Sam Peterson

Northfield area farmer Sam Peterson used funding from a Minnesota Corn Growers Association grant to test which of three different programs could help him increase yields while reducing over seeding and over fertilizing. (Photo courtesy of the Minnesota Corn Growers Association)

Sam Peterson’s farm in Northfield includes a variety of soil types, with sand, loam and clay all represented on his acres.

This soil diversity makes Peterson’s farm the perfect place to test variable rate technology (VRT)—a suite of precision agriculture tools that help farmers better manage seed and fertilizer inputs by only utilizing what is needed for each particular part of a field.

Peterson’s proposal to test each VRT program was accepted through the Minnesota Corn Innovation Grant Program, which funds farmer-led research. With support from the Innovation Grant Program, Peterson set out to determine which VRT program works best on different soils, and how each VRT program can adapt to precipitation and ambient air temperature.

Ultimately, the goal of the Innovation Grant funding is to show that the most efficient VRT technology will result in farm profits as well as increased nitrogen use efficiency and thus reduced loss to the environment. Peterson compared three services — NitrateNow, Encirca and Field Forecasting Tool— to see which resulted in the highest yield while producing the most profit through improved efficiency.

Peterson quickly learned each VRT option uses its own process. NitrateNow takes a 12-inch soil sample to get nitrate levels, Encirca combines soil sample data with weather history, drainage and more, and the Field Forecasting tool uses a plant tissue sample.

Peterson is now bringing in his third harvest of crops raised with fertilizer rate recommendations supplied by the three services. Now it’s going to take some time to crunch the numbers and data gathered over the last three years on which has been the most effective.

During what was a wet spring, the nitrogen rate advised by each VRT varied, with Encirca coming up considerably higher than the other two in 2019. While the added nitrogen may prove helpful during what was less-than-ideal planting conditions, Peterson looks forward to getting the full economic impact.

“Fertilizer is not cheap, so I am also trying to look at the economics of it. That’s what farmers really want to know. Bottomline, is this going to pay? So, I am going to talk about it in dollars and cents, rather than this yield is better than that, because that’s not really a true comparison.”

The results of Peterson’s project and others in the Innovation Grant Project will be posted in early 2020 at

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