To help corn throughout the growing season, try to understand the water infiltration rate of the soil and adjust it as needed, Farm Journal field agronomist Ken Ferrie says in Episode 12 of Corn College TV Season 3.
"We drove this ring in the ground, about 3 ½", and we didn’t disturb the soil inside here, so we can see how the natural structure takes in water," Ferrie says. "Then we would take something like this over here, just some plastic wrap, and I’m going to add the equivalent of 1" of water to the cylinder. Then we’re going to slowly pull this (plastic) out of here, let that water kind of lay in place, and then we’re going to time it … How long does it take for this water to disappear?"
(Click here to order the Corn College TV Education Series on DVD.)
Performing this test reveals the infiltration rate in terms of inches per hour. The slower the water goes in, the more you might look at changing plant density. It’s also important to evaluate nitrogen intake as part of the process.
Soil surface structure can also be evaluated from year to year to evaluate the effectiveness of cover crops. A rain simulator can reveal soil with good aggregate structure: After a rate of 6" of rain per hour, good samples will retain about 80% of fine materials on top of a 2mm screen.
Click play to watch Episode 12 of Corn College TV Season 3: