Ann C. WilkieSoil and Water Science Department

University of Florida-IFAS

acwilkie@ufl.edu

Midwest Manure Summit

Lambeau Field, Green Bay, Wisconsin

February 16, 2011

Ecological Impacts on Future Farming

Fossil

Fuel

Cycle

CO2

Millions of years

Millions of years

Photosynthesis

exceeds

decomposition

Time, heat, pressure

Millions of years

Organic Matter Buried

under Sediments

Oil

CoalGas

CO2

About 100 years

Natural Resources

Waste

Greenhouse Gases

Biodiversity

EnergyHuman Health

Water

The Dimensions of Sustainability

Community

IMPACTS OF GLOBAL WARMING

• Climate change – shorter, warmer winters, earlier springs, changes in rainfall patterns, hotter temperatures affect growing seasons and animal health

• Plant health – many species are vulnerable to warmer temperatures and will respond differently to higher CO2 concentrations

• Wildlife – habitats may be transformed, degraded, or destroyed

• Human health – a warmer climate makes it easier for disease-bearing insects (ticks, mosquitoes) to spread and reproduce

ISSUES FACING FARMS

OF THE FUTURE

• Environmental regulations

– Water quality

– Air quality

– Odor

• Increasing cost of energy

• Some actions that address climate

change issues are simply good

management practices, such as:

– Efficient manure use

– Farm energy efficiency

– Cover cropping

– Development of local markets

NUTRIENT MANAGEMENT

• Land application is the most

sustainable option for manure nutrients

• Nitrogen

– Haber-Bosch process is energy intensive

• Phosphorus

– Finite resource

Steam

reformin

g

Source: wikipedia.com (http://en.wikipedia.org/wiki/File:Haber-Bosch-En.svg)

Haber-Bosch process for the production of Ammonia

Phosphate MiningSource: http://cdn.wn.com/pd/fb/2c/21c0d2bd610bbea9a2cae5319c20_large.jpg

Source: http://seekingalpha.com/article/182522-taking-stock-of-phosphorus-and-biofuels

Dairy Express

Nitrogen & Phosphorus

• Nutrient management plans

• Export excess – Where?

• Manure application for bioenergy crops?

• Fugitive nutrients– Wild algae

• Farmed algae– Domesticated algae

Matching Manure Nutrients to Crop Needs:

Feed Management

• Eliminating excessive phosphorus

and nitrogen in dairy cow feed

provides a cost savings by reducing

unnecessary supplements and

leads to decreased concentrations

of nutrients in manure.

• This approach is suitable for all

regions and dairies of all sizes.

• Eliminating excess crude protein (a major source of nitrogen) in cow

diets can decrease air emissions of ammonia.

• Dairy cows are typically fed 20-25% more phosphorus than

recommended by NRC. Reducing dietary phosphorus intake provides

major environmental benefits while saving producers money.

Phosphorus in dairy diets vs. NRC recommended levels (NRC, 2001)

Matching Manure Nutrients to Crop Needs:

Feed Management

Human-related Sources of Methane in the United States(% of total methane emissions)

• Unlike other greenhouse gases, methane can be used to produce energy since it is the major component (95%) of natural gas.

• Consequently, for many methane sources, opportunities exist to reduce emissions by capturing the methane and using it as fuel.

Electrical and/or

thermal energy

Biofertilizer

Organic

wastes Anaerobic

digestionBiogas

Solar energy

Animal husbandry

Biofuel production

Crop harvesting

Industrial processing

Human consumption

Photosynthesis

H2O

CO2

Biogas Cycle

Energy

crops

Natural gas

pipeline

Methanogenesis

Complex Organic Carbon

Monomers & Oligomers

Organic Acids

Acetate – H2 / CO2

CH4 + CO2

Hydrolysis

Acidogenesis

Acetogenesis

Anaerobic Digestion

COMPLEX

ORGANIC

MATTER

SIMPLE

ORGANICS

ACETATE

H2

/ CO2

METHANE and CARBON DIOXIDE

LOW ODOR EFFLUENT

LIQUEFACTION

PHASE

GASIFICATION

PHASE

ACIDOGENS METHANOGENS

STORAGE versus TREATMENT

• Unbalanced fermentation

• Intermediate metabolite accumulation

• Malodor

• Balanced fermentation

• Waste stabilization

• Permanent odor reduction

Benefits of Anaerobic Digestion

• Renewable energy

• BOD/COD reduction

• Odor reduction

• Pathogen reduction

• Nutrient conservation

• Greenhouse gas reduction

Odor Controland

Greenhouse Gas Mitigation

National Biodigester Programme

Cambodia (July 2010)

Biogas Burner – Cambodia (July 2010)

Renewable energy use reduces

CO2 pollution from fossil-fueled

power plants

More electricity from farm methane= Less electricity from fossil fuels= CO2 emission reductions

Electrical Grid

Anaerobic Digesters in the

U.S. Livestock Market

• 157 operating digesters

– 126 on dairies

– 24 on hog operations

Source: U.S. Environmental Protection Agency, U.S. Anaerobic Digester Status Report, October 2010.

