Consider the Cob

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It’s not often we hear people standing up for stover—the stalks, shucks, etc., left in the field after corn is harvested. After all, it’s unapologetically called “trash” by  farm tillage experts and is considered a nuisance when putting in the following year’s crop. But on a western Minnesota farm last week it became clear these lowly field dregs need advocates more than ever. That’s because a new biomass initiative in the most recent Farm Bill could pose a real threat to these soil-friendly leftovers.

That threat is in the guise of the Biomass Crop Assistance Program (BCAP). Created by the 2008 Farm Bill and run by the Farm Service Agency, BCAP is set up to provide financial assistance to producers who deliver biomass material to  facilities for use as heat, power, biobased products or fuel. The program provides three types of payments to producers: direct, annual and cost-share. Both agricultural and forestry products are eligible.

BCAP, which could be fully implemented as early as this fall, may go a long ways toward assuring a steady supply of raw materials for budding biomass processing facilities. Among other things, the USDA will provide annual payments to help compensate for “lost opportunity costs” until the crops are established, and will provide money for the collection, harvest, storage and transportation of biomass crops.

This could be a modest, but important, strategy for removing some of the risk—for farmers and processors— involved in a thoroughly untested part of the energy sector.

BCAP could also help diversify our rural landscape and improve the environment. For example, one element of BCAP would cover 75 percent of the costs of establishing a perennial biofuels crop like native prairie.

But here’s the catch: a glance at the list of materials eligible for compensation under BCAP shows that even though commodity crops like corn cannot be part of the program, “crop residues” are. Namely, corn stover, corn cobs, rice hulls, wheat straw and “bagasse” (new word of the day, at least for me: bagasse is the residue left over after sugarcane or sorghum stalks are crushed).

Including crop residues on the BCAP eligibility list could lead to significantly less corn stover on Midwestern crop fields after harvest. That means less organic matter in the soil and soils that will be extremely vulnerable to water and wind erosion. As we’ve written in this blog before, this crop “trash” actually serves a very important purpose environmentally and agronomically.

Sure, farmers participating in BCAP have the choice of enrolling perennial crops in the program and not just sweeping their fields into black desert oblivion. But the reality is that farmers can only sign five-year contracts under BCAP. That provides little time to get a long-term perennial system like prairie up and running on a farm. That’s asking farmers to take on a significant risk at a time when profit margins are already thin or nonexistent.

There’s a very good chance that many corn farmers, feeling pressed by time and economics, will simply use BCAP as a way to get rid of residue, rather than as a launching pad for a biofuels production system based on diverse plant systems.

USDA soil scientist Sharon Lachnicht Weyers expressed such concerns at a field day last week in western Minnesota’s Pope County. The field day was organized to showcase farms participating in the Pope County Working Lands Initiative. This initiative is a partnership of farmers, natural resource agencies and educational institutions working to show environmental protection and productive agriculture can work on the same landscape. One of the “working lands” enterprises being researched on participating farms is the production of diverse prairie grasses for biofuels.

Indeed, participants in the field day took a tour of a 30-acre native prairie planted last year on the Mary Jo and Luverne Forbord farm near Starbuck. The Forbords are working with researchers to determine if this 16-species prairie can be harvested for biofuels, maybe even grazed, and still provide valuable ecosystem services.

Standing in the middle of this new planting, it was clear that a program like BCAP could give an enterprise like this a significant boost by removing some of the risk involved in establishing perennials, let alone utilizing them for the biofuels market.

But Weyers, who is a researcher at the USDA’s North Central Soil Conservation Research Laboratory,  isn’t sure that’s the way it will work out.

“There is a concern BCAP will just be used by conventional farmers who will go into a corn field and remove all the stover and cobs,” she said during the field day. “Pray for just the cob.”

If this scenario does come to dominate, it will make the planting of cover crops such as rye more important than ever. Such plantings can build the soil, disrupt weed cycles and keep more sediment out of our streams.

Right here in Minnesota, we’ve recently seen some exciting advancments in cover crop establishment and management. But the fact remains that the vast majority of crop farmers don’t utilize this soil-friendly tool. And recent cuts in state sustainable agriculture initiatives aren’t helping.

We need more resources directed not only at studying and promoting cover crops, but at figuring out exactly just how much crop residue we can remove before it starts having unsustainable consequences. Soil scientists say we don’t have as good a good handle on that as we should. Perhaps that’s something we should have figured out before including crop residue on the BCAP eligible materials list?

Weyers reminded me of how many crop residue unknowns there are when, during the Pope County field day, she expressed this ominous thought out loud: “Let’s just hope you don’t need the cobs to hold that stover down.”

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