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Corn+Soybean Digest

Farming Data Fields

Most days, Bill Butler farms the same fields that his ancestor Bartholomeaus Theiss farmed in Sublette, IL.

But in his office, he has broken down 1,313 acres into 50 x 50-ft. square grids and 392,970 data fields. For nine years, he's used evolving GPS and precision agriculture technology to map which hybrid is planted where, which herbicides it receives when, which rates of DAP and nitrogen (N) it received, what it yielded, where his refuges are and how many nutrients each harvest removes by soil type. This geo-referencing is especially helpful in tracking his Roundup Ready acres and low-linolenic soybean acres.

His tool chest includes Panorama database, GPS mapping, Farm Trac, Farm Works and Farm Site software, an Ag Leader PF3000 Pro yield monitor, GPS 2000 and lightbar.

His database drives Farm Site to generate application maps used by his Ag Leader PF3000 Pro. His data is geo-referenced for fertility, seeding and harvest operations in the 2,500-sq.-ft. grids. “I use that size management cell because our fertilizer buggy spreads 50-ft. swaths,” Butler says. Farm Works maps the variety locations.

Butler pulls soil samples himself and loads the Excel spreadsheet results directly into his database without retyping. They link up with the samples' precise geo-coordinates. Then the data is loaded into Farm Works, which maps the results.

Database numbers drive Farm Site to create the application maps used by the Ag Leader PF3000 Pro yield monitor.

Information from his yield monitor prompted a major change in his crop rotations in 1988. As he crossed the line between first- and second-year corn, he witnessed a 100-bu. yield drop. “The monitor went from 130 right down to 30 when I crossed that line; it got my attention,” he says.

That drought year experience drove home his vulnerability to a single crop and the chance of income swings that seem to him more likely with corn-corn rotations.

“I've found that my income is a lot smoother with 50-50 corn-beans,” he says. “I may not hit a home run, but I get more guys home.” Switching to no-till beans in 1992 added significant cost savings in fuel and machinery expense to confirm that decision.

His custom-made dry and anhydrous ammonia applicator tailor blends anhydrous ammonia and DAP on the go. His software reconciles the nutrients removed at harvest, by cell, with soil-test results. It subtracts the N supplied by DAP and calculates how much N still needs to be applied as anhydrous ammonia. “After harvest, I can pull up a geo-coordinate to see by yield and fertilizer data what is working for me and what isn't,” Butler says.

His precision ag equipment led Butler to look further into his N rates. “A couple of years ago, we ran out of a dry mix of DAP and potash with one strip left to go. When I pulled up the yield maps, the strip that we missed did fine,” he says.

Still, Butler has stuck with 155 lbs. N/acre (plus the roughly 20 units N from the DAP). “That's a good 10-15 lbs. heavier than I really feel we need, but with corn prices where they are, I'm not going to short myself,” he says.

“I've been playing around with this for seven years, pushing N rates a little lower. The only way I've found to make a yield impact is to just shut the thing off,” Butler adds.

He designates 100 x 100-ft. patches of various fields to receive different N rates, and checks results at harvest.

“I've looked at the anhydrous ammonia rate plots for this year, and again, I don't have a yield drop where rates were lowered to 100 and 125 lbs. from 150 lbs.,” Butler says.

Information from his yield monitor will play a smaller role in hybrid selection this year than in years past, he says.

“My approach to hybrid selection has evolved over the years. I used to load dozens of yield plot data into my computer to help me choose a good hybrid. Lately, my thoughts have changed,” he says. “Genetics are pushing corn yields up by 2.4-3.4 bu./acre — this implies that a good three-year-old hybrid would be only a mediocre hybrid today. Hence, the need to stay on the cutting edge of hybrid release. The only way to do this is to trust your seed dealer and seed company, and go with a good mix of several of the latest new and one-year-old hybrids.”

HOW DOES BUTLER'S precision-ag technology contribute to the bottom line? Bruce Erickson, Purdue University certified professional agronomist and part of its Site Specific Management Center, sees it this way: “Precision information on the farm can be profitable if it drives a decision that results in increased crop yields or quality, decreases costs or reduces risk. The Butler farm has a considerable investment in precision technologies, and the returns to this have come in N fertilizer savings, deciding the most appropriate crop mix for their operation and in tracking specialty crops.”

Butler says that the main value of the information he's gathered is what he learns from his mistakes. “I've learned more from my mistakes than my successes,” he says. “From there, the yield monitor closes the management loop.”


  • Education: Mechanical engineer

  • Sixth-generation Lee County, IL, farmer

  • Acres: 1,313 acres total [643 acresof corn following beans; 300 acres of low-linolenic Roundup Ready beans with a 60¢ premium (2007); 280 acres non-GMO beans with a 70¢ premium (2007); and 90 acres standard Roundup Ready beans].

  • Tillage: Beans are no-till following corn. All corn is one cultivator pass before planting after soybean harvest. Anhydrous ammonia is knifed either in the fall or sidedressed for the corn.

  • Predominant soil types farmed: Tama-Muscatine association

  • Corn seeding rate: 31,500/acre

  • Bean seeding rate: 175,000/acre; final stand of 150,000-170,000

  • Affiliations: University of Illinois agronomy research advisory committee; University of Illinois DeKalb ResearchField Advisory Committee

  • Favorite source of new ideas: “I trust the methodology of the Universityof Illinois to test new ideas.”

  • Maximum return to nitrogen(N) investment: Butler can vary hisN rates by 32% on the go. “I am confident that we are still over-applying most ofthe time,” he says. “This corresponds tothe results from the Iowa State N ratecalculator for northern Illinois.”

    We have been putting out N rate comparisons for many years. I have yet to drop the rate low enough to suppress yields, meaning that my base rate has always been at least 10% higher than necessary,” Butler says.

  • Favorite management tools:
    1. Panorama database and Farm Works software. “The yield monitor reallycloses the management loop.”

    2. GPS mapping

    3. 2,500-sq.-ft. soil grids. “I've verified areas where my pH goes from 5.8 to 6.8 injust 230 ft.,” Butler says.

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