Tricia Braid

Nov 10, 2016  |  ICGA

BLOOMINGTON, Ill. – A soil temperature forecasting tool recently introduced by the Illinois Corn Growers Association on their website is being used to guide fall application of anhydrous ammonia, a fertilizer option that is important to corn farmers in most of the state.

IL Corn’s Green Means Go map, created with the technical expertise of and in partnership with a Champaign-based company called Agrible, came about in answer to corn farmers’ concerns about making the best decisions they can with regard to fertilizer application timing. It can be viewed on the IL Corn website at

“We heard from farmers that just telling them when not to apply anhydrous ammonia in the fall wasn’t very helpful,” explained Jeff Jarboe, ICGA President. “They wanted some guidance in planning their fall nitrogen application to make the best decision they can for their farm given economics, weather, and environmental needs.”

The Green Means Go map uses Agrible’s proprietary forecasting technology to give a green light to fall nitrogen application based on a 10-day expectation of soil temperature at the four-inch level at 10am being at 50 degrees or lower and trending downward. This coincides with University of Illinois recommendations and the expectations of the Illinois Nutrient Loss Reduction Strategy.

“Protecting water quality by reducing nutrient loss really needs to be top of mind for Illinois corn farmers,” said Jarboe. “The role fall N plays in water quality is described in the Nutrient Loss Reduction Strategy and so we really think that providing this type of forecasting and planning help is a valuable service to our members and all corn farmers. Additionally, the economics of corn farming right now really point toward reducing loss.”

“Agrible was founded on the idea that site-specific data, such as rainfall and soils, can help growers make better decisions for their acres,” said Mike Hirschi, Agrible Senior Sustainability Advisor. “We provide the best science available to farmers, so they can make the best possible decisions for their specific fields on nitrogen application timing, logistics planning, and field operations.”

The Green Means Go predictive map is indicating that Fall N application is okay to commence for this year across Illinois, north of IL Rte 16, starting November 12. This prediction is broad and based on county level data, and therefore should be considered directional rather than
prescriptive. For the best information, farmers should consider accessing farm-level data to pinpoint application timing that is best for their specific situation.

IL Corn recommends proper timing of Fall N as a component of a suite of best management practices that should be tailored to each farm’s unique situation. A nitrification inhibitor should also be used at the recommended rate.