Feedstocks

• Animal manures

• Agro-Industrial wastewaters

• Municipal wastewaters

• Municipal solid wastes

• Biofuels by-products

• Energy crops / crop residues

Gases

Kerosene

Gasoline

Diesel

Engine Oil

Fuel Oil

Tarmac

Crude Oil

Oil Refinery

Biogas

Manure

Fibrous

Solids

Liquid

Cellulose Biofuel

Peat substitute

Compost

Gasification

AnaerobicDigestion

Biofertilizer

Crops

AlgaePress cake

Oil Biodiesel

Methane

Electricity

Animal feed

Manure Biorefinery

Solids Separation

Biofuels

• The rapid growth in biofuels production

has significant impacts that must be

managed:

– Energy demand

– Wastewater production

– Water and Land use

– Air emissions

• Larger facilities mean increased

wastewater and by-product volumes

CLOSED

LOOP

DAIRY / FEEDLOT BIOETHANOL PLANT

ANAEROBIC DIGESTER

MANURE BIOGAS

FEED

STILLAGE

Co-location Synergies

TRANSESTERIFICATION

PRESS

CAKE

BIODIESEL

Oil

pressing

CRUDE

GLYCEROL

Washing

WASTE

OIL

VIRGIN

OIL

CRUDE

BIODIESEL

WASHWATER

METHANOL + KOH

Anaerobic

Digestion

BIOGAS

OIL CROPS

ALGAE

Centralized Farm Oil Refinery

Periphyton Bio-Reactors

Biogas

High-Nutrient

Wastewater

Anaerobic

Digestion

Algal Sludge

Algal Cake

Biodiesel

Glycerin

Bioregional

Processor

Clean

Water

Biofertilizer

WATER

SUNLIGHT

Energy

Crops

Biogas

Plant

Biofertilizer

CO2

CO2 WATER

Methane

Green Grass to

Green Gas

Moo-ving to Sustainability

• Biogas

– Environmental compliance

– Carbon credits

• Manure nutrients

– Biofertilizer for bioenergy crops

• Biodiesel

– Fuel and Feed

Photovoltaic panels at Limes Farm, Bourne, UK

Source: Smye Holland Associates Limited, Peterborough, UK. 12/23/2010

http://www.smye-holland.com/SmyeHolland_NewsDetail.aspx?PressRelease=2918

Photovoltaic panels at Red Fire Farm, Granby, MA.

Source: Daily Hampshire Gazette, Northampton, MA. 9/13/2010

http://www.gazettenet.com/2010/09/13/seeds-change

Wind machines on farm.

Source: Farm CPA Today, 7/20/2009

http://www.farmcpatoday.com/2009/07/

Israeli farmers use barn roofs to generate electricity.

Kfar Vitkin, Israel. 11/11/2009

Source: http://www.life.com/image/93252134

Glazed flat-plate collectors for an on-farm milk processor

(Enerworks & Ronnybrook Farms).

Source: Ministry of Agriculture Food & Rural Affairs, Ontario, CA.

http://www.omafra.gov.on.ca/english/engineer/facts/sol_wat.htm

Further Reading …

• Our Ecological Footprint: Reducing Human Impact

on the Earth. Mathis Wackernagel & William Rees

(1995).

• Enriching the Earth: Fritz Haber, Carl Bosch, and

the Transformation of World Food Production.

Vaclav Smil (2000).

• Beyond Oil: The View from Hubbert’s Peak.

Kenneth S. Deffeyes (2006).

• Eating Fossil Fuels: Oil, Food and the Coming

Crisis in Agriculture. Dale Allen Pfeiffer (2008).

Ann C. WilkieSoil and Water Science Department

University of Florida-IFAS

acwilkie@ufl.edu

Midwest Manure Summit

Lambeau Field, Green Bay, Wisconsin

February 16, 2011

Ecological Impacts on Future Farming