Robotic Lawnmower Saves Labor and Operation Costs in a Pear (Pyrus pyrifolia) Orchard

Abstract

There has been an increased interest and potential demand for agricultural robots in recent years to help reduce labor and operation costs. Therefore, the performance of a robotic lawnmower for weed management in a pear (Pyrus pyrifolia) orchard was investigated at the Center for International Field Agriculture Research & Education (CIFARE) of Ibaraki University, Japan, in 2018–2019. It was found that the average weed height was lower in the robotic lawnmower-managed plot (35–87 mm) than that in the riding mower-managed plot (approximately 15–281 mm) throughout the cropping period (from flowering to harvesting). The robotic lawnmower was superior to the riding mower, brush cutter, and walk-behind mower in terms of energy consumption (6 vs. 13, 56, and 18 kWh 1000 m^–2 month^–1), costs (133 vs. 206, 1122, and 277 JPY 1000 m^–2 month^–1), CO₂ emissions (3 vs. 3.4, 14, and 4.5 kg 1000 m^–2 month^–1), and labor requirements (28 vs. 40, 604, and 62 min 1000 m^–2 month^–1). Because the robotic lawnmower can be used without manual operation, it reduces the human workload (in terms of the increased ratio of the heart rate (IRHR)) in comparison with operating a riding mower (IRHR: 1.2), brush cutter (IRHR: 1.5), and walk-behind mower (IRHR: 1.4). Therefore, given that the average age of the population is higher in Japan than elsewhere in the world and this trend is continuing to increase, the use of robotic lawnmowers can be useful for weed management in orchards.