Most of us are skittish about selling much of our new crop until we have a good sense for how it will yield. Mike Emens of Frankfort, IN, has a leg up on most of us. He subscribes to a satellite photo imagery service that helps project his yields in August within 10% of the final yield.

“I have limited on-farm bin storage,” says Emens. “So forward marketing is important for me. Getting accurate yield figures in August is a real boon for my marketing.”

Infrared (IR) imagery helps make accurate yield projections by identifying the locations for in-field yield sampling that will most accurately predict the field's final yield, says Justin Welch, agronomist and technology manager for Co-Alliance LLP, Danville, IN, which provides Emens' imagery.

“The imagery guides you to an assortment of different yield areas, and provides the percentages these areas make up in the field, giving you a more precise estimated yield for the field,” says Welch. “Without the imagery, you might take your yield samples from all the best areas of the field, or maybe all the poorest areas. Neither gives you an accurate estimated yield.”

Marketing is just one reason Emens uses the imagery service. His main interests in it are to better monitor his corn and soybean crops during the growing season, and to fine-tune his hybrid selection and fertility program.

IR imagery measures plant chlorophyll differences to identify non-crop vegetation, such as weeds and crop stress. Stress can be caused by low soil fertility, insects and disease, weeds and too much or too little moisture. IR imagery can also detect stand uniformity problems as well as tillage and compaction problems.

Many of these factors aren't easily detected from the ground, but are easily seen in shades of red and green on the IR maps. Subtle patterns of compaction, for example, are almost impossible to see from the ground.

Emens no-tills all of his cropland and is careful to stay off it until it's fit to drive on, but the imagery still picks up where machinery traffic had been greater on the edges of the field and by the field entrance. “I also could see where the tile lines were from the imagery picking up differences in the vegetation,” says Emens.

Imagery is especially useful when it identifies problems during the growing season that growers can fix. It revealed a 10-acre area where Emens' corn wasn't keeping up. He quickly learned that the row starter had not turned on during planting, leaving the area short of nitrogen (N). He was able to sidedress anhydrous ammonia in that area to rescue it.