RADCLIFFE, Iowa -Denny Friest said this is the 10th year he's worked with the Iowa Soybean Association's On-Farm Network, which focuses on precision agriculture tools and technology to collect information that can increase his profits from crop production. He shared his experiences with farmers from the Mississippi Delta who visited his farm as part of the Iowa-Mississippi Farm to Farmer Exchange.
"We're looking at nitrogen management," Friest said. "We're trying to cut rates of nitrogen. It's an environmental and economic issue. We're establishing how low we can go."
Friest and his wife, Helen, and their son Brent, and his wife, Colette, farm together raising 1,450 acres of corn, soybeans and alfalfa. They have a 275-sow farrow to finish operation and also finish 5,000 pigs per year.
In working with the On-Farm Network, Friest uses GPS and a yield monitor to collect data from his fields. The trials he runs are made up of replicated strips marked with GPS. The strips compare normal practice with an alternative practice.
Friest uses hog and chicken manure, but also purchases nitrogen. Through his strip trials, he's learning that manure needs to be managed differently than commercial nitrogen.
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"The biggest thing we see is that in wet springs, the nitrogen from manure is already nitrate and it's much more susceptible to filtering through the soil and running off in the drainage water," Friest said. "It's not available for the plant to use. In a dry spring, we maintain a lot more nitrogen from manure. We have learned to look year to year and field to field. You can't just say that you need a blanket amount of nitrogen. You have to manage it."
Tracy Blackmer, On-Farm Network research director, said Friest spreads manure over his crop acres by putting it on the ground that needs it. Fields get manure one out of four years.
The Iowa Soybean Association gave everyone on the tour the opportunity for an aerial view of Friest's nitrogen plots via a helicopter ride. Strips that were short of nitrogen were visibly yellow.
Friest put down manure at a rate considered adequate last fall. In some plots, he sidedressed an additional 50 pounds of nitrogen this summer. The strips receiving the sidedressed N showed a response to the extra nitrogen. Trials from past wet years showed a yield response.
"What we thought was adequate was depriving the field of potential yield," Friest said. "Three thousand gallons of manure was supposed to have 150 to 175 pounds of nitrogen, but we needed more nitrogen for the corn to perform where it should be."
In dry years, a lower amount of nitrogen is sufficient. At the end of the season, Friest conducts a corn stalk nitrate test to see if the crop had enough nitrogen.
Precision agriculture tools help in his plot work with the On-Farm Network.
"I'm receiving a return on my investment by using the data I get from the strip trials to make decisions that reduce input costs," he said.
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The On-Farm Network started in 2001 and now operates in all Iowa counties, Friest said. It is working with farmers in Maryland and Pennsylvania and starting programs in Minnesota, Indiana, Illinois, Ohio and Missouri. He urged Mississippi farmers to get involved.
"I can pick out any practice I want to look at from nitrogen and phosphorus management to tillage and fungicides," Friest said. "They will help me analyze the data as long as I follow the protocols and collect the data."
