This document summarizes DuPont's 2014 corn stover harvest from 60,000 acres in central Iowa. The harvest occurred from September 26th to December 7th, spanning 72 days, due to a late corn planting season with rain, drizzle and snow. Corn stover provides both conservation benefits like reducing soil erosion and maintaining soil organic matter, but also has agronomic limitations like interfering with early crop growth. Field trials showed improved soil conditions at planting and faster stand establishment with stover harvest. On average, stover harvest increased corn yields by 5.2 bushels per acre. A financial analysis estimated farmers could gain $32 per acre in net profit from stover income, fertilizer replacement value, and yield increases.

2. DuPont Cellulosic Ethanol
Delivering an Advantaged Biomass Fuel

3. 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

4. 2014 Stover Harvest - - - 60,000 acres

5. Corn Stover: Benefits and Limitations
Conservation Benefits:
Agronomic Limitations:
 Protect soil from erosion
 Maintain soil organic matter
 Cycle crop nutrients
 Interfere with crop establishment and
early growth
 Immobilize nitrogen & harbor crop
pathogens
 Necessitate tillage

6. Improved Field Condition at Planting
Spring Residue following Soybean

7. Faster Stand Establishment
2012
2013

8. Corn Yield Advantage with Stover Harvest
Stover Harvest Yield Advantage
(bu/acre)
15
On Average: 5.2 bu/acre corn yield advantage w/stover harvest
Win rate: Stover harvest increased corn yield in 93% of trials
10
5
0
-5
-10
2012
2013

9. DuPont Stover Harvest: Grower Value
$45
Results for 14 on-farm research trials
in Central Iowa in 2012 and 2013
$30
Analysis based on $4.30 corn; $15/ton
stover; $0.51 P2O5; and $0.38 K2O
$22
$32
$/Acre
$15
$0
$24
-$15
-$15
-$30
Fertilizer
Replacement
Stover
Income
Yield
Gain
Net
Profit

10. 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

11. How Much Stover can be Harvested Sustainability?
Stover to Retain (tons/acre)
6
5
Prevent Soil Erosion
Maintain Soil Carbon
5.6
Stover @ 180 bu/acre grain
4.8
4
0.8 tons/acre
3.4
3
2
2.0 tons/acre
3.5
2.3
2.2
1
0.5
0.4
0
Moldboard
Plow
Conserv. /
No-Till
Moldboard
Plow
Conserv. /
No-Till
Source: Wilhelm et al. 2007. Corn Stover to Sustain Soil Organic Carbon Constrains Biomass Supply.
Agronomy Journal. 99:1665-1667.

12. Field-Specific Soil Health Assessment
Field Location
Soil Types
Soil Organic Matter
-
Weather
Management
Productivity
+

13. Copyright © 2012 DuPont. All rights reserved.
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