Towards Robot-Assisted Precision Irrigation: Proximal Soil Sensing & Physical Leaf Sampling in Orchards

Precision agriculture utilizes sensor networks to inform growers on optimal conditions for applying agronomic inputs (water, fertilizer, pesticides, etc.). Precision irrigation is a subset of precision agriculture that focuses on optimizing water usage. While some growers have embraced these techniques, their usage is far from universal due to cost and labor barriers. Several contemporary works have introduced robotic means for crop monitoring and harvesting. These autonomous systems typically use aerial means for sensing to cover broad regions of crops and ground-based rovers for harvesting. Yet, considerably less work has been performed on using ground-based systems to sample and perform direct measurements. Towards this purpose, two robots are designed and tested. The first robot for proximal soil sensing uses an ECa sensor to generate soil moisture maps of an orchard. The second robot for physical sampling uses a 6-DOF robotic arm to pick a leaf from an avocado tree for stem water potential analysis. These two systems present steps toward a larger robotic system for irrigation measurements in orchard crops