Drones have come to America\'s farmlands, said Michigan State University researchers who unveiled an unmanned aerial vehicle to help farmers maximize yields. Farmers can now get a birds-eye view of their fields, in full high definition, for help in improving nitrogen and water management and reducing environmental impact such as nitrate leaching or nitrous oxide emissions, a university release reported Tuesday. The unmanned aerial vehicle, or UAV, can fly over a field, documenting the field\'s status down to inches to give farmers details on the current health of their crops, the researchers said. This can create the opportunity for spot treatments rather than unnecessary widespread ones, they said. \"When you have a cut and need disinfectant, you don\'t dive into a pool of medicine; you apply it only where you need it and in the quantity that is strictly necessary,\" MSU ecosystem scientist Bruno Basso said. \"Rather than covering the entire field with fertilizer, it can be applied exactly where it\'s needed. We basically try to do the right thing, at right place, at the right time.\" The drone carries three sensors: a high-resolution camera; a thermal camera, used to monitor plant temperature and hydration; and a laser scanner that measures individual plant height in centimeters. It can allow farmers to distinguish plants that need water or nitrogen, and treat those plants -- rather than the entire field -- immediately, the researchers said. \"The UAV is like an X-ray,\" Basso said. \"Before we can diagnose the problem, we need to collect as many details as possible.\" MSU is the second university in Michigan to get permission from the Federal Aviation Administration to fly agricultural drones, joining the University of Michigan, which obtain FAA approval last year.