AMES, Iowa — In the cornfields of central Iowa, employees of newly created, small, local businesses are preparing and collecting corn stover — the stalks, leaves and cobs left after grain harvest — as feedstock for the DuPont Biofuels Solutions cellulosic ethanol facility in Nevada, Iowa, which is expected to launch production this fall. The corn stover harvesters were trained by and have access to support from Iowa State University researchers, who continue to work to improve efficiency and reduce costs.
“What we are trying to do is put a supply chain in place as was done for corn, beginning in the 1800s and evolving into what we have today. But stover bales are a bulkier product and we need that supply chain to fully evolve over just a few years,” said Matthew Darr, associate professor of agricultural and biosystems engineering.
Farmers with animals have harvested corn stover for bedding and silage for decades. But collecting stover as biofuel feedstock and creating and managing a corn stover supply chain on an industrial scale is new to Iowa corn producers and biorefinery operators. In 2009, the Iowa State corn stover supply chain research team led by Darr, began working with DuPont at the BioCentury Research Farm researching ways to grow and develop an industrial feedstock supply chain and achieve a quality and economically viable product for biorefineries, while maintaining soil health and quality.
Researchers and farmers know that leaving some corn stover in place after harvest is important for erosion control, replenishing soil organic matter and returning crop nutrients to the soil. But as corn yields per acre have risen over time, seeds are planted more densely and corn stover left after grain harvest has increased. With yields reaching 180 bushels/acre, an increasing percentage of stover on Iowa fields can be harvested, providing crop production benefits to farmers and an economical feedstock for biorefineries.
In 2013, with funding from the Leading the Bioeconomy Initiative funded by the Iowa Legislature, project researchers developed supply chain training sessions and educated over 70 supply chain employees. Training sessions focused on five distinct areas of the biomass supply chain: windrowing equipment, baling equipment, managing biomass moisture, maximizing biomass quality and maximizing productivity logistics.
Trainee knowledge grew in all areas, with growth in windrowing and biomass quality. The economic value of the training was calculated by measuring the direct net value of improved biomass quality and supply chain logistics. For the 2013 corn stover harvest season this value had a direct impact of more than $225,000 to local new businesses that were engaged in feedstock collection.
“Our process improvement training also led to a 4.5 percent increase in corn stover product density, which reduces the number of semi-trucks on Iowa roads by more than 1,200 per year,” said Darr.
The team also developed software and data analytics tools focused on providing real-time information to the 15-20 small businesses that are supporting the biomass supply chain in central Iowa. This information is located on an online web portal and provides instant access for each business to monitor machinery performance throughout the harvest season. It also focuses on providing key information to support decisions that each business will make throughout the harvest season to ensure they maintain profitability and continue to grow the biomass supply chain industry.
“The real-time information systems facilitate just-in-time logistics for machinery support and up-keep for each small business,” said Darr. “This will help them manage parts and fuel inventory, and maximize uptime of the machines.”
Andy Moser, a corn farmer in Nevada, Iowa, took the training to start up his new corn stover harvesting business and uses the online web portal. He had done stover harvest before for cattle feed, but needed the training to be able to harvest stover for DuPont. This fall Moser Harvesting, LLC will collect stover on 15,000 corn acres.
“Matt and his team have a lot of time invested in researching this, so I trust what they have to say about it,” Moser said. “And the data collection on the ash and the bale density that the team continues to do really helps us through the year to adjust our machines for maximum efficiency.”