Yield and Agricultural Input Assumptions Used in Analysis

Available napiergrass studies/data suggest a range of values for napiergrass inputs that will vary based on location, soil quality, and other economic and environmental factors.

For the purposes of this analysis we used high-end estimates. Therefore these values may differ from actual application rates in a given location.

Category

Yield (Current) 4.5-5 dry ton/acre 14-18 dry ton/acre

Yield (Projected) 6.59 dry ton/acre 18-23 dry ton/acre

Nitrogen Fertilizer 100 lbs/acre 15.2 lbs/dry ton 200 lbs/acre 10.0 lbs/dry ton

Phosphorus Fertilizer 40 lbs/acre 6.1 lbs/dry ton 22 lbs/acre 1.1 lbs/dry ton

Potassium Fertilizer 40 lbs/acre 6.1 lbs/dry ton 80 lbs/acre 4.0 lbs/dry ton

Herbicide 0.01 lbs/acre 0.002 lbs/dry ton 7 lbs/acre 0.4 lbs/dry ton

Insecticide 0.1-0.2 lbs/acre 0.0228 lbs/dry ton 0 lbs/acre 0 lbs/dry ton

Lime 0 lbs/acre 0.0 lbs/dry ton 2000 lbs/acre 100.0 lbs/dry ton

Diesel 2.8-3.0 gal/acre 0.4 gal/dry ton 25 gal/acre 1.3 gal/dry ton

Electricity (irrigation) 0 kwh/acre 0.0 kWh/dry ton 499 kWh/acre 25.0 kWh/dry ton

1

Switchgrass sources: 2022 Nat'l Avg RFS2 Control Case (FASOM); 2010 Beach et al

2

Assumes switchgrass yield of 6.59 dry tons/acre in 2022.

3

Assumes napiergrass yield of 19.5 dry tons/acre in 2022.

4

Napiergrass References:

Woodard, K.R., Prine, G.M., Bates, D.B., Chynoweth, D.P. 1991. Preserving elephantgrass and energycane biomass as silage for energy. Bioresource Technology , 36, 253-259.

Woodard, K.R. and Sollenberger L.E. 2008. Production of biofuel crops in Florida: elephantgrass. University of Florida IFAS Extension. SS AGR 297.

Cutts, G., Lee, R., Grey, T., Tubbs, S., Vencill, W., Webster, T., Anderson, W., Herbicide Effect on Napiergrass (Pennisetum Purpureum Schum.) Establishment. Plant Management Network. Draft for Peer Review. April 2010.

Switchgrass1 Napiergrass

per acre per try ton2per acre per dry ton3
mic and environmental factors.

Napiergrass Data Sources4/Notes

Woodard and Sollenberger 2008

Based on 2% annual yield growth; analysis assumes average of 20 dry 

tons/acre

Based on USDA preliminary fields trials : 3 lbs/acre atrazine, 2.5 

lbs/acre pendimethalin, 0.75 lbs/acre glyphosate, and 0.75 lb/acre 

other hericide(s) (Cutts et al 2010). Rates based on active ingredient.

USDA has not seen major insect pests for napiergrass because it is 

high in fiber, therefore not anticipating need for insecticide 

application unless pest emerges.

Lime application is highly dependent on soil pH; discussions with 

USDA suggest that approximately 25% of acreage may need 

application of lime at a rate of 2 tons/acre. This analysis assumes 50% 

of napiergrass acreage requires lime application at 2 tons/acre.

Based on FASOM assumption of 24.8 gal/acre for sugarcane

Based on USDA preliminary estimate of 1.1 acre feet of irrigation, (0.5 

inches per week for 6 months if little/no rainfall and therefore actual 

irrigation rates may be lower) and average FASOM electricity 

requirements for irrigation in SE, SC, and SW.

 36, 253-259.

ant Management Network. Draft for Peer Review. April 2010.

