Onion harvesting 79 minutes → 35 minutes…Self-propelled harvester completes digging, sorting and collection in one pass

Onion harvesting is carried out by first cutting the stems and removing plastic mulch, then digging up the onions underground, spreading them in the field to dry for two to three days, and finally picking them up one by one. According to the Rural Development Administration, the mechanization rate for onion harvesting work remains only 31.4% (2023). If it rains during drying or temperatures rise sharply, marketability declines, and schedules are often delayed due to weather. In the field, demand has grown for technology that can handle everything from digging to collection with a single machine.

The Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) announced on October 28 that it had developed and commercialized a self-propelled onion harvester with Shinheung Industrial Co. through the “Field Agriculture Mechanization Promotion Technology Development Project.” This harvester moves on its own while digging onions, separating out foreign matter such as soil, and collecting the crop all at once. It uses a four-wheel-drive and four-wheel-steering system, and is tailored to domestic field conditions by allowing the digging depth to be changed according to ridge height and the sorting speed to be adjusted. In the final performance test, the working time per 10a (1,000㎡) was 34.6 minutes, about 56% shorter than the 79.4 minutes required by the conventional method of using a digger and a collector separately.
Unlike existing self-propelled harvesters, which are crawler types, this product is wheeled. Bang Byeong-ju, head of research at Shinheung Industrial Co., said, “The wheel type has high horsepower, so the engine is large and its speed and pushing power are good.” The explanation is that the wheeled type is superior in driving speed and power.

Another difference is the integration of the sorting process. Bang explained, “Previous products were insufficient in digging work, or there was no product that handled digging, sorting and collection all at once,” adding, “The sorting line clears quickly, and the working speed can also be made fast.” Kim Myung-wook, principal researcher at IPET who managed the project, said, “It received agricultural machinery test results from the Korea Agriculture Technology Promotion Agency, and its performance and sorting functions have been strengthened compared with existing products.”

High temperatures during the harvest season have also increased the need for self-propelled onion harvesters. Bang said, “In the past, because digging technology was inadequate, we only sorted and collected, and onions had to be dried after harvest, but when temperatures exceed 30 degrees, onions cook in the open field,” adding, “Now we dig them immediately, put them in bags, and move them to an indoor drying place.” He explained that more farms are moving onions immediately after digging instead of drying them in the field because of high temperatures.

Accordingly, the drying location has also moved from the field to the warehouse. After harvest, onions placed in sacks (bags) are moved to a warehouse, where air is drawn in with ventilators to provide airflow and preliminary drying is carried out at room temperature. After moisture is removed, they are stored in low-temperature storage facilities at around 0 degrees.

The harvester has been supplied to major production areas including North Gyeongsang, South Gyeongsang, South Jeolla, North Jeolla, South Chungcheong and Gangwon provinces. According to Shinheung Industrial Co., five units of the product applying all of this technology have been sold for a fee since 2025. Seventeen digging-work models have been supplied since 2023. During the research process, four patents were applied for and all were registered.

Shinheung Industrial Co. plans to expand distribution in connection with agricultural machinery rental programs and to continue improving performance and ease of use by reflecting feedback from the field. It is also pursuing development of next-generation field-crop harvesters incorporating autonomous driving technology.