On a sunny afternoon in August, a dozen scientists and students watched as a drone equipped with high-tech sensors from NASA rose above Morven Farm – a research center at the University of Virginia. From 165 feet above it could measure the light and heat given off by plants below. Manuel Lerdau, a professor or environmental sciences and research director at Morven, says those measures reveal the health of crops.
“As a leaf gets stressed, the yellows that we can’t see – two different shades of yellow -- change in their relative abundance. You can detect water stress or temperature stress long before they see the plants wilt. By the time a plant wilts from water stress, it’s already pretty late.”
But the aerial sensors detect subtle changes before plants are in danger.
“If you can know three days, four days earlier – and that’s what the remote sensing tells us, then you can use targeted irrigation, using less water when you farm and also have healthier crops," Lerdau explains.
Which is why Jesse Barber, from NASA’s Goddard Lab, is here with a high-priced device that’s more sensitive than the human eye.
“Light comes in a spectrum. It goes from radio waves all the way up into visible and gamma rays and x-rays," he says. "Our eyes see between 400-ish and700-ish nanometers, whereas this equipment can go a little bit below visible to ultraviolet and up into the infrared.”
Also on the research team, Professor Karthik Dantu – a computer scientist and robotics expert from the University of Buffalo, assessing the accuracy of data from LIDAR, heat and light sensors.
“How can we improve sensing methods across scale? NASA is interested in their satellites in space but also supports these sorts of remote-sensing applications, and how can you combine them to get better estimates?”
Lerdau says this way of getting and analyzing data will allow farmers to practice what’s called precision agriculture.
“The farmer can track much closer than they are able to do now – apply fertilizer when they need it, irrigate when they need it and also looking at insect infestation, so knowing when to put to pesticides on a field -- not using them unnecessarily.”
The next step, he says, is to create a sensitive drone that’s cheap enough to share with farmers around the world. Lerdau and colleagues at NASA have already designed a hand-held device that’s easily produced for just 200 bucks. This team is comparing data from that equipment with what it learns using the drone valued at more than $100,000.
But this research is already attracting attention from – among others -- John Pierce with the Monacan Nation in Amherst County.
“We’re hoping to do some remote monitoring ourselves out on tribal land.We have parts of the landscape that we haven’t been out to on foot," he says. "It’s pretty rugged territory out on Bear Mountain and the surrounding Tobacco Row Mountains, so hopefully this will make it a lot easier to monitor ecological conditions and waterway conditions and things like that.”
In addition to saving money and improving the environment, this approach to farming could save time – allowing farmers to survey their crops in a matter of minutes.
