For corn growers, the decision of when and how much nitrogen fertilizer to apply is a perennial challenge.
For corn growers, the decision of when and how much nitrogen fertilizer to apply is a perennial challenge. Scientists at the University of Illinois have shown that nanosatellites known as CubeSats can detect nitrogen stress early in the season, potentially giving farmers a chance to plan in-season nitrogen fertilizer applications and alleviate nutrient stress for crops.
“Using this technology, we can possibly see the nitrogen stress early on, before tasseling. That means farmers won’t need to wait until the end of the season to see the impact of their nitrogen application decisions,” says Kaiyu Guan, assistant professor in the Department of Natural Resources and Environmental Sciences at the University of Illinois, and Blue Waters professor at the National Center for Supercomputing Applications. He is also principal investigator on a new study published in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing.
Being able to detect and address changes in crop nutrient status in real time is vitally important to avoid damage at critical periods and optimize yield. In general, existing satellite technology cannot achieve both high spatial resolution and high revisiting frequency (how often a given satellite comes back to the same spot above the Earth). Alternatively, drones can detect nutrient status in real time, but they usually can only cover local areas; thus, their utility is limited in scale.
CubeSats bridge the gap between existing satellite technology and drones. With more than 100 of the relatively tiny satellites currently in orbit, Guan says, “CubeSats from Planet get down to a 3-meter resolution and revisit the same location every few days. So, right now we can monitor crop nitrogen status in real time for a much broader area than drones.”
Image: Research from the University of Illinois shows CubeSats, also known as nanosatellites, can detect crop nitrogen stress early in the season, allowing farmers to take action in real time. (Credit: Planet Labs Inc.)