Crop imagery identifies early problems

You’re harvesting corn, and a couple of rows on a regular pattern don’t look as good. The only way to pick it up on the monitor would be to run those rows separate. What caused it?

Maybe you applied starter fertilizer and those two rows didn’t get it due to plugged tubes. Odds of two tubes side by side plugging are low. Maybe one applicator knife on a sidedressing application plugged. That’s more plausible. Maybe it matches a wheel-track pattern, and those rows were compacted.

The point is that if you first see it from the combine cab, the trail is cold. It’s certainly too late to help yield this year.

Key Points

Agronomists still believe in using crop imagery to identify problem areas.

Some problems can be corrected if they are caught early enough.

Other discoveries will point toward needed adjustments for 2012.

Jason Webster offers an alternative. Use crop imagery during the growing season to pick up areas with different colors of vegetation. Then ground truth the areas that don’t look right. The imagery is tied to GPS. If you do it in June, you might still have a chance to correct the problem during the season if the cause turns out to be fertilizer related. If you find it in July or August, you know what you need to change next year.

Webster operates the Beck’s Hybrids Practical Research Farm outside Bloomington, Ill. When he talked about crop imagery at field days this fall, farmers flocked to his talk. It even took two trams instead of one to keep up with him every time he gave a talk at Beck’s popular field day at Atlanta.

See and believe

“We believe utilizing crop imagery can really help you manage crops better,” Webster says. Beck’s Hybrids can help customers arrange for aerial imagery at a set cost per acre. The results can be displayed either in color photos or infrared images.

Webster worked with farmers who saw unusual patterns in their fields after planes flew over and took aerial imagery. Sometimes the results were easier to explain than at other times. “We call it crop health imagery, because what we’re really looking at is biomass,” he says.

Less biomass tends to show up as yellow or brown colors in photos, especially later in the season. One farmer was puzzled when he saw a bright green strip instead of a dark green strip in one field.

“When we went to the spot, we found weeds. There was biomass, just not the right kind. He then recalled he had a sprayer problem while applying herbicides that accounted for the strip of weeds,” Webster says.

This summer, wind damage showed up in many images. Often the damage was deep in the heart of a big field, not visible from the road. It actually showed up best in infrared images, he says.

While you can’t fix wind damage, you can use the information to decide if you will need a corn reel at harvest, or if you should expect more disease and mark that field for early harvest.

“The whole idea is to identify areas where something is wrong and go find them,” he concludes.


Story board: Each image tells its own story of someone’s field, notes Jason Webster.

This article published in the October, 2011 edition of INDIANA PRAIRIE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2011.