rotation coppices and costs of harvest, transport and storage

R. Pecenka* and T. Hoffmann

Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Max-Eyth-Allee
100, 14469 Potsdam, Germany;
*Correspondence: rpecenka@atb-potsdam.de

Abstract:

The lack of knowledge regarding cost-efficient design of whole production chains as
well as the availability of powerful harvest machinery are some of the main obstacles for
competitive production of bioenergy from short rotation coppices (SRC) at practice. In general,
two different harvest lines are available: the cut-and-chip and the cut-and-store lines. Whereas
the cut-and chip line provides wood chips which have to be stored until next heating season, the
product for intermediate storage of the cut-and-store line are whole trees. Both process lines have
major differences not only in harvesting, but also in transport, storage and process losses leading
to different costs of the end product wood chips. On basis of data from several SRC harvest
campaigns, production costs for wood chips have been calculated to identify best practice
solutions taking the following factors into account: chip size determined by the harvest system,
storage including related costs and losses, field size and shape as well as transport to storage.
According to the results, mower-chippers and forage harvesters can provide wood chips at lowest
production costs (43…45€ tdm-1) if field shape is favourable for harvest operations. Under less
favourable field conditions costs are approx. 7 to 14% higher. Highest production costs have to
be accepted if whole trees are harvested with a shoot harvester (64 to 72 € tdm-1). The reduction
in storage losses and storage costs are not sufficient to compensate higher machine costs for
harvest and additional comminution with mobile chippers from forestry

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151-160 R. Pecenka, D. Ehlert and H. Lenz
Efficient harvest lines for Short Rotation Coppices (SRC) in Agriculture and Agroforestry
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Efficient harvest lines for Short Rotation Coppices (SRC) in Agriculture and Agroforestry

R. Pecenka*, D. Ehlert and H. Lenz

Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Max-Eyth-Allee 100, 14469 Potsdam, Germany; *Correspondence: rpecenka@atb-potsdam.de

Abstract:

Wood from short rotation coppice (SRC) such as poplar, willow and black locust is a promising option for the sustainable production of biofuels and biomaterials. Provided that production technologies, logistic chains and end user structures are well designed in farmers’ regional structures, these cropping systems may provide a secure source of income. One of the key problems at present is the lack of knowledge and powerful harvest machinery at practice. Although a lot of machines were developed and tested during the last 30 years, only a few have exceeded the prototype stage. Analysing the process chain for SRC, chip lines seem to be most cost-efficient for harvest, and the modification of forage harvesters for SRC is a promising option. But the high machine weight of forage harvesters is a serious disadvantage due to the limited trafficability of harvest plots in winter. Furthermore, for economic operation of these expensive harvest systems cultivation areas of more than 300 ha are required. Therefore, ATB has developed a simple and low weight tractor-mounted mower-chipper for medium sized standard tractors (75–150 kW) together with the company JENZ (Germany). The chipper is designed for flexible harvest of wood from SRC and Agroforestry (max. stem diameter 15 cm). The total weight of the harvester (tractor and chipper) is less than 50% of the forage harvester combination resulting in much more flexible field operation and lower harvest costs. The machine has been successfully tested in the last two harvest seasons and is on the market available now.

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