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Balancing Biomass for Bioenergy and Conserving the Soil Resource. Jane Johnson USDA-ARS- North Central Soil Conservation Research Laboratory. Introduction. Energy paradigm is changing from petroleum to mixed renewable Sufficient energy available, but in diffuse form - PowerPoint PPT Presentation
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Balancing Biomass for Balancing Biomass for Bioenergy and Conserving Bioenergy and Conserving
the Soil Resourcethe Soil Resource
Jane JohnsonJane JohnsonUSDA-ARS-USDA-ARS-
North Central Soil Conservation North Central Soil Conservation Research LaboratoryResearch Laboratory
USDA-ARS
IntroductionIntroduction
Energy paradigm is changing from Energy paradigm is changing from petroleum to mixed renewablepetroleum to mixed renewable
Sufficient energy available, but in Sufficient energy available, but in diffuse formdiffuse form
Can we be sustainable or at least Can we be sustainable or at least minimize environmental footprint?minimize environmental footprint?
Can we balance food, feed, fiber and Can we balance food, feed, fiber and fuel?fuel?
USDA-ARS
OutlineOutline
BackgroundBackground Discuss roles of non-grain biomassDiscuss roles of non-grain biomass Constraints for harvest ratesConstraints for harvest rates ExamplesExamples SummarySummary
USDA-ARS
Cellulosic biomassCellulosic biomass
NRCS plant material center
USDA-ARS
Cellulosic ethanol – sugar platform Cellulosic ethanol – sugar platform Thermochemical – controlled combustionThermochemical – controlled combustion
GasificationGasification Dimethylether (DME)Dimethylether (DME) Replace natural gasReplace natural gas
PyrolysisPyrolysisBio oil, bio char, biogasBio oil, bio char, biogas
Other bio-based products Other bio-based products
Interest in biomass for bioenergyInterest in biomass for bioenergy
USDA-ARS
Agriculture – 998 million tonsAgriculture – 998 million tons Perennial energy crops – 377 million tonsPerennial energy crops – 377 million tons ““Wastes” – 87 million tonsWastes” – 87 million tons Grain – 87 million tonsGrain – 87 million tons Crop residues – 428 million tonsCrop residues – 428 million tons
Corn stover – 256 million tonsCorn stover – 256 million tons
Forestry – 368 million tons
(projected estimates; Billion Ton Report, Perlack et al 2005)(projected estimates; Billion Ton Report, Perlack et al 2005)
Biomass for bioenergyBiomass for bioenergy
USDA-ARS
BenefitsBenefits RenewableRenewable Domestic Domestic Reduces release of Reduces release of
fossil COfossil CO22
Additional farm Additional farm commoditycommodity
RisksRisks Decreased surface Decreased surface
residuesresidues Increased erosionIncreased erosion
Off-site nutrient and Off-site nutrient and sedimentssediments
Decreased SOMDecreased SOM Decreased productivityDecreased productivity Other – loss of winter Other – loss of winter
cover, habitatcover, habitat
Biomass harvest
USDA-ARS
Primary roles of non-grain biomassPrimary roles of non-grain biomass
Protect the soil from erosion Protect the soil from erosion
USDA-ARS
Water
USDA-NRCSMorris, MN 2003
Wakeeney, KSL. Kucerik, 2004
LaPorte, IN 2004
Wind
Tillage
MN, D. Reicosky
http://www.umanitoba.ca
USDA-ARS
Primary roles of crop biomassPrimary roles of crop biomass
Protect the soil from erosion Protect the soil from erosion
Provide C and other organic inputs to Provide C and other organic inputs to support the below ground ecosystem support the below ground ecosystem
USDA-ARS
USDA-ARS
Primary roles of crop biomass Primary roles of crop biomass
Protect the soil from erosion Protect the soil from erosion Provide C and other organic inputs to support the below Provide C and other organic inputs to support the below
ground ecosystem ground ecosystem
Build and maintain soil organic matter/soil Build and maintain soil organic matter/soil organic carbonorganic carbon
USDA-ARS
Biomass management for Biomass management for Carbon (C) storageCarbon (C) storage
Storing C in soil – building humusStoring C in soil – building humus Nutrient cyclingNutrient cycling Water holding capacityWater holding capacity Improve soil aggregationImprove soil aggregation Maintain soil productivityMaintain soil productivity
Remove CORemove CO22 from atmosphere from atmosphere
USDA-ARS
Biomass management for C Biomass management for C storagestorage
C inputs > C outputs = increased SOCC inputs > C outputs = increased SOC
C InputsC Inputs Crop above Crop above
ground biomassground biomass Crop root and Crop root and
their exudatestheir exudates ManureManure
C OutputsC Outputs Respired CRespired C Erosion Erosion Tillage Tillage LeachingLeaching HarvestHarvest
USDA-ARS
So
il C
arb
on
Co
nte
nt //
Soil C Change with ManagementIntensive Ag begins
Management Changes
Stover removal
Offsetting Practices (no till, cover crops, diverse rotations, etc.)
