A top priority for many farmers today is monitoring crop temperatures, and to do that they need the right equipment.

Infrared cameras can detect heat and turn it into an image, but they are very large, bulky, and expensive.

Infrared sensors are cheaper, but they don't provide an image. This makes temperature monitoring difficult on medium to large farms.

Researchers at the University of Missouri and the USDA's Agricultural Research Service have now developed a new method that provides accurate visual crop temperature data at a much lower cost. The system combines a regular digital camera with a micro-infrared camera to provide temperature data and detailed images that provide farmers with a wealth of crop information.

"Monitoring crop temperatures with infrared cameras can be tricky because it's difficult to distinguish between plants and background elements such as soil or shadows," said Ken Sudduth, USDA agricultural engineer and associate professor of bioengineering in MU's College of Agriculture and Food.

"By augmenting the micro-infrared camera with a digital camera, we created a system that can check crop temperatures in an extremely detailed and accurate way." Sudduth developed the camera system in collaboration with Philip Drew, a graduate researcher who completed his master's degree at MU while working on the project.

The cameras produce two different images of the same area: a visually detailed photograph and an infrared image. This setup called the Multiband System for Crop Canopy Imaging, allows farmers to identify problem areas from digital camera images and analyze those areas with infrared images, mapping the infrared images to light intensity. Combined with algorithms that automatically filter out soil, shadows, and other non-plant presence in the image, the camera system will allow farmers to precisely irrigate their crops based on the specific needs of individual plants, maximizing yields and optimizing water use instead.

"Medium-sized farmers own large tracts of land, but they don't always have expensive monitoring equipment," Sudduth said. "Our systems can accurately monitor large areas. That's good for farmers who can be more profitable, and it's good for everyone who depends on the crop." Sudduth says the system needs more fine-tuning before it can be sold to farmers, and future iterations may combine it with drones for added versatility. The study, "Development of Multiband Sensors for Crop Temperature Measurement," Computers and Electronics in Agriculture was published. mU's Alan Thompson and John Sadler of the USDA's Agricultural Research Service were also involved in the study.