Economic analysis of plow-type and conveyor-type sweet potato harvesters: A comparison of purchase and rental methods

Harvesters used for harvesting operating in Korean sweet potato farms are generally classified into plow-type and conveyor-type.Advantages and disadvantages of each harvester type depending on the operating methods are identified, leading to differences in farm income.Therefore, this study conducted an economic analysis of plow-type and conveyor-type sweet potato harvesters under both purchase and rental methods.For this purpose, work capacity was measured, and cost analysis was conducted for each case of purchasing and renting each harvester.Field experiment was conducted on an actual sweet potato farm to measure work capacity, digging damage rate, and digging loss rate.The work capacity of rental harvesters was assumed to be equivalent to that of purchased ones.Cost analysis was conducted based on the machine cost analysis method proposed by the Kuratorium fr Waldarbeit und Forsttechnik e.V. (KWF), which sums hourly fixed and variable costs.Results showed that the plow-type harvester had higher work capacity, whereas the conveyor-type harvester showed superior digging performance in terms of lower digging damage rate.Meanwhile, there was no significant difference in digging loss rate.In terms of cost analysis, the rental method using the conveyor-type harvester resulted in the lowest total cost at 12,950 KRW10 -1 a -1 .This is because the plow-type harvester has higher work capacity than the conveyor-type harvester, and the removal of fixed costs such as depreciation and maintenance when using the rental method.Therefore, harvesting operations using a rental plow-type harvester can contribute to reducing the total cost compared to other methods.