Creating Sustainable Supply Chains for Cellulosic Biofuels

July 17, 2014 | Jim Lane

Growers reporting increased yields, revenues with stover harvest.

Natural Resources Conservation Service says “By making wise management decisions, removing residue can be done sustainably.”

What are the opportunities and the must-knows, for growers and project developers?

For those who were not able to register for our Digest webinar on “Creating Sustainable Supply Chains for Cellulosic Biofuels,” the recorded version of the 60-minute session is now available for playback here.

There are a number of surprising findings from the webinar, worth sharing.

1. Stover harvest increased corn yield in 93% of trials

2. 5.2 bu/acre corn yield advantage w/stover harvest.

3. Growers realized a $36 per acre increase in profit per acre, after fertilizer replacement, stover income and yield gain. Farmers with manure resources (e.g. from hog farming) can improve on these results further by reducing fertilizer replacement needs.

4. Partial Stover Harvest can Replace other Residue Management Practices. 40% of farmers in the DuPont stover program reduced tillage intensity in 2013 or reported they were planning to do so in 2014.

5. The specific rotation and tilling practice has a major impact on stover harvest. Corn-soy rotations deliver 1.2 less tons of stover per acre.

6. According to NCRS, “Removing residue can have a negative affect on soil health but by making wise management decisions it may be done sustainably.”

7. To increase an SCI (Soil Conservation Index) score, the NRCS suggests:

Raise crops that produce high amounts of residue; Utilize cover crops, seed early, to increase organic matter; Utilize manure or crop mulch to add organic matter; Limit the Number of tillage trips; Limit the amount of soil disturbance; Minimize the amount of wind and water erosion; Use production techniques that increase crop and crop residue.

8. Crop management has to evolve to make stover harvesting work. Sheet and rill erosion is not always visible; and generally controlled by reducing tillage and leaving residue on the soil surface during time of high rainfall “April, May, June”

In a note about the webinar for Farm Industry News, Lynn Grooms noted:

“John Maxwell grows corn south of Nevada, IA, and has been working with DuPont since 2012 to study the sustainable harvest of corn stover as a cellulosic ethanol feedstock. In a webinar on cellulosic ethanol supply chains hosted by Biofuels Digest this week, Maxwell cited several agronomic benefits of removing corn stover: reducing tillage (and associated labor and fuel costs), warming the soil for spring planting, reducing the number of overwintering insects and improving corn yield. Maxwell added that he applies hog manure on the corn to improve organic matter levels.

“Maxwell and other corn growers in north central Iowa will be supplying corn stover to the DuPont Industrial Bioscience biorefinery in Nevada, IA. John Pieper, corn stover feedstock workstream lead for DuPont, said that the facility (which will have a nameplate capacity of 30 million gallons per year when construction is completed) will annually collect 375,000 tons of corn stover from approximately 190,000 acres. This represents about 25 percent of the corn acres within a 30-mile radius of Nevada.”

Grooms’ complete summary of the webinar is here.