Annual fertilizer rates recommended for the Merkeron cultivar 

(Woodard et al 1991).
Emissions Calculations for Biochemical Ethanol

Ethanol yield = 92.3 gal/dry ton

LHV Ethanol = 76000 btu/gal

Category

N2O Emissions* 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 53,583

g CO2eq/

dry ton 

biomass 7,639

Nitrogen Fertilizer 15.2 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 3,291,414

g CO2eq/

ton of 

nitrogen 3,560

Phosphorus Fertilizer 6.1 lbs/dry ton 0.0005 tons of P/lbs of P 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 1,123,159

g CO2eq/

ton of 

phosphate 486

Potassium Fertilizer 6.1 lbs/dry ton 0.0005 tons of K/lbs of K 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 742,546

g CO2eq/

ton of 

potassium 321

Herbicide 0.002 lbs/dry ton 0.0005

tons herbicide/

lbs herbicide 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 23,450,279

gCO2eq/

tons of 

herbicide 3

Pesticide (average across 

regions) 0.0228 lbs/dry ton 0.0005

tons pesticide/

lbs pesticide 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 27,216,587

gCO2eq/

tons of 

pesticide 44

Lime 0.0

lbs/

dry ton -

Diesel 0.4 gal/dry ton 0.13

mmBTU diesel/

gal diesel 0.0108

dry ton biomass/

gallons fuel 1.32E-05

gallons 

fuel/

btu fuel 96,551

gCO2eq/

mmBTU 

diesel 787

Electricity (irrigation) 0.0 kWh/dry ton -

Total 

Emissions 12,840

Category

N2O Emissions* 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 53,239

g CO2eq/

dry ton 

biomass 7,614

Nitrogen Fertilizer 10.0 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 3,291,414

g CO2eq/

ton of 

nitrogen 2,354

Phosphorus Fertilizer 1.1 lbs/dry ton 0.0005 tons of P/lbs of P 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 1,123,159

g CO2eq/

ton of 

phosphate 88

Potassium Fertilizer 4.0 lbs/dry ton 0.0005 tons of K/lbs of K 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 742,546

g CO2eq/

ton of 

potassium 212

Herbicide 0.4 lbs/dry ton 0.0005

tons herbicide/

lbs herbicide 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 23,450,279

gCO2eq/

tonsof 

herbicide 587

Switchgrass Inputs

Napiergrass

Conversions Emissions/mmbtu fuel
Pesticide 0.0 lbs/dry ton -

Lime 100.0 lbs/dry ton 0.0005

ton lime/

lbs lime 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 408,231

gCO2eq/

ton of lime 2,919

Diesel 1.3 gal/dry ton 0.13

mmBTU/

gal diesel 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 96,551

gCO2eq/

mmBTU 

diesel 2,244

Electricity (irrigation) 25.0 kWh/dry ton 0.0034

mmBtu/

kWh 0.0109

dry ton biomass/

gallons fuel 1.31579E-05

gallons 

fuel/

btu fuel 219,824

gCO2eq/

mmBtu 2,677

Total 

Emissions 18,695

Difference 5,855

*Source: IPCC (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Vol. 4: Agriculture, Forestry; and Other Land Use.
gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel 7.6

gCO2eq/mm

btu fuel 2.4

gCO2eq/mm

btu fuel 0.1

 0.2

gCO2eq/mm

btu fuel 0.6

Emissions/mmbtu fuel
gCO2eq/mm

btu fuel 

-

gCO2eq/mm

btu fuel 2.9

gCO2eq/mm

btu fuel 2.2

gCO2eq/mm

btu fuel 2.7

gCO2eq/mm

btu fuel

gCO2eq/mm

btu fuel
Emissions Calculations for Thermochemical Ethanol

Ethanol yield = 74.9 gal/dry ton

LHV Mixed alcohols = 89480 btu/gal

Category

N2O Emissions* 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 53583

g CO2eq/

dry ton 

biomass 7995

gCO2eq/mm

btu fuel

Nitrogen Fertilizer 15.2 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 3291413.998

