A new conversion kit from Kopper Kutter, LLC lets you use a cornhead to harvest crops like sorghum, sunflowers, millet, milo and more. The Alternate Rotary Rowcrop Option (ARRO) is designed to be retrofitted to existing, newer cornheads.

"Row crop headers designed for 30-in. and 36-in. soybeans haven't been updated much since the 1970?s and 80's," says agricultural engineer Alan VanNahmen, Farm Buddy Co. "Milo and sorghum growers have had to settle for rebuilding old heads at a cost of $3,000 to $5,000. The problem is those heads were designed low in front for cutting soybeans. They are undersized for today's combines. The ARRO kit cuts just below the gathering chain, near the tops of the heads."

The old design used a stationary knife with a star-shaped cutter with 5 sickle sections. The ARRO kit consists of two 9-in. diameter discs with 27 in. of cutting edge each. Gathering chains drive sprockets mounted to the back of the blades when the units are mounted in place.

Installation is relatively easy with any production cornhead that uses 550 roller chain. Simply tilt the cornheads upright for access to row units and remove trash knives, stalk rolls and stalk-roll shaft housing. With the kit, stalk guides are bolted in place of trash knives on some models and gear case cover plates bolted onto the front row of unit gear cases. Front deck plate spacers and chain tensioners are reinstalled and adjusted.

"It takes half an hour per row to convert the first time and less after that," he says. "The first time you have to drill pilot holes into the row unit frame and ream them out for the mounting bolts."

Once installed, the discs rotate slightly against each other with a scissors action as the stalks feed into them. A shim package is provided to adjust as needed.

"We use good steel and have yet to do any resharpening with the units we've been using," says VanNahmen.

The kits sell for $950 per row. While a grower could wait until corn harvest is complete before converting for other crops, VanNahmen suggests buying a used head.

"You can pick up a 3 to 4-year old head with worn stalk rolls and deck plates and possibly chain," he says. "Replace the chains and install the kits, and you have a header for sorghum, milo and other crops."

VanNahmen, Kyle Kopper of Kopper Family Farms, and Randy Burns of Custom Harvester developed the ARRO system. Kopper wanted lower machinery costs and better residue management with his corn, wheat and milo rotation. Burns was frustrated with high maintenance costs and poor performance of existing row crop headers. VanNahmen was searching for a better way to harvest cornstalks and other crops for cellulosic ethanol production. He was using a Glenvar Bale Direct system to collect leaves and cob residue, but wanted to capture more corn stalks.

"I tried different corn heads, including pulling deck plates in tight, but none gave a clean cut," he says. "With ARRO units in place, I leave only 12 in. of corn stubble and 12 to 14 in. of sorghum stubble behind."