Oakes Irrigation Research Site

Carrington Research Extension Center * North Dakota State University

P.O. Box 531, Oakes, ND 58474-0531, Phone: (701) 742-2744, FAX: (701) 742-2700, E-mail:

Optimum Corn Stover Removal for Biofuels and the Environment

L. Besemann and H. Eslinger

The 2007 U.S. energy bill calls for 36 billion gallons of ethanol to be produced by 2020. In 2007 the U.S. produced 6.5 billion gallons of ethanol. If corn grain was able to supply 15 billion gallons of ethanol, 21 billion gallons of ethanol would have to come from cellulosic material (biomass) to meet the 2020 mandate. The production of 21 billion gallons of cellulosic ethanol will require 350 million tons of dry biomass. Presently, perennial grasses and corn stover are the most available. About 194 million tons of biomass is produced in U.S. production agriculture annually, with 75 million tons coming from corn stover. Therefore corn stover is being looked at to play a major role in cellulosic ethanol production.

Before we commit ourselves to using corn stover for fuel we need to study the environmental and economic consequences of this action. What effect will stover removal have on soil organic matter, soil erosion and ultimately sustainability of the land resource?

The objective of this study is to determine what rates of stover removal within different cropping systems are conducive to maintaining and possibly improving the productive capacity of the land while providing a renewable energy source.

MATERIALS AND METHODS

Rotations:

Block I: 2015 – field corn, 2014 - field corn, 2013 - field corn, 2012 - field corn, 2011 - field corn, 2010 - field corn, 2009 field corn, 2008 – field corn, 2007 - field corn.

Block II: 2015 – field corn, 2014 - soybean, 2013 - field corn, 2012 - soybean, 2011 - field corn, 2010 soybean, 2009 field corn, 2008 - soybean, 2007 - field corn.

Block III: 2015 – soybean, 2014 - field corn, 2013 - soybean, 2012 - field corn, 2011 - soybean, 2010 field corn, 2009 - soybean, 2008 - field corn, 2007 - onion.

Soil:

Embden sandy loam, Hecla sandy loam and Maddock sandy loam.

Block I: pH = 6.3; 2.4% organic matter; soil N 34 lbs/acre; soil P and soil K were very high; soil S was medium.

Block II: pH = 6.5; 2.3% organic matter; soil N 23 lbs/acre; soil P and soil K were very high; soil S was high.

Block III: pH = 6.5; 1.7% organic matter; soil N 28 lbs/acre; soil P was very high; soil K was high; soil S was low.

Seedbed preparation:

Strip-till April 24 with an Orthman strip-till machine.

Hybrid:

Corn: Wensman W90941STX RIB.

Variety:

Soybean: Dairyland DSR 0404 R2Y.

Planting:

Block I: Corn, May 1 in 30-inch rows @ 33,000 seeds/acre.

Block II: Corn, May 1 in 30-inch rows @ 33,000 seeds/acre.

Block III: Soybean, May 22 in 30-inch rows @ 174,200 seeds/acre.

Fertilizer:

Block I: Stream bar 12 lbs N/acre and 40 lbs P2O5/acre as 10 34-0 May 5, fifty lbs N/acre as 28-0-0 May 5, 13 lbs N/acre and 18 lbs S/acre as 15-0-0-20 May 7. Sidedress 145 lbs N/acre as 28 0 0 June 12.

Block II: Stream bar 12 lbs N/acre and 40 lbs P2O5/acre as 10 34-0 May 5, fifty lbs N/acre as 28-0-0 May 5, 13 lbs N/acre and 18 lbs S/acre as 15-0-0-20 May 7. Sidedress 145 lbs N/acre as 28-0-0 June 12.

Block III: Stream-bar 12 lbs N/acre and 40 lbs P2O5/acre as 10-34-0 May 5.

Irrigation:

Hand move sprinkler irrigation as needed.