No Offsetting Practices
Time
Credit: Wally Wilhelm, Dec. 2005
?
So
il C
arb
on
Co
nte
nt //
Soil C Change with ManagementIntensive Ag begins
Management Changes
Stover removal
Offsetting Practices (no till, cover crops, diverse rotations, etc.)
No Offsetting Practices
Time
Credit: Wally Wilhelm, Dec. 2005
?
USDA-ARS
““The need to maintain soil productivity The need to maintain soil productivity should be our first consideration and only, should be our first consideration and only, once this criterion has been met, should once this criterion has been met, should crop biomass be removed for alternative crop biomass be removed for alternative purposes.”purposes.”
William (Bill) Larson, 1979William (Bill) Larson, 1979
USDA-ARS
Minimum biomass inputs Minimum biomass inputs depends ondepends on
Precipitation and temperaturePrecipitation and temperature CropCrop Crop rotationCrop rotation TillageTillage Nutrient managementNutrient management Additional inputsAdditional inputs Limiting constraint (erosion or Limiting constraint (erosion or
carbon)carbon)
USDA-ARS
USDA-ARS Renewable Energy Assessment Project (REAP) Team Locations
USDA-ARS
REAP goals REAP goals
Determine how much biomass needs Determine how much biomass needs to stay on the land to protect soil to stay on the land to protect soil resourceresource
Compare short- and long-term Compare short- and long-term economics of using biomass economics of using biomass feedstock and soil organic inputfeedstock and soil organic input
Provide recommendations and Provide recommendations and guidelines for sustainable biomass guidelines for sustainable biomass harvestharvest
USDA-ARS
How much biomass needs to stay How much biomass needs to stay in the field?in the field?
Prevent erosionPrevent erosion Sustain belowground ecosystemSustain belowground ecosystem Build soil organic matterBuild soil organic matter Sequester CSequester C Maintain productivityMaintain productivity
USDA-ARS
ConstraintsConstraints
ErosionErosion Reduces Reduces
productivityproductivity Degrades soilDegrades soil Degrades water Degrades water
qualityquality Amount as % Amount as %
surface coversurface cover
Soil organic matterSoil organic matter Reduces Reduces
productivityproductivity Reduces water Reduces water
holding capacityholding capacity Degrades soilDegrades soil Contributed to Contributed to
increased atm increased atm COCO22
Total inputsTotal inputs
USDA-ARS
Harvestable Stover based on erosion constraints and (1995-2000) corn management practices Region Avg. corn
yld Percentage Removed
Stover Collected
Stover Left
Bu acre-1 % Tons acre-1 IA-MN 143 67.7 2.30 1.1 IL-IN 139 60.6 1.99 1.3 NE-Platte River
143 41.4 1.39 2.0
Based on Graham et al. 2007 AJ 99:1-11
USDA-ARS
Minimum inputs estimated by a simple linear relationship
bxay
• y is change in soil organic carbon change • x is the amount of C (or biomass) input annually
Larson et al., 1972; Paustian et al., 1997; Follett et al., 2005; Johnson et al., 2006
USDA-ARS
Critical biomass inputsLarson et al., 1972
y = 5.55x - 13.25R2 = 0.975
-15
-10
-5
0
5
10
15
20
25
30
0 2 4 6 8
Aboveground inputston/acre
% c
ha
ng
e i
n C
USDA-ARS
Estimated minimum biomass inputs to prevent loss of SOC Crop Rotation Tillage Minimum
biomass Cover
Ton acre-1 % Corn continuous MBP 3.39 5 Corn-soybean MBP 5.58 5 Corn continuous Chisel/NT 2.36 30-85 Corn-soybean Chisel/NT 3.52 30-85 Johnson et al (2006) JSWC 61(4) 121A-125A; Johnson et al (2006) AJ 98:622-636
USDA-ARS
Maximum county average 2006 yield Corn
yield Biomass
yield Min.
