“In precision ag, you might put the same total pounds of N on the fields but move it to get the best ROI,” Eller says. “On top-end producing soil types we see the highest nitrogen efficiency—I’ve been able to pull .5 lb. per bu. of corn while lower performing soils can take 1.5 lbs. to produce one bu.”
Work with an advisor to find out what the best prescriptions are for your fields—both seeding rate and fertilizer will be heavily influenced by the soil tests you create. “If this zone is pushing 300 bu. when we applied 200 lbs., we can look at that efficiency rate, but I know I’ve left some of that top-end yield out,” he says. “So, if we get 300 at 200 lbs., what happens at 250 lbs? We’re still playing with that.” Because it takes 100 years, according to Purdue, to create 1” of topsoil, you don’t need to take soil tests with sensor tools every year. Ellers asks his farmer customers to get soils on every field once, at $10 per acre—unless they’ve done major dirt work or have a field that floods frequently.