g CO2eq/

ton of 

nitrogen 3726

gCO2eq/mm

btu fuel

Phosphorus Fertilizer 6.1 lbs/dry ton 0.0005

tons of P/lbs of 

P 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 1123158.905

g CO2eq/

ton of 

phosphate 509

gCO2eq/mm

btu fuel

Potassium Fertilizer 6.1 lbs/dry ton 0.0005

tons of K/lbs of 

K 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 742545.7661

g CO2eq/

ton of 

potassium 336

gCO2eq/mm

btu fuel

Herbicide 0.0015 lbs/dry ton 0.0005

tons 

herbicide/

lbs herbicide 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 23450278.67

gCO2eq/

tons of 

herbicide 3

gCO2eq/mm

btu fuel

Pesticide (average across 

regions) 0.023 lbs/dry ton 0.0005

tons pesticide/

lbs pesticide 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 27216586.75

gCO2eq/

tons of 

pesticide 46

gCO2eq/mm

btu fuel

Lime 0.0

lbs/

dry ton 0

gCO2eq/mm

btu fuel

Diesel 0.4 gal/dry ton 0.13

mmBTU 

diesel/

gal diesel 0.01335113

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 96551.365

gCO2eq/

mmBTU 

diesel 824

gCO2eq/mm

btu fuel

Electricity (irrigation) 0.0 kWh/dry ton 0

Total 

Emissions 13439

gCO2eq/mm

btu fuel

Category

N2O Emissions* 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 53,239

g CO2eq/

dry ton 

biomass 7944

gCO2eq/mm

btu fuel

Nitrogen Fertilizer 10.0 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 3,291,414

g CO2eq/

ton of 

nitrogen 2456

gCO2eq/mm

btu fuel

Phosphorus Fertilizer 1.1 lbs/dry ton 0.0005

tons of P/lbs of 

P 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 1,123,159

g CO2eq/

ton of 

phosphate 92

gCO2eq/mm

btu fuel

Potassium Fertilizer 4.0 lbs/dry ton 0.0005

tons of K/lbs of 

K 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 742,546

g CO2eq/

ton of 

potassium 222

gCO2eq/mm

btu fuel

Herbicide 0.4 lbs/dry ton 0.0005

tons 

herbicide/

lbs herbicide 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 23,450,279

gCO2eq/

tonsof 

herbicide 612

gCO2eq/mm

btu fuel

Switchgrass Inputs

Napiergrass Inputs

Conversions Emissions/mmbtu fuel
Pesticide 0.0 lbs/dry ton 0

gCO2eq/mm

btu fuel

Lime 100.0 lbs/dry ton 0.0005

ton lime/

lbs lime 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 408,231

gCO2eq/

ton of lime 3046

gCO2eq/mm

btu fuel

Diesel 1.3 gal/dry ton 0.13

mmBTU/

gal diesel 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 96,551

gCO2eq/

mmBTU 

diesel 2341

gCO2eq/mm

btu fuel

Electricity (irrigation) 25.0 kWh/dry ton 0.0034

mmBtu/

kWh 0.0134

dry ton 

biomass/

gallons fuel 1.11757E-05

gallons 

fuel/

btu fuel 219,824

gCO2eq/

mmBtu 2792

gCO2eq/mm

btu fuel

Total 

Emissions 19504

gCO2eq/mm

btu fuel

Difference 6065

gCO2eq/mm

btu fuel

*Source: IPCC (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Vol. 4: Agriculture, Forestry; and Other Land Use.
Emissions Calculations for F-T Diesel

Ethanol yield = 58.6 gal/dry ton

F-T diesel LHV 115439 btu/gallon

Category

N2O Emissions* 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 53,583

g CO2eq/

dry ton 

biomass 7,921

Nitrogen Fertilizer 15.2 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 3,291,414