Pest control:

Block I: Harness (2 pt/acre) May 8, Laudis (3 oz/acre) + AAtrex 9-O (0.5 lb ai/acre) + Destiny (0.05% v/v) + AMS (1½ lbs/acre) + Interlock (4 oz/acre) June 4.

Block II: Harness (2 pt/acre) May 8, Laudis (3 oz/acre) + AAtrex 9-O (0.5 lb ai/acre) + Destiny (0.05% v/v) + AMS (1 ½ lbs/acre) + Interlock (4 oz/acre) June 4.

Block III: Roundup (30 oz/acre) + AMS (1 lb/10 gal) June 4 and Roundup (30 oz/acre) + AMS (1 lb/10 gal) + MON 63410 (1.5 qt/acre) June 23.

Remote sensing:

Remote sensing was achieved with an Opti-Sciences CCM 200 Plus chlorophyll meter and a Holland Crop Circle ACS active canopy sensor (normalized difference red edge NDRE).

Harvest:

Block I: Hand harvested the entire length (27 feet) of rows 6 and 7 from each plot on October 12 and October 13.

Block II: Hand harvested the entire length (27 feet) of rows 6 and 7 from each plot on October 13.

Block III: Harvested with a JD 4400 combine (48 rows 108 feet long, recorded with a weigh wagon) on September 30.

RESULTS BLOCK I (Corn/Corn) - 2015

Corn stover was removed at the 33, 67 and 100 percent removal rates in block I (corn/corn rotation). Stover removal had no significant effect on grain yield, moisture and test weight at the 95 percent confidence level. Stover removal had no effect on chlorophyll readings (Opti-Science CCM 200), Normalized Difference Red Edge (NDRE) indice (Holland Crop Circle ACS 430) and stalk nitrate-N (Table 1) at the 95 per cent confidence level. Longer term data from 2009 to 2015 is presented in Table 2. The effect on revenue for the higher yield of the 100 percent removal rate compared to the 0 percent removal rate when the cost of N, P and K are accounted for is shown in Figure 1.

RESULTS BLOCK II (Corn/Soybean) - 2015

Stover removal rates of 33, 67, and 100 had no effect on grain yield, moisture or test weight (Table 3).

RESULTS BLOCK III (Soybean/Corn) - 2015

All soybean plots were combine harvested and bulked. The soybeans yielded 56.7 bu/acre @ 13 % (harvest moisture = 9.2%) and had a test weight of 57.2 lbs/bu.

Figure 1. The net return when the fertility cost leaving the field is subtracted from the yield

advantage in 100 percent removal plots compared to 0 percent removal plots for corn on corn

2008 to 2014 (Mean) at the Oakes Irrigation Research Site.

Table 1. The affect of corn stover removal from 0 to 100% on grain yield and other agronomic parameters for corn on corn plots 2015.

Grain

Stalk DM

Chlorophyll

Stover

Grain

Yield

Harvest

Test

Stalk DM

Removal

Meter

Stalk

Fall soil

Removal

Yield¹

2009-14

Moisture

Weight

Removal²

2008-14

Reading³

NDRE⁴

Population

Nitrate-N

bu/ac

lb/bu

------ ton/ac ------

4-Aug

5-Aug

plants/ac

ppm

lbs

195.1

213.1

15.2

54.8

0.0

57.2

0.3244

32670

1929

201.4

218.8

15.4

55.2

1.8

2.2

58.7

0.3278

32025

1737

202.6

220.3

15.3

54.1

2.1

3.3

62.6

0.3240

31864

1660

100

205.7

221.2

15.3

54.5

3.5

5.0

58.7

0.3179

32347

1549

Mean

201.2

15.3

54.6

1.8

59.3

0.3235

32226

1719

C.V. (%)

6.3

2.0

1.1

9.9

3.8

0.9

3.8

16.4

52.0

LSD 0.10

0.24

2.9

0.0039

LSD 0.05

0.29

3.6

0.0048

Table 1. The affect of corn stover removal from 0 to 100% on grain yield and other agronomic parameters for corn on corn plots 2015 (continued).

