Due to the lack of the described practical examples of sunflower by-products harvesting by forage harvesters, the calculations are based on the experience of corn stalks harvesting, taking into account the peculiar properties of sunflower. Chopped sunflower residues are transported by a tractor with a trailer to a storage facility at a distance of up to 10 km.
Initial conditions: the duration of harvesting is 30 days, the duration of work is 8 hours/day, deductions for maintenance and repair is 5%, amortization is 10 years, the salary of the operator is 17.7 euros/day, the yield of sunflower: min. 1.5 t/ha, av. 2.5 t/ha, max. 5 t/ha; the volume of stalks for harvesting from 1 ha of a field: min. 1.6 t d.m./ha, av. 2.1 t d.m./ha, max. 3.0 t d.m./ha.
The results of the estimation of the net cost of the harvesting of sunflower residues for the three volumes of biomass collection per unit area are shown in Figure below. Amortization is the main component of costs.
Cost of sunflower stalks harvesting with a forage harvester
The results of the feasibility study of the chain on the basis of a self-propelled forage harvester are given in Table below. The payback period of crop by-products harvesting significantly depends on the volume of biomass harvested per hectare, which also affects the loading of equipment.
Thus, when harvesting sunflower by-products in the amount of 3 t d.m./ha, the simple payback period of the harvesting unit is 4.8 years. In the scenario of harvesting average biomass volumes of 2.1 t d.m., which can be achieved with a sunflower yield of 25 m.c./ha, the simple payback period of such a harvesting unit is 6.4 years. At the yield of sunflower by-products of 1.6 t d.m./ha, the simple payback period of the harvesting is 8.2 years.
Feasibility study of harvesting sunflower by-products with a forage harvester
* The cost includes direct costs for harvesting biomass and deductions for equipment amortization.
** The price is equal to the sale price of sunflower by-products (W25%) of 33.8 EUR/t without VAT.