g CO2eq/

ton of 

nitrogen 3,692

Phosphorus Fertilizer 6.1 lbs/dry ton 0.0005

tons of P/lbs of 

P 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 1,123,159

g CO2eq/

ton of 

phosphate 504

Potassium Fertilizer 6.1 lbs/dry ton 0.0005

tons of K/lbs of 

K 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 742,546

g CO2eq/

ton of 

potassium 333

Herbicide 0.0015 lbs/dry ton 0.0005

tons 

herbicide/

lbs herbicide 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 23,450,279

gCO2eq/

tons of 

herbicide 3

Pesticide (average across 

regions) 0.023 lbs/dry ton 0.0005

tons pesticide/

lbs pesticide 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 27,216,587

gCO2eq/

tons of 

pesticide 46

Lime 0.0

lbs/

dry ton -

Diesel 0.4 gal/dry ton 0.13

mmBTU 

diesel/

gal diesel 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 96,551

gCO2eq/

mmBTU 

diesel 817

Electricity (irrigation) 0.0 kWh/dry ton -

Total 

Emissions 13,315

Category

N2O Emissions* 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 53,239

g CO2eq/

dry ton 

biomass 7,870

Nitrogen Fertilizer 10.0 lbs/dry ton 0.0005

tons of 

nitrogen/lbs of 

nitrogen 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 3,291,414

g CO2eq/

ton of 

nitrogen 2,433

Phosphorus Fertilizer 1.1 lbs/dry ton 0.0005

tons of P/lbs of 

P 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 1,123,159

g CO2eq/

ton of 

phosphate 91

Potassium Fertilizer 4.0 lbs/dry ton 0.0005

tons of K/lbs of 

K 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 742,546

g CO2eq/

ton of 

potassium 220

Switchgrass Inputs

Energy Cane Inputs

Conversions Emissions/mmbtu fuel
Herbicide 0.4 lbs/dry ton 0.0005

tons 

herbicide/

lbs herbicide 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 23,450,279

gCO2eq/

tonsof 

herbicide 607

Pesticide 0 lbs/dry ton -

Lime 100.0 lbs/dry ton 0.0005

ton lime/

lbs lime 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 408,231

gCO2eq/

ton of lime 3,017

Diesel 1.3 gal/dry ton 0.13

mmBTU/

gal diesel 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 96,551

gCO2eq/

mmBTU 

diesel 2,319

Electricity (irrigation) 25.0 kWh/dry ton 0.0034

mmBtu/

kWh 0.01706485

dry ton 

biomass/

gallons fuel 8.66258E-06

gallons 

fuel/

btu fuel 219,824

gCO2eq/

mmBtu 2,766

Total 

Emissions 19,323

Difference 6,009

*Source: IPCC (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Vol. 4: Agriculture, Forestry; and Other Land Use.
gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

Emissions/mmbtu fuel
gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel

gCO2eq/m

mbtu fuel
Napiergrass

Fuel Type Biochemical Thermo-chemical

Net Domestic Agriculture (w/o land use change) 12 12 

Net International Agriculture (w/o land use change) 0 0

Domestic Land Use Change -2 -3

International Land Use Change, Mean 15 16

Mean (Low/High) (9/23) (9/24)

Fuel Production -33 4

Fuel and Feedstock Transport 3 3

Tailpipe Emissions 1 1

Total Emissions, Mean -4 33

% Reduction, Mean 104% 66%

Switchgrass

Fuel Type Biochemical Thermo-chemical

Net Domestic Agriculture (w/o land use change) 6 6

Net International Agriculture (w/o land use change) 0 0

Domestic Land Use Change -2 -3

International Land Use Change, 

Mean (Low/High)

Fuel Production -33 4

Fuel and Feedstock Transport 3 3

Tailpipe Emissions 1 1

Total Emissions, Mean (Low/High) -10 (-17/-2) 27 (20/35)

15 (9/23) 16 (9/24)
F-T diesel

 12

0

-3

16

 (9/24)

5

3

1

34

65%

F-T diesel

6

0

-3

5

3

1

29 (22/37)

16 (9/24)
Hemicellulose 21.1 % on dry basis

Aden et al. 

2002 25% % on dry basis

Cellulose 37.4 % on dry basis

Aden et al. 

2002 37% % on dry basis

Lignin 18 % on dry basis

Aden et al. 

2002 21% % on dry basis

Switchgrass Napiergrass
Estimate from BP 

petition
N2O Equations and Factors

Source: IPCC (2006). 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Vol. 4: Agriculture, Forestry; and Other L

Direct N2O Emissions

Direct Emissions (Overall Equation)

Emissions =

EF for N additions from mineral fertilizer and crop residues =

N Additions from Mineral Fertilizers

N additions to soils from mineral fertilizers =

N Additions from Crop Residues

N additions to soils from crop residues =

where,

Above-ground residue dry matter =

Crop residue summary equation [see Crop Residue Defaults tab fro explanation of letters]

N additions to soils from crop residues =

Indirect N2O Emissions

Note that for indirect emissions, the calculation of N applied to soils from fertilizers or crop residues is the same as for direct em

Indirect Emissions from Volatilization

Emissions =

N lost (from synthetic fertilizer additions) through volatilization =

EF for N lost through volatilization =

Indirect Emissions from Leaching/Runoff

Emissions =

N lost through leaching/runoff (from all N sources) =

EF for N lost through leaching/runoff =

Yield assumptions:

Napiergrass 20 dry tons/acre = 44800 kg/ha

Switchgrass: 6.59 dry tons/acre = 14773.01 kg/ha
nhouse Gas Inventories. Vol. 4: Agriculture, Forestry; and Other Land Use.

