Department of Biosystems Machinery Engineering, College of Agriculture and Life Sciences, Chungnam National University / Department of Agricultural and Industrial Engineering, Hajee Mohammad Danesh Science and Technology University
Laboratory of Agricultural Machinery and Production Systems Design, Division of Bioproduction Environmental Sciences, Department of Agro–environmental Sciences, Faculty of Agriculture, Kyushu University
九州大学大学院農学研究院環境農学専攻生産環境科学講座農業生産システム設計学分野
Laboratory of Agricultural Machinery and Production Systems Design, Division of Bioproduction Environmental Sciences, Department of Agro–environmental Sciences, Faculty of Agriculture, Kyushu University
九州大学大学院農学研究院環境農学専攻生産環境科学講座農業生産システム設計学分野
Precision agriculture has been implemented in various cultivation operations for various crops. Recently, autonomous mower tractor with variable rate fertilization has been tried. Variable rate fertilization requires quantification of grass growth level. Objective of this study was to compare the performance of potential sensors under different growth levels and sensor operation conditions. A CCD camera, an ultrasonic module, and an optical reflectance sensor (i.e., Crop Circle) were tested at fields with different grass growth levels. Effects of sensor mounting height and angle were investigated. Effects of vehicle (i.e., mower tractor) vibration and traveling were also investigated: under static, vibration and no traveling, and vibration with traveling conditions. Results showed that sensor mounting height had a little effect on the sensor performance, and grass growth level was successfully quantified. Camera angle of 90° showed the best performance with less noise. The ultrasonic sensor could work with less deviation under static condition, whereas, CCD camera proved the applicability under all operating conditions. Operation condition of the optical reflectance sensor showed a little effect on the grass growth detection results. This study would provide information useful for automated grass growth mapping and variable fertilization recommendation.