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

K. Cooper, 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: 2016- field corn, 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: 2016 - soybean, 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: 2016- field corn, 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 = 6.2; 2.7% organic matter; soil N 79 lbs/acre; soil P was very high; soil K was very low; soil S was medium.

Block II: pH = 6.0; 2.4% organic matter; soil N 127 lbs/acre; soil P was very high: soil K was high; soil S was medium.

Block III: pH = 7.1; 1.5% organic matter; soil N 23 lbs/acre; soil P and soil K was very high; soil S was low.

Seedbed preparation:

Strip-till May 6 with an Orthman strip-till machine.

Hybrid:

Corn: Wensman W8184VT2RIB.

Variety:

Soybean: Northrup King S10P9.

Planting:

Block I: Corn, May 6 in 30-inch rows @ 33,000 seeds/acre.

Block II: Soybean, May 9 in 30-inch rows @ 174,200 seeds/acre.

Block III: Corn, May 6 in 30-inch rows @ 33,000 seeds/acre.

Fertilizer:

Block I: Stream-bar 12 lbs N/acre and 40 lbs P₂O₅/acre as 10-34-0; 13 lbs N/acre and 18 lbs S/acre as 15-0-0-20 May 9. Stream-bar 50 lbs N/acre as 28-0-0 May 10. Sidedress 145 lbs N/acre as 28‑0‑0 June 17.

Block II: Stream-bar 12 lbs N/acre and 40 lbs P₂O₅/acre as 10-34-0 May 9.

Block III: Stream-bar 12 lbs N/acre and 40 lbs P₂O₅/acre as 10-34-0; 13 lbs N/acre and 18 lbs S/acre as 15-0-0-20 May 9. Stream-bar 50 lbs N/acre as 28-0-0 May 10. Sidedress 145 lbs N/acre as 28‑0‑0 June 17.

Irrigation:

Overhead sprinkler irrigation as needed.

Pest control:

Block I: Roundup (40 oz/acre) + Harness (2 pt/acre) + AMS (1 lb/10 gal) + Preference (1.6 oz/10 gal) May 10, Laudis (3 oz/acre) + Roundup (32 oz/acre) +NIS (1 pt/100 gal) + AMS (1 lb/10 gal) + Interlock (4 oz/acre) June 20.

Block II: Roundup (40 oz/acre) + Authority Elite (25 oz/acre) + AMS (1 lb/10 gal) + Preference (1.6 oz/10 gal) May 10. Endura (5.5 oz/acre) July 15

Block III: Roundup (40 oz/acre) + Harness (2 pt/acre) + AMS (1 lb/10 gal) + Preference (1.6 oz/10 gal) May 10 and Laudis (3 oz/acre) + Roundup (32 oz/acre) + NIS (1 pt/100 gal) + AMS (1 lb/10 gal) + Interlock (4 oz/acre) June 20.

Remote sensing:

Remote sensing was achieved with an Opti-Sciences CCM 200 Plus chlorophyll meter

Harvest:

Block I: Hand harvested 27 feet from rows 6 and 7 from each plot on October 19 and October 20.

Block II: Harvest September 29 with an Almaco plot combine.

Block III: Hand harvested 27 feet from rows 6 and 7 from each plot on October 20.

RESULTS BLOCK I (Corn/Corn) - 2016

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 percent confidence level. Longer term data from 2009 to 2016 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 (Soybean/ Corn) - 2016

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.

RESULTS BLOCK III (Corn/ Soybean) - 2016

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

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 2015 (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 in 2016.

