Vilsack champions cover crop biomass, NRDC report lays out path to doing it right

The world is currently experiencing the second surge in global food prices in three years, leading to food shortages and political unrest in many regions. With media and governments increasingly scrutinizing the causes of volatility in world food markets, it’s not surprising that Congress asked Secretary of Agriculture Tom Vilsack to testify last week on U.S. biofuels mandates and their effects on food prices. Vilsack’s comments seemed, unfortunately, to come straight from the corn ethanol industry’s talking points, but he did use the opportunity to raise awareness about the ways in which we can produce more biomass for things like biofuels without competing with our food supply.

Calling for more conversations about a “redesign of the agricultural production systems in this country”, Vilsack  cited double, or cover, cropping— the practice of planting a second crop in coordination with a main crop—as one practice America’s farmers can employ to produce biomass for bioenergy without diverting crops from food and feed markets. [Vilsack’s statements got some positive coverage in corners such as The Progressive Farmer’s ag policy blog].

NRDC released a report last month called Second Harvest: Bioenergy from Cover Crop Biomass, which argues that if done carefully, cover crops harvested for bioenergy production could provide extra income to farmers without significantly impacting the amount of land available to grow food crops.  Cover crops, the report concludes, could also deliver many environmental benefits, including improved water infiltration in soils; reduced erosion, runoff, and sedimentation; reduced nitrogen leaching; gains in soil organic matter; and enhanced carbon sequestration. These benefits make cover crop biomass an attractive next-generation biomass feedstock. 

By contrast, the U.S. corn ethanol industry today uses approximately 40% of our annual corn crop. Vilsack, when pressed on ethanol production’s corn consumption and its impact on food prices, pointed to a myriad of drivers of increased food prices but exempted the corn ethanol industry because of its rising productivity:

“I would say that there are many reasons why there are food shortages globally, but none of them have to do with American farmers and ranchers in a sense that we continue to be extraordinarily productive. Storms, droughts, floods in other parts of the world, export controls that were imposed by other countries, the currency issues, there are a multitude of reasons why we have some of the shortages that we see today in other parts of the globe.”

The Renewable Fuels Association (RFA), a leading corn ethanol industry lobby group, uses the same argument on their blog. U.S. corn ethanol producers, they admit, are using an increasing percentage of the global grain supply. But that supply keeps growing, so, in their view, the fact that the industry now uses 3% of the world’s grains is not significant enough to impact world food prices. The RFA, like the Secretary, point instead to extreme weather events and the impacts of export policies, market speculation, and oil prices, as the real culprits behind soaring food prices.

RFA and Vilsack are indeed correct that a myriad of complex factors all play a role in increasing the tightness of global grain markets. But both fail to acknowledge that it is impossible to segregate the impact of biofuels mandates on food prices from other factors like oil prices or weather because these factors multiply each other—a critical point that biofuels expert Tim Searchinger made in his Washington Post editorial earlier this year, which we discussed here.

The reality is that U.S. biofuels mandates, along with similar mandates in other industrialized countries, population growth, increasing meat consumption, weather shocks, market speculators bidding up the prices of grain futures, and a host of other variables, all affect complex agricultural commodity markets. And perhaps the world’s farmers could keep up if U.S. biofuels mandates were the only factor putting pressure on the supply of food and cropland in today’s grain markets. But taken together, these factors add up to a very tight market where any single shock causes fear, government hoarding, and hunger.

NRDC’s report on cover cropping makes clear that we have the technologies to avoid pitting the need to drive our cars against the need to feed the world's hungry—and that smart bioenergy policies should support those technologies. The report promotes the practice of traditional cover cropping and its environmental benefits, while documenting the benefits and challenges of harvesting cover crops as a source of biomass. It also assesses the various policy incentives that could help scale up the use of cover crops, and recommends research that would help illuminate which planting and harvesting practices could maximize environmental benefits in different cropping systems. The report additionally proposes vehicles for public investment to support the research, development, and demonstration projects that will help identify best practices.

The report clarifies that the cover crop, or mix of crops, that yields the greatest amount of aboveground biomass may not maximize environmental benefits to the water or soil—and there are a host of other trade-offs that must be evaluated when assessing the environmental performance of cover cropping systems. The study concludes that cover cropping for biomass production requires careful evaluation of crop pairings, site-specific soil and climate conditions, and management practices in order to be successful, and that trade-offs are inevitable. Indeed, a key finding states that a holistic approach that considers the way residues of both the main and cover crop are managed is critical to any evaluation of the environmental performance of the overall cropping system. The report concludes that researchers will have to answer these critical questions, evaluating how to simultaneously optimize three factors: yield from the cover crop, yield from the main crop, and environmental benefits. Additional research will need to identify the best crop mixes and to develop best management practices based on location, soil type, climate, and other factors.

Our next step here at NRDC is to profile some farmers employing cover cropping for the purpose of biomass production. Stay tuned!