Stover Update

DuPont Cellulosic Ethanol

Delivering an Advantaged Biomass Fuel

Stover Harvest Season

Harvest started September 26th and ended December 7th 72 day harvest season Extended season due to late corn

planting in Iowa Rain, drizzle and snow Experienced normal and extreme baling

conditions

2014 Stover Harvest - - - 60,000 acres

Corn Stover: Benefits and Limitations

Conservation Benefits: Protect soil from erosion Maintain soil organic matter Cycle crop nutrients

Agronomic Limitations: Interfere with crop establishment and

early growth Immobilize nitrogen & harbor crop

pathogens Necessitate tillage

Improved Field Condition at Planting

Spring Residue following Soybean

Faster Stand Establishment

2012 2013

-10

-5

0

5

10

15 St

over

Har

vest

Yie

ld A

dvan

tage

(b

u/ac

re)

Corn Yield Advantage with Stover Harvest

Win rate: Stover harvest increased corn yield in 93% of trials

On Average: 5.2 bu/acre corn yield advantage w/stover harvest

2012 2013

-$15 $24

$22 $32

-$30

-$15

$0

$15

$30

$45 $/

Acre

Fertilizer Replacement

Stover Income

Yield Gain

Net Profit

DuPont Stover Harvest: Grower Value

Results for 14 on-farm research trials in Central Iowa in 2012 and 2013

Analysis based on $4.30 corn; $15/ton stover; $0.51 P2O5; and $0.38 K2O

Convenience Factors

Eliminate stalk chopping Remove fall tillage pass Less aggressive tillage No need for fall AMS Enter field earlier in spring 40% of farmers in the DuPont

stover program reduced tillage intensity in 2013 or reported they

were planning to do so in 2014

2.2

0.4

4.8

0.5

3.4

2.3

5.6

3.5

0

1

2

3

4

5

6

Moldboard Plow

Conserv. / No-Till

Moldboard Plow

Conserv. / No-Till

Stov

er to

Ret

ain

(tons

/acr

e)

Prevent Soil Erosion Maintain Soil Carbon

Source: Wilhelm et al. 2007. Corn Stover to Sustain Soil Organic Carbon Constrains Biomass Supply. Agronomy Journal. 99:1665-1667.

2.0 tons/acre 0.8 tons/acre

Stover @ 180 bu/acre grain

How Much Stover can be Harvested Sustainability?

Field-Specific Soil Health Assessment

Soil Types

Soil Organic Matter + -

Weather Management

Productivity

Field Location

Copyright © 2012 DuPont. All rights reserved.

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