Grain

Stalk DM

Chlorophyll

Stover

Grain

Yield

Harvest

Test

Stalk DM

Removal

Meter

Stalk

Fall soil

Removal

Yield¹

2009-16

Moisture

Weight

Removal²

2008-15

Reading³

Population

Nitrate-N

bu/ac

lb/bu

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

3-Aug

plants/ac

ppm

lbs

233.3

215.6

18.2

57.5

0.0

47.3

34770

1816

236.4

221.0

18.6

57.4

0.8

2.1

49.0

34346

1192

243.0

223.2

18.4

57.4

0.8

3.0

49.9

33838

1058

100

251.1

224.9

18.5

57.2

1.7

4.6

51.7

35173

1061

Mean

240.9

18.4

57.4

0.8

49.5

34531

1282

C.V. (%)

3.8

2.0

0.6

16.3

3.6

2.2

64.4

26.0

LSD 0.10

11.8

0.48

0.2

2.3

975

LSD 0.05

14.6

0.2

2.8

1203

Table 1. The affect of corn stover removal from 0 to 100% on grain yield and other agronomic parameters for corn on corn plots in 2016 (continued).

Stover

Seed

Emerge

Silk

Nutrients in stover²

Nutrient Value

Removal

Oil

Protein

Starch

Date

2016

2008-2015

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

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

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

3.00

8.6

73.48

21-May

20-Jul

0.0

2.98

8.5

73.55

20-May

20-Jul

0.5

2.95

8.6

73.63

20-May

19-Jul

0.5

100

3.00

8.5

73.63

20-May

19-Jul

0.9

Mean

3.0

8.6

73.6

20-May

19-Jul

0.5

C.V. (%)

6.9

1.6

0.6

22.3

50.5

24.0

16.8

LSD 0.10

0.5

0.6

2.2

0.3

1.7

1.0

LSD 0.05

0.6

0.8

2.7

0.4

2.1

1.2

Planting Date = May 6; Harvest Date = October 20 ; 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 2016 from 2015 corn crop.

³Opti-Science CCM 200.

Table 2. Corn on Corn Stover Removal - NDSU Oakes Irrigation Research Site 2009-2016.

Stover

Grain

Harvest

Test

Chlorophyll

Reading

Stalk

Grain

Silk

Mature

Removal

Yield

Moisture

Weight

Reading

NDRE¹

Nitrate-N

Protein

Date

Date²

bu/ac

lb/bu

ppm

215.6

20.5

54.6

53.9

0.3545

2294

8.7

23-Jul

29-Sep

221.0

19.9

55.0

55.2

0.3566

2564

8.6

22-Jul

28-Sep

223.2

19.9

54.8

56.9

0.3570

2530

8.6

21-Jul

27-Sep

100

224.9

19.5

55.0

56.2

0.3525

2683

8.7

20-Jul

27-Sep

Mean

221.2

19.9

54.9

55.6

0.3551

2518

8.6

22-Jul

28-Sep

¹Data only available from 2010-2015.

²Maturity dates from 2009-2014

Table 3. The affect of corn stover removal from 0 to 100% on grain yield and other agronomic parameters for corn on soybean plots 2016.

Grain

Chlorophyll

Stover

Grain

Yield

Harvest

Test

Meter

Stalk

Fall soil

Seed

Emerge

Silk

Removal

Yield¹

2009-16

Moisture

Weight

Reading2

Nitrate-N

Population

Oil

Protein

Starch

Date

bu/ac

lb/bu

3-Aug

ppm

lbs

plants/ac

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

267.4

231.0

18.8

57.7

49.4

934

36418

2.6

8.6

74.3

20-May

19-Jul

253.6

224.9

18.7

57.7

49.5

688

35135

2.9

8.4

73.9

20-May

19-Jul

250.7

225.4

18.3

57.8

47.1

595

35237

2.7

8.2

74.3

20-May

18-Jul

100

258.1

228.5

18.7

57.4

49.1

869

35126

3.0

8.4

73.8

20-May

18-Jul

Mean

257.5

18.6

57.6

48.8

771

20.8

35479

2.8

20-May

18-Jul

C.V. (%)

5.3

2.2

0.7

5.4

52.3

56.4

1.4

10.2

3.4

0.9

0.0

LSD 0.10

656

0.37

0.5

LSD 0.05

810

0.7

Planting Date = May 6; Harvest Date = October 20 ; 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.

Oakes Irrigation Research Site

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Strip-tilled corn N rate; corn corn rotation

Strip-tilled corn N rate; corn soybean rotation