With the Bt trait making corn stalks tougher and continuous corn creating more residue, some growers are shy to adopt no-till or strip-till corn. But if that’s the case, then they really need to visit with Kermit Allard of Cedar Falls, Iowa, who’s strip-tilling corn on 20-inch rows.

“We are the only farmers we know of in this area who are strip-tilling on 20-inch rows,” says Allard, who farms with his son, David.

Minimize Soil Disturbance

The key to strip-tilling corn on 20-inch rows is to limit the width and depth of the strips, Allard says. The Allards build strips for their corn ground that are 4 inches wide and 4 inches deep.

“You don’t need to go deep. You don’t need to go wide,” he says. “Four inches works. We found that tilling wide and deep defeats why we no-till instead of ridge-till.”

Managing residue in 20-inch rows when strip-tilling corn takes some doing, especially in continuous corn, Allard acknowledges. But they are dealing with it successfully.

“For our fertilizer application, we use a wavy coulter in front of a double-disc opener,” he says. “To clear residue from the seedbed, we use a single shark tooth row cleaner for each row.

“The Sunco residue managers work real well. We went to narrow gauge wheels on our planter to allow more room for corn residue.”

The Allards farm about 1,200 acres, almost all of it in a corn-soybean rotation. They strip-till for corn after soybeans in the fall or spring and they strip-till their small amount of continuous corn in the spring.

“We just no-till the soybeans into the corn stubble,” Allard says. “On some ground, we’ll grow 3 or 4 years of corn on corn to build the soil and to help control erosion.”

Switching To No-Till

This growing season marks their seventh year in no-till and their fifth year strip-tilling corn. From 1966 until 2003, Allard ridge-tilled on 36-inch rows.

“We went to 20-inch rows and no-till at the same time,” Allard says, adding that they switched to 20-inch rows to improve their yields on marginal ground. “We went to 20-inch rows for no-tilling both corn and soybeans with the same planter. By no-tilling, we didn’t need to hire a no-till drill for soybeans.

“Both corn and soybeans benefit from narrower rows. With improved plant spacing, we have had minimal fungal disease problems.”

In a good year, the Allards’ marginal corn ground yields 125 to 150 bushels per acre and their good ground produces 200 bushels per acre.

Making Equipment

The Allards built their strip-till rig and fertilizer cart. They also extensively modified a corn planter for 14 rows on 20-inch centers and turned an eight-row corn head that had 36-inch spacings into one with 14 rows on 20-inch spacings.

“I come up with a lot of ideas and David does the cutting and the grinding and the welding,” Allard says. “That’s how we do things. We’ve been farming together for 25 years.”

They use a 6-ton Montag hopper cart with air distribution for dry fertilizer. They pull the cart behind the strip-till rig they made from a corn planter. They blocked one of the eight rows in the distribution system and split the other seven outlets for the 14 rows on 20-inch spacings.

The type and amount of fertilizer they place in fall strips after soybean harvest for corn the next year depends on the soil test, Allard says. They will apply dry mono ammonium phosphate (11-55-0), along with potash, urea and SuperCal 98 pelletized lime.

“We do apply some nitrogen as starter, in addition to what we put in the strip,” Allard says. “We sidedress everything, both corn following beans and corn on corn.”

Allard offers simple advice for farmers considering strip-till on 20-inch rows.

“Be committed to it,” he says. “Don’t go halfway and give up.”