Did you place fertilizer for corn in the right place this spring?

If you no-till, and you didn’t place fertilizer three inches to the side and level with the seed, you might have missed the sweet spot.

Dwayne Beck, SDSU professor and manager of the Dakota Lakes Research Farm, Pierre, S.D., says last year he saw a 20 bushel per acre increase in yield with a 3 x 0 inch  placement compared to broadcasting.

"Where we have residue, roots don’t go down, they go sideways," he wrote in a recent South Dakota Corn publication called Emerge.

"You want some of the N where plants have preferential access to it early in the season.  N moves to roots with water," he wrote in an email to me. "Since the corn plant does not use much water early it is nice to have it close so it does not have to move far.  It needs to be far enough away to keep from injuring the plant (that can happen easily if an opener slips for instance).  We use 3 inches to the side to be safe at higher rates of N.

I thought roots went down.

"Roots prefer cool and moist with lots of oxygen (they need oxygen to function)," Beck re[plied. "When there is no residue, the surface soil is too hot and it is often too dry so the roots angle more sharply down.  In nature, the surface is where most of the nutrients are absorbed and where most of them are located.  The fibrous surface 6-inches of a prairie soil is very active.  It has moisture, roots, oxygen, and nutrients furnished by dead plant material, animal manures, etc."

Beck says in no-till, corn roots will go eventually go deeper, following macropores in the soil. "But early in the season "we want to feed the small root that is there,’ he says.

To get fertilizer 3 inches to the side of the seed in a no-till field, Beck says you need a fertilizer opener that also cuts the residue. 

"Ours are from an old JD 750 drill, but there are several options," he says.