Browsing by Subject "Chaff"

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Ökonomische Bewertung der „Doppelernte“ von Getreidekörnern mit den Reststoffen Spreu und Stroh
(2021) Ortmaier, Jörg; Köller, Karlheinz
Objective of this work is an economic evaluation of new harvesting methods, so-called “dual- harvesting” methods for common harvesting of grains and their residual biomass. In detail, the aim is on the one hand to evaluate the predicted higher quality and quantity per hectare of har-vestable residual biomass such as chaff and straw that can be realized with dual-harvesting technologies, but on the other hand especially their additional income contrasted to the pro-cess costs by proceeding dual-harvesting. For this purpose, combine harvesting with additional chaff or straw harvesting is compared to some dual-harvesting methods, both in terms of process technology and in monetary terms. Dual-harvesting methods are simulated with self-propelled forage harvester threshing, forage wagon windrow harvesting, compact harvesting and harvesting with a tractor mounted stripper header. The comparison includes the required logistic-chains and crop aftertreatment, i.e. sta-tionary separation of grain and biomass for each method. As basis for calculations is done specific modeling, e.g. for chaff yields and crop volumes as a function of grain yield. Parame-ters such as area size are included and also field distance, loss times, e.g. for turning opera-tions in the field, working speeds and road transport speeds. A calculation model developed for this purpose calculates time required for harvesting of one field for all processes with the greatest possible comparability. Based on machine costs stored in databases, e.g. for depreci-ation or wear and repair, which are automatically transferred to their desired process calcula-tion via selection lists, the costs per operating hour and, including area per hour and area size, costs per hectare can be determined for each harvesting process. Since all processes have different levels of grain and biomass losses, the process-specific, total revenues for grain and biomass are calculated accordingly and process costs calculated in each case are deducted from them. The resulting harvest cost free outputs (HCFO) are used as a comparative value. Without taking into account costs of reproducing soil organic matter as long term result, the following HCFO result for the individual methods according to the assumptions are calculated: combine threshing with bale harvesting 1309.93 €/ha; compact harvesting 1285.66 to 1529.53 €/ha depending on the amount of straw harvested; forage harvester threshing 1421.04 €/ha; forage wagon swath harvesting 1429.40 €/ha; tractor-mounted stripper header 1279.58 €/ha. The compact harvesting method thus has an advantage of up to 219.60 €/ha over the estab-lished combine and bale technology with same given assumptions. The other methods are in between or slightly below the combine harvesting. If costs for nutrient removal and soil organic matter reproduction are included for long term perspective, the advantage of compact harvest-ing is up to 143.44 €/ha. Based on literature research and model calculations, it can be assumed with a high degree of probability that dual-harvesting methods actually make residual materials usable in greater quantities with higher quality than it is possible with widely used combine harvesting. Concerns expressed by Buchmann (1961) and Garmasch (1960) regarding the suitability of combine harvesting for an efficient provision of chaff and straw are substantiated when calculation re-sults are taken into account. In addition, agronomic effects of dual-harvesting methods are positive compared to combine harvesting, which was not able to be evaluated in monetary terms and therefore represents a great need for future research. The positive assessment is due to improved field hygiene by removing weed seeds and plant pathogens from the field during dual-harvest. This could re-duce the need for chemical pesticides. Use of cereal residues not only improves resource effi-ciency and "saves" land for cultivation of renewable raw materials, but the carbon contained in chaff and straw remains bound in sustainable products to a greater extent, such as in biochar. Dual-harvesting is an essential tool for cost-effective provision of plant residues required for that purpose and at the same time offers great potential for more environmentally friendly field management and benefits for biodiversity, e.g. through possibility of regular cultivation of plant mixtures instead of individual crops. Digital development up to autonomous field management can be made more rational in dual-harvesting methods through simplified processes in the field, which can be expected to lead to further increases in efficiency of grain and residue har-vesting in the future.