Free Sentinel-2 imagery matches finer sensors for crop stress trends, Arkansas study finds

Ana Morales-Ona Smith, an extension soil fertility specialist at the University of Arkansas Division of Agriculture, tested four data sources for spotting crop stress and guiding fertiliser use: open satellite images, paid satellite products, drone flights and handheld sensors. She presented the work at the 2026 Rice and Soybean Field Day in Harrisburg.

Early results show the sources often pick up similar crop-response trends despite big differences in resolution. Free Sentinel-2 imagery has 10-metre pixels, a revisit of a few days and an archive reaching back to 2015, which can reveal persistent variability patterns within fields. Paired with soil and tissue sampling, it could target nutrient applications, for example nitrogen in rice.

Separately, Jason Davis and Terry Spurlock found that raising spray-drone speed from 30 to 40 mph cut fungicide coverage by about 20 per cent. Coverage does not necessarily equal disease control, and further trials will seek optimal settings.

Why it matters: Evidence that free Sentinel-2 data tracks crop variability about as well as pricier sources supports low-cost precision agriculture services. That is relevant for African growers and advisers without drones or commercial imagery budgets.