Nitrogen Fertilization Nitrogen Fertilization for Ethanol Production for Ethanol Production with Sweet Sorghum with Sweet Sorghum and Cornand Corn
G. Stevens, R. Holou, M. Rhine and D. G. Stevens, R. Holou, M. Rhine and D. DunnDunn
University of Missouri-Delta CenterUniversity of Missouri-Delta Center
Portageville, MissouriPortageville, Missouri
60% of U.S. fuel from 60% of U.S. fuel from foreign countriesforeign countries
Fuel versus feed Fuel versus feed debatedebate
SwitchgrassSwitchgrass
>10 year old stands Missouri Bootheel
Nutrient PartitioningNutrient Partitioning
Roland Holou, PhD student
November 2007
Fresh wt 4.8 tons/acre
Dry wt 3.4 tons/acre
Sweet SorghumSweet Sorghum
University of Missouri-Delta Center 2007
Subfamily PanicoideaeSubfamily Panicoideae
C4 photosynthesisC4 photosynthesis Sugar cane (Sugar cane (SaccharineSaccharine hybrids) hybrids) Sweet sorghum (Sweet sorghum (Sorghum bicolorSorghum bicolor)) Maize (Maize (Zea maysZea mays))
WWII WWII Sugar Sugar RationinRationingg
First & Last
1942- 1947, two years after war ended
Moonshine- sugar from Moonshine- sugar from sweet sorghumsweet sorghum
Cheaper sugar for making ethanol.
Sweet sorghumSweet sorghum
PositivePositive Reports that it Reports that it
requires less requires less water and water and nitrogen than nitrogen than corn.corn.
NegativeNegative Infrastructure not Infrastructure not
developed to developed to handle large handle large quantities of quantities of juice.juice.
ObjectiveObjective
Sweet sorghum- Determine optimum Sweet sorghum- Determine optimum N rates for producing ethanolN rates for producing ethanol
Irrigated Tiptonville silt loam soil
Sweet sorghum– 0, 20, 40, 60, 80, 100, 120 lb N/acre
Corn- 0, 40, 80, 120, 160, 200, 240 lb N/acre
Sorghum variety: M81E, 4 replications
0
50
100
150
200
250
0 40 80 120 160 200 240
Corn
, bu
shels
per
acr
e
S S
org
hu
m,
ton
s p
er
acr
e
25
20
15
10
5
0
S Sorghum, fresh wt
dry wt
Corn and Sweet Corn and Sweet Sorghum Yields in Sorghum Yields in 20072007
Pounds N per acre
Corn
Sweet sorghum stalks, Sweet sorghum stalks, 20082008
0
10
20
30
40
50
0 40 80 120 160
Fertilizer Nitrogen, lb N/ acre
Sta
lk y
ield
, to
ns/
acr
e
Fresh weight
0
50
100
150
200
0 40 80 120 160 200 240 280
Fertilizer nitrogen, lb N/ acre
Corn
yie
ld, bush
els
/acr
eCorn yields, 2008Corn yields, 2008
Formerly Eastman Kodak Chemical Co. Batesville, Arkansas
Sorghum Stalks, 2007Sorghum Stalks, 2007
Component LbNet Wt.
%
Water 26,030 64
Sucrose 6,454 16
Glucose 414 1
Fructose 354 1
Unknown Water Extractables
2,348 6
Bagasse 5,199 13
Yeast conversionYeast conversion
Sucrose + H2O ------Sucrose + H2O ------ 2 Glucose 2 Glucose
342 18 180342 18 180
6,454 lb sucrose6,454 lb sucrose 6,794 lb 6,794 lb glucoseglucose
2*180= 360
Yeast conversionYeast conversion
Fructose + ½ O2 ------Fructose + ½ O2 ------ Glucose Glucose
164 16 180164 16 180
354 lb sucrose354 lb sucrose 389 lb glucose 389 lb glucose
Ethanol for sugarsEthanol for sugars
As lb GlucoseAs lb Glucose Sucrose 6,794Sucrose 6,794 Glucose 414Glucose 414 Fructose Fructose 389389
TotalTotal 7,586 7,586
Glucose Glucose 2 Ethanol + 2 2 Ethanol + 2 CO2CO2
180 46 44180 46 44
GlucoseGlucose EthanolEthanol
7,586 lb x 7,586 lb x 2(46)2(46) = 3,877 lb = 3,877 lb
180180
587 gal Eth/acre 587 gal Eth/acre (theoretical)(theoretical)
Based on 6.6 lb per gallonBased on 6.6 lb per gallon0.511/6.6 = 0.0774 gal Et/lb glucose
Sweet Sorghum Sweet Sorghum BagasseBagasseCompositionComposition Wt. %Wt. % LbsLbs
Acid Sol LigninAcid Sol Lignin 99 489489
Acid Insol LigninAcid Insol Lignin 2121 1,0921,092
ArabinanArabinan 44 187187
XylanXylan 1616 811811
MannanMannan >1>1 1010
GalactanGalactan >1>1 4242
GlucanGlucan 4444 2,2932,293
UnknownsUnknowns 55 276276
“chem correct term for cellulose”
Ethanol from celluloseEthanol from cellulose
Glucan + H2O Glucan + H2O Glucose Glucose
180/(180-18) = 1.1 lb glucose/lb 180/(180-18) = 1.1 lb glucose/lb glucanglucan
2,293 lb x 1.1 x 0.0774= 195 gallons2,293 lb x 1.1 x 0.0774= 195 gallonsglucanglucan ethanol/acreethanol/acre
from cellulosefrom cellulose
Enzymes- currently too expensive
H2OGlucose
Ethanol- loam soilEthanol- loam soil
Ethanol yield from corn with 160 Ethanol yield from corn with 160 lb N averaged 574 gal/acrelb N averaged 574 gal/acre
Ethanol yield from sweet sorghum Ethanol yield from sweet sorghum with 60 lb N averaged 528 with 60 lb N averaged 528 gal/acre from sugar assuming gal/acre from sugar assuming 90% efficiency. 90% efficiency.
Max including glucan= 782 Max including glucan= 782 gal/acregal/acre Corn ethanol estimated 2.8 gal per bushel
Less Productive Soils- Less Productive Soils- 20082008
Lb NLb N ClayClay SandSand
00 1919 3737
4040 3737 6666
8080 5555 8383
120120 5050 104104
160160 7474 9696
200200 8585 109109
240240 6666 102102
Lb NLb N ClayClay SanSandd
00 2424 1818
2020 2424 1616
4040 2828 2121
6060 3939 1818
8080 3737 2222
100100 3434 2626
120120 3838 2121
Corn -bushels Sorghum- wet ton
Preliminary SummaryPreliminary Summary
Prime corn land should remain in Prime corn land should remain in corn production to supply food and corn production to supply food and feed.feed.
Sweet sorghum niche for ethanol Sweet sorghum niche for ethanol production may be on marginal production may be on marginal soils such as heavy clay and sand.soils such as heavy clay and sand.
Because of high cost of cellulose Because of high cost of cellulose enzymes other uses for bagasse enzymes other uses for bagasse should be explored.should be explored.
www.plantsci.missouri.edu/deltacrops