biomass In
field Harvested
States Bu a-1 Ton a-1 % % IA 193.0 4.07 2.36 57.9 42.1 MN 181.0 3.82 2.36 61.8 38.2 IN 178.6 3.77 2.36 62.6 37.4 IL 181.0 3.82 2.36 61.8 38.2 USDA-NASS; Johnson et al (2006) JSWC 61(4) 121A-125A; Johnson et al (2006) AJ 98:622-636
Example, assumes conservation tillage and continuous corn
USDA-ARS
Sto
ver
to r
eta
in (
Mg
ha-1)
0
5
10
15
20
Sto
ver
to r
eta
in (
ton
ac
re-1)
0
2
4
6
8Soil Organic CarbonWater ErosionWind Erosion
Continuous corn Corn-soybean
Moldboardplow
No orconserv.
tillage
Moldboardplow
No orconserv.
tillage
7.58
3.11
1.73
5.25
12.50
7.90
0.65
7.98
0.960.14
2.74
0.15
Wilhelm et al., 2007, AJ
USDA-ARSGrain yield (Mg ha-1)
5 10 15 20 25
Har
vest
able
sto
ver
(Mg
ha-1
)
-5
0
5
10
15
20
Grain yield (bu acre-1)
100 150 200 250 300 350 400
Har
vest
able
sto
ver
(to
n a
cre-1
)
-2
0
2
4
6
8C-C, No or conserv. tillageC-C, Moldboard plowC-S, No or conserv. tillageC-S, Moldboard plow
Wilhelm et al, 2007 AJ
USDA-ARS
Products:Products: Guidelines for crop and soil management Guidelines for crop and soil management
to ensure sustainable harvestto ensure sustainable harvest Predictive tools for crop biomass harvestPredictive tools for crop biomass harvest Tools to assess short and long-term Tools to assess short and long-term
trade-offs (environmental and economic)trade-offs (environmental and economic)
Outcome: Outcome: Biomass energy industry based on Biomass energy industry based on
sustainable management practices.sustainable management practices.
USDA-ARS
Current projectsCurrent projects
Biomass removal studyBiomass removal study Tillage: Tillage:
No Till (Established 1995)No Till (Established 1995) No Till (Established 2005)No Till (Established 2005) Chisel Plow, spring diskChisel Plow, spring disk
Removal rates: 0, 50, 75 Removal rates: 0, 50, 75 and 100% of rowsand 100% of rows
Monitor: biomass produced, Monitor: biomass produced, returned, soil carbon (0-returned, soil carbon (0-100 cm), yield100 cm), yield
USDA-ARS
Carbon Crop StudyCarbon Crop StudyEstablished 2000, modified 2007Established 2000, modified 2007
No tillageNo tillage
TRT Rotation 1 Switchgrass - spring harvest 2 Switchgrass - autumn harvest 3 Corn + winter rye/Forage Soybeans + Winter Lentils/Wheat + Hairy Vetch 4 Wheat + Hairy Vetch/Corn + winter rye/ Forage Soybeans + Winter Lentils 5 Corn/Soybean/Wheat + Alfalfa/Alfalfa/Alfalfa 6 Soybean/Corn 7 Big Bluestem spring harvest 8 Big Bluestem autumn harvest 9 Forage Soybeans + Winter Lentils/Wheat + Hairy Vetch /Corn + winter rye
10 Big Bluestem + clover (autumn harvest) 11 Alfalfa/Corn/Soybean/Wheat + Alfalfa/Alfalfa/Alfalfa 12 Switchgrass + clover (autumn harvest)
USDA-ARS
Related issuesRelated issues
No perfect solutionNo perfect solution Fossil fuel – finite, huge environmental Fossil fuel – finite, huge environmental
footprintfootprint Water to grow cropWater to grow crop Water for conversion – energy Water for conversion – energy
platform dependentplatform dependent Off-site impacts of nutrients/pesticidesOff-site impacts of nutrients/pesticides Habitat Habitat
USDA-ARS
Its about the future: finding balance