A drone has joined the vehicle fleet at Michigan State University, which is using the pilotless airplane to find ways to help farmers increase their yields through better use of fertilizer and water.
The National Science Foundation is financing the research.
The East Lansing school says the information that the drone gathers also will help reduce the environmental effect of nitrate leaching and nitrous oxide emissions.
The university says the drone "measures how crops react to stress, such as drought, nutrients deficiency or pests." It says the plane can document a field's status "down to centimeters."
The drone has three censors - a high-resolution radiometer, a thermal camera to monitor plant temperature and hydration, and a laser scanner.