There's genuine wonder in Curt Shonk's voice when he says, "I'm really surprised more people don't apply anhydrous when they plant corn."
Nine years of experience have convinced this Breckenridge, MO, farmer that combining the trips saves time and money without threatening the crop.
"The best time to put down anhydrous is usually when the soil is ready to plant," he says. "If you try and put it on before then, soil is cold and wet, and you're always causing compaction. During the colder weather I also got a lot more variation in application rate with temperature fluctuations. And it's a lot faster to make one trip instead of two."
Shonk no-tills all his corn, except where tillage is needed to smooth fields. He usually plants one-third corn and two-thirds soybeans on 1,500 acres.
"Purdue University published data that showed as long as you stayed 5-6" away from the seed you wouldn't cause any damage. We've got the knives mounted on 60" centers on our planter and 15" is the closest we get to the seed."
Shonk mounted six anhydrous knives with coulters in front of his 12-row, 30" John Deere planter. The skip-row pattern splits every other row.
"The anhydrous moves out quite a bit, and the corn roots grow toward it. So when the plant needs the nitrogen, it's available," he says. "We've never seen any evidence of plant damage from direct contact with the anhydrous."
Before planting, Shonk broadcasts dry fertilizer, varying rates by soil tests.
"We broadcast from 140 to 200 lbs of N, depending on the field. Some fields get P and K, some don't."
At planting, Shonk knifes in 110-120 lbs of N, placing the anhydrous about 6" deep.
He says it takes more brain power and horsepower when planting anhydrous alongside corn seed.
"You have to think more about what you're doing. I'm always willing to work harder when I can save quite a bit of money. Anhydrous is a dangerous product, and you have to remember the safety rules whether you put it on ahead of or at planting."
Shonk pulls his planter-anhydrous applicator with a 160-hp two-wheel-drive tractor and admits he wouldn't want to try it with anything less.
"That's the minimum we can get by with and still plant at 6 mph," he says.