Equation

(N additions to soils from mineral fertilizer + N additions to soils from 

crop residues) × EF (336+330.6)*0.01 6.666 kg N20-N

0.01 kg N2O-N / kg N added

kg fertilizer N applied to soils (i.e., change in fertilizer N applications 

between current and projected year) 336 kg/ha

above-ground residue dry matter × Crop Area × [N content of 

aboveground residues + ratio of belowground residues to harvested 

yield for crop × N content of belowground residues]

13440 kg/ha × 1 

ha × [0.015 + 0.80 

× 0.012] 330.6 kg

Fresh weight yield (kg fresh weight harvested/ha) × dry matter 

fraction of harvested crop × slope + intercept

44800 kg/ha x 0.3 

+ 0 13440 kg/ha

 Defaults tab fro explanation of letters]

(B / A × C × D + E) × A × (F + G × H)

 soils from fertilizers or crop residues is the same as for direct emissions

Equation

N additions to soils from mineral fertilizers × N lost through 

volatilization × EF 336*0.1*0.01 0.336 kg N2O-N

0.1 (kg NH3–N + NOx–N) / kg N applied

0.010 kg N2O–N / (kg NH3–N + NOX–N volatilised)

Equation

(N additions to soils from mineral fertilizers + N additions to soils 

from crop residues) × N lost through leaching or runoff × EF

(336+330.6)*0.3*0

.0075 1.5 kg N2O-N

0.3 N losses by leaching or runoff / kg N addition

0.0075 kg N20-N / kg N leaching or runoff

TOTAL (per ha) 8.502 kg N2O-N/ha

2636 kg CO2eq/ha

1065 kg CO2eq/acre

53.24 kg CO2eq/dry ton biomass

53239 g CO2eq/dry ton biomass

Napiergrass
(112+109.02)*0.01 2.2102 kg N20-N

112 kg/ha

4431.9 kg/ha × 1 ha 

× [0.015 + 0.80 × 

0.012] 109.02 kg 

14773.012 kg/ha x 

0.3 + 0 4431.9 kg/ha

112*0.1*0.01 0.112 kg N2O-N

(112+109.02)*0.3*0

.0075 0.4973 kg N2O-N

kg N2O-N/ha 2.8195 kg N2O-N

kg CO2eq/ha 874.04 kg CO2eq/ha

kg CO2eq/acre 353.11 kg CO2eq/acre

kg CO2eq/dry ton biomass 53.583 kg CO2eq/dry ton biomass

g CO2eq/dry ton biomass 53583 g CO2eq/dry ton biomass

Switchgrass
Table 11.2 DEFAULT FACTORS FOR ESTIMATION OF N ADDED TO SOILS FROM CROP RESIDUES a 

A B C D E F G H

Crop Crop Area

Crop 

Harvested

Dry matter 

fraction of 

harvested 

product 

(DRY) 

N content 

of aboveground 

residues 

(NAG) 

Ratio of 

belowground 

residues to 

aboveground 

biomass 

(RBG-BIO) 

N content 

of belowground 

residues 

(NBG) 

Slope 

± 2 s.d. as 

% of mean Intercept 

± 2 s.d. as 

% of mean R

2

 adj. 