Stover

Seed

Emerge

Silk

Nutrients in stover²

Nutrient Value

Removal

Oil

Protein

Starch

Date

20152

2008-2015

--------------%----------------

------ lb/acre ------

------ $/ac ------

2.2

9.2

73.5

22-May

22-Jul

0.0

2.2

8.9

73.7

20-May

20-Jul

1.3

2.2

9.0

73.7

20-May

20-Jul

2.1

100

2.2

8.8

73.9

20-May

20-Jul

2.8

Mean

2.2

8.9

73.7

21-May

20-Jul

1.5

C.V. (%)

13.2

2.7

0.6

27.3

45.9

44.4

30.8

LSD 0.10

0.8

1.3

9.6

0.9

7.5

LSD 0.05

0.9

1.7

1.1

9.3

Planting Date = May 1; Harvest Date = October 13 ; Previous Crop = Corn.

Fertilizer Rate lbs/acre = 220 N, 40 P₂O₅, 18 S; Irrigation = 12.0 inches.

¹Yield adjusted to 15.5% moisture.

² Corn stover removed spring of 2015 from 2014 corn crop.

³Opti-Science CCM 200.

⁴Holland Crop Circle ACS active canopy sensor (normalized difference red edge) - NDRE.

Table 2. Corn on Corn Stover Removal - NDSU Oakes Irrigation Research Site 2009-2015.

Stover

Grain

Harvest

Test

Chlorophyll

Reading

Stalk

Grain

Silk

Mature

Removal

Yield

Moisture

Weight

Reading

NDRE

Nitrate-N

Protein

Date

bu/ac

lb/bu

ppm

213.1

20.8

54.1

54.4

0.3545

2362

8.6

24-Jul

29-Sep

218.8

20.1

54.7

55.6

0.3566

2760

8.6

22-Jul

28-Sep

220.3

20.1

54.6

57.1

0.3570

2740

8.6

22-Jul

27-Sep

100

221.2

19.6

54.8

56.5

0.3525

2915

8.7

21-Jul

27-Sep

Mean

218.4

20.2

54.5

55.9

0.3551

2694

8.6

22-Jul

28-Sep

Table 3. The affect of corn stover removal from 0 to 100% on grain yield and other agronomic parameters for corn on soybean plots 2015.

Previous Year

Grain

Stover

Grain

Yield

Harvest

Test

Fall Soil

Seed

Emerge

Silk

Removal

Yield¹

2009-15

Moisture

Weight

Chlorophyll²

NDRE³

Nitrate-N

Population

Oil

Protein

Starch

Date

bu/ac

lb/bu

4-Aug

5-Aug

lbs

plants/ac

------------%-------------

217.9

225.8

14.9

55.3

61.7

0.3272

114

33074

2.4

9.1

73.3

20-May

19-Jul

211.5

220.8

14.3

55.4

61.4

0.3268

124

33396

2.4

8.9

73.4

20-May

20-Jul

219.4

221.8

14.3

55.6

61.0

0.3371

151

33396

2.4

8.9

73.6

20-May

19-Jul

100

216.2

224.3

14.6

55.6

62.1

0.3286

120

33235

2.5

9.0

73.4

20-May

19-Jul

Mean

216.3

14.5

55.5

61.5

0.3299

127

33275

2.4

9.0

73.4

20-May

19-Jul

C.V. (%)

4.1

2.4

0.9

6.8

2.2

36.0

3.2

10.7

2.2

0.6

LSD 0.10

LSD 0.05

Planting Date = May 10; Harvest Date = October 17 ; Previous Crop = Corn.

Fertilizer Rate lbs/acre = 220 N, 40 P₂O₅, 18 S; Irrigation = 12.0 inches.

¹Yield adjusted to 15.5% moisture.

²Opti-Science CCM 200.

³Holland Crop Circle ACS active canopy sensor (normalized difference red edge) - NDRE.

Oakes Irrigation Research Site

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