That’s why many no-tillers aren’t about to sell any of their valuable crop residues to ethanol plants — even if the price climbs to over $100 per ton. Once they do the math, they’ll recognize that losing the many benefits of residue is a losing proposition.

Since research indicates farmers who moldboard plow need to retain 3.4 tons of stalks per acre and no-tillers only need 2.3 tons of residue per acre to protect the soil, you’d think no-tillers would want to sell excess residue. Instead, no-tillers have always resisted the urge to remove residue.

Big Dollar Savings

Here’s our analysis for what a central Iowa no-tiller could lose by harvesting and selling only 1 ton per acre of corn residue to an ethanol producer:

The value of lost soil will be $4.93 per dry ton of corn residue.

Nitrogen loss is 13.6 pounds per ton, worth $9.85.

Phosphate loss of 3.6 pounds per ton, or $1.33 per ton.

Potash loss of 19.7 pounds per ton, worth $4.33 per ton.

Based on data from the 2013 Iowa State University custom rate survey, the costs for chopping, raking, baling and removing large bales from the field, and hauling bales 30 miles to an ethanol plant, would be $55.65 an acre.

This analysis shows an advantage of $76.09 per acre in favor of not selling residue. And it doesn’t include the other economic and environmental benefits you’ll lose by selling residue. Unfortunately, a few seed companies and university agronomists are advocating that partial stover removal is necessary to produce a high-yielding continuous corn crop.

Yet, numerous no-tillers, who are having success with continuous corn argue that excessive residue isn’t a concern. The folks advocating for removing a portion of the corn stover say it’s needed to meet the management challenges with continuous corn. But that’s no problem for no-tillers who have proven over the years to be top-notch crop managers and innovators.

Some recommendations being put out by university staffers are the exact opposite of what no-tillers have learned to do. An example is a suggestion that growers should turn off the chaff spreader when planning to remove residue. No-tillers know it’s critical to spread residue over the full width of the combine’s header.

Some agronomists argue the amount of corn stover left in highly productive, relatively flat, continuous-corn fields generally exceeds the minimum amount needed to maintain soil health and productivity, and could be turned into a cash crop for ethanol production. In addition, they’re promoting the idea that partial stover removal will lead to accelerated spring soil warming and drying, improved stand establishment, reduced nitrogen immobilization and less disease pressure.

Aren’t those the same arguments some agronomists have used for 4 decades to discourage the further adoption of no-till? Yet, for more than 40 years, innovative no-tillers have overcome these challenges.

Environmental Impact

Purdue University research indicates that removing crop residue for ethanol production from conventionally tilled, continuous-corn ground requires careful management to avoid soil erosion and reduce greenhouse gas emissions lost to the environment. However, the researchers reported that switching to no-till and/or adding cover crops can reduce the environmental impact of stover removal.

Ronald Esdaile, a long-time no-till educator in Moree, Australia, says you should think long and hard before deciding to remove residue for any reason from no-tilled fields. “Residue plays a vital role in soil erosion control, soil-temperature control, soil moisture control, weed suppression by toxins, shading and fertility control,” he says.

“Residue is probably the best weapon you have to control these factors.” So let’s make sure that we keep all of those highly valuable no-till crop residues at home.