Units ha kg

Major crop types 

Grains 0.88 1.09 ± 2% 0.88 ± 6% 0.65 0.006 0.22 0.009

Beans & pulsesb 0.91 1.13 ± 19% 0.85 ± 56% 0.28 0.008 0.19 0.008

Tubersc 0.22 0.10 ± 69% 1.06 ± 70% 0.18 0.019 0.20 0.014

Root crops, otherd 0.94 1.07 ± 19% 1.54 ± 41% 0.63 0.016 0.20 0.014

N-fixing forages 0.90 0.30 ± 50% default 0.00 - - 0.027 0.40 0.022

Non-N-fixing forages 0.90 0.30 ± 50% default 0.00 - - 0.015 0.54 0.012

Perennial grasses 1 0.90 0.30 ± 50% default 0.00 - - 0.015 0.80 0.012

Grass-clover mixtures 0.90 0.30 ± 50% default 0.00 - - 0.025 0.80 0.016

Individual crops 

Maize 0.87 1.03 ± 3% 0.61 ± 19% 0.76 0.006 0.22 0.007

Wheat 0.89 1.51 ± 3% 0.52 ± 17% 0.68 0.006 0.24 0.009

Rice 0.89 0.95 ±19% 2.46 ± 41% 0.47 0.007 0.16 NA 

Barley 0.89 0.98 ± 8% 0.59 ± 41% 0.68 0.007 0.22 0.014

Oats 0.89 0.91 ± 5% 0.89 ± 8% 0.45 0.007 0.25 0.008

Millet 0.90 1.43 ± 18% 0.14 ± 308% 0.50 0.007 NA NA 

Sorghum 0.89 0.88 ± 13% 1.33 ± 27% 0.36 0.007 NA 0.006

Ryee

0.88 1.09 ± 50% default 0.88 ± 50% default - 0.005 NA 0.011

Soybeanf

0.91 0.93 ± 31% 1.35 ± 49% 0.16 0.008 0.19 0.008

Dry beang

0.90 0.36 ± 100% 0.68 ± 47% 0.15 0.010 NA 0.010

Potatoh

0.22 0.10 ± 69% 1.06 ± 70% 0.18 0.019 0.20 0.014

Peanut (w/pod)i 0.94 1.07 ± 19% 1.54 ± 41% 0.63 0.016 NA NA 

Alfalfaj

0.90 0.29 ± 31% 0.00 - - 0.027 0.40 0.019

Non-legume hayj 0.90 0.18 ± 50% default 0.00 - - 0.150 0.54 0.012

Oil Palm 0.012

Above-ground residue dry matter AGDM(T) (Mg/ha): AGDM(T) 

= Crop(T) * slope(T) + intercept(T) 
Items highlighted indicate crops where NA data has been pulled from crop categories to estimate N2O emissions in the Crop Residues N worksheet

a Source: Literature review by Stephen A. Williams, Natural Resource Ecology Laboratory, Colorado State University. (Email: stevewi@warnercnr.colostate.edu) for CASMGS (http://www.casmgs.co

of the original references is given in Annex 11A.1.

b The average above-ground residue:grain ratio from all data used was 2.0 and included data for soya bean, dry bean, lentil, cowpea, black gram, and pea.

c Modelled after potatoes.

d Modelled after peanuts.

e No data for rye. Slope and intercept values are those for all grain. Default s.d.

f The average above-ground residue:grain ratio from all data used was 1.9.

g Ortega, 1988 (see Annex 11A.1). The average above-ground residue:grain ratio from this single source was 1.6. default s.d. for root:AGB.

h The mean value for above-ground residue:tuber ratio in the sources used was 0.27 with a standard error of 0.04.

I The mean value for above-ground residue: pod yield in the sources used was 1.80 with a standard error of 0.10.

j Single source. Default s.d. for root:AGB.

k This is the average above-ground biomass reported as litter or harvest losses. This does not include reported stubble, which averaged 0.165 x Reported Yields. Default s.d.

l Estimate of root turnover to above-ground production based on the assumption that in natural grass systems below-ground biomass is approximately equal to twice (one to three times) the above-g

root turnover in these systems averages about 40% (30% to 50%) per year. Default s.d.

m This is an estimate of non-tuber roots based on the root:shoot values found for other crops. If unmarketable tuber yield is returned to the soil then data are derived from Vangessel and Renner, 19

(unmarketable yield = 0.08 * marketable yield = 0.29 * above-ground biomass) suggest that the total residues returned might then be on the order of 0.49 * above-ground biomass. Default s.d.

n This is an estimate of root turnover in perennial systems. Default s.d.

p It is assumed here that grass dominates the system by 2 to 1 over legumes.

Khalid, H; ZZ Zin, and JM Anderson. "Decomposition Processes and Nutrient Release Patterns of Oil Palm Residues." Journal of Oil Palm Research Vol. 12 No. I, June 2000, p. 46-63

http://palmoilis.mpob.gov.my/publications/joprv12n1-46.pdf

TABLE 1. RESOURCE QUALITY CHARACTERISTICS OF FRESH OIL PALM RESIDUES 

Nutrient Leaflet Rachis Trunk Root 

N 2.66 0.44 0.58 0.41

P 0.15 0.05 0.06 0.04

K 1.33 1.8 1.86 0.9

Ca 0.62 0.55 0.38 0.07

Mg 0.26 0.17 0.15 0.11

SiO, 1.55 0.39 0.84 0.52

C 47.91 47.34 47.77 48

C/N ratio 18 107 82 117

Lignin 24.96 20.96 18.14 23.77

Lignin/N ratio 9.38 47.64 31.28 57.98

Holocellulose 69.86 73.85 83.06 67.39

%

for CASMGS (http://www.casmgs.colostate.edu/). A list

ce (one to three times) the above-ground biomass and that

ved from Vangessel and Renner, 1990 (see Annex 11A.1)

ground biomass. Default s.d.

 I, June 2000, p. 46-63