Corn stover as a new industry
Considerable research is underway to turn corn stover from a byproduct to a co-product and earn additional value for corn growers beyond the sale of grain.
Two major in-field research projects connected with DuPont and Monsanto have very similar aspects. Questions being investigated include how much stover can be substantially removed each year, how can stover be appropriately gathered including the best equipment, what is the necessary way to store stover, are there agronomic advantages to removal of some stover and what is the value of the stover in terms of its nitrogen, phosphorus and potassium cost of replacement.
“Sustainable removal rates are going to be key, and that is a lot of what our project has revolved around. How do we harvest the stover without taking too much and then how do we use it?” said Steve Petersen, end-use market manager for Monsanto.
Monsanto is farther ahead in its research project with three years of data and working with companies, including ADM, that are interested in stover use as a feed ingredient, industrial uses (anhydrous ammonia feedstock, boiler energy feedstock, chemical ingredients, etc.) and cellulosic ethanol.
DuPont has connection to stover research through its joint venture with Danisco, a major provider of enzymes to the current corn ethanol industry. DuPont Danisco Cellulosic Ethanol (DDCE) has a cellulosic ethanol demonstration facility in Vonore, Tenn., and the stover research ties into providing feedstock for this plant and an eventual commercial cellulosic ethanol facility to be built, possibly in Iowa.
The Monsanto stover project has been focused primarily in Iowa during the past three years while DDCE’s effort was in Nebraska and Iowa for
The tremendous corn yields that are projected for coming years indicates that too much stover will be on the surface of fields, and in some cases, it already has negative consequences for farmers, especially those using no-till and minimum-till.
“The agronomic impacts are going to be key to the long-term sustainability for a biorefinery and the farmers,” said Kyle Althoff, director of feedstock development for DDCE. “Farmers are definitely interested in the impact on nutrients and soil organic matter of harvesting stover. And often we see a slight bump in yield when some stover is taken off because the soil can warm up faster in the spring, and it reduces the challenges of getting seed planted in the bed at the right depth. There are definitely potential advantages for many growers, but it has to be managed in a very sustainable way, not taking away too much organic material.”