Images from space could mean more profit for farmers

If a picture is traditionally "worth a thousand words," Dan Long is upping the ante.

Long, a soil scientist at the Northern Agricultural Research Center near Havre, is working with growers in different parts of Montana to show how images taken by satellite and aircraft can be used to add value to wheat.

In 1999, Long noticed that the wheat surrounding a dryland fertilizer experimental wheat field at Malta was lighter green than the experimental field. Since rainfall had been above normal, he suspected that the light-green crop lacked nitrogen.

As an experiment, he added late-season fertilizer to one of the light-green fields to see if he could increase the crop’s nitrogen status and thereby its final grain yield and quality. The extra nitrogen added 1.5 percent protein and a small yield increase that together added $6 to $10 profit per acre based on 1999 prices .

"We might not have noticed except that we had the darker experimental field as a comparison," said Long.

So how could farmers learn about the nitrogen status of wheat if they weren’t lucky enough to have nitrogen fertilizer experimental fields nearby? Long said he thought satellite imagery might be able to pinpoint such problems. And such imagery would be labor-conserving compared to taking leaf or soil samples from multiple places in the field. An early warning of inadequate nitrogen can be especially valuable where there is more precipitation than expected, such as in Northeastern Montana in the past few years.

Mike Lang, owner of Northern Ag Service in Malta, says he thinks Long’s research will yield "good practical information" and "has a future of being used by the farmers. We’re . . . making trips over these fields anyway. It would be real practical to add additional nitrogen when we spray for weeds."

With a new grant, in 2002 Long was able to continue the work started in 1999. He now heads a five-state effort to refine the information gathered from satellite images, working to make more useful information available to producers and thereby make the images more profitable. The focus of the work is to determine whether remote sensing can be used with terrain modeling to better predict crop yield or quality response to late-season nitrogen.

For the project in Montana, hard-red wheat is the target crop. In South Dakota, the focus is sugar beet, while it is corn in Minnesota and cotton in Georgia.

"Proper nitrogen management is critical for high yields while maintaining quality, especially in terms of protein in hard red wheat and high recoverable sucrose in sugar beets," says Long.

In 2002, the researchers grew these crops under three conditions to be able to see the differences nitrogen status would make in a satellite image. One part of the field was a "check" strip with no added nitrogen. The test also included an intermediate amount and a "luxury" amount of nitrogen. They correlated satellite images of the field with crop measurements from the ground. With these as references, the researchers will be able to relate crop nitrogen status to spectral information in the imagery. The purpose, says Long, is to develop practical ways for growers to use images to predict crop nitrogen status.

In 2002, the Montana work was undertaken with the help of wheat growers Tom McClay near Lolo, Karl Mavencamp near Malta, and Gary Arnst near Valier. Several other Montana researchers are involved and include Denbigh Starkey, Rick Engel, Mal Westcott, Jeff Jacobsen, Van Shelhamer, and Christine Sommers Austin of MSU-Bozeman. Scientists in the other states include Paul Gessler of the University of Idaho, Craig Kvien of University of Georgia, Dan Humburg and Mary O’Neill of South Dakota State University, and Pierre Robert of University of Minnesota. This group of scientists coordinates its efforts mainly by email, monthly teleconferences, and annual face-to-face meetings.

The five-state team is using satellite imagery purchased through NASA from the two commercial space firms: Space Imaging, Inc. and Digital Globe. In addition, the research group is partnering with Resouce21, a private company based in Denver, Colo. that wishes to develop commercial uses for satellite imagery in agriculture.

"Resource21 is providing the research team with imagery in exchange for ground information on how well the imagery works for various agricultural applications," said Long.

Since field-wide additional fertilizer was profitable in 1999, site-specific application of fertilizer may yield additional savings. By applying farm inputs only where they are likely to be used by the crop and reducing applications on less productive ground, producers may be able to increase profits while reducing the potential of the run-off of unused inputs into nearby waters. Site-specific techniques rely on a variety of remote sensing tools, from simple aerial photos to satellite images. These images are converted to computerized maps interpreted by computers in tractors and combines. The computer then signals the machinery to change the amount of fertilizer applied based on what the crop can use.

The group is also working to develop an Internet-based 3-D visualization tool that will help ag-producers and other users of geospatial data interpret and analyze complex maps and images.

"We’re incorporating recent advances in high-speed computer graphics and 3-D visualization to take our complex spatial data and make it more intuitive. Such an approach may be used to help train producers in the technology, and it could also be appropriate for students from kindergarten to college," said Long. "They’ll be able to view a landscape dynamically from any perspective and explore data for meaningful patterns and relationships."

By basing the 3-D system on the Internet, Long says the amount and quality of information exchanged between the research, education and agricultural communities would improve. This would lead to a broadening of accessibility among growers and other professionals in different states who wish to increase their interaction.

Dan Long (406) 265-6115, Mike Lang (800) 243-4263

http://www.montana.edu/commserv/csnews/nwview.php?article=668