Energy Use in Agriculture Issues and Directions

1
Energy Use in Agriculture Issues and Directions

• General Aspects about energy and agriculture
• Specific input issues
• Greenhouse industry as model
• What is happening in Holland and Germany

2
Background Solar Energy

• The foundation of all agriculture rests on the
  unique capability of plants to convert solar
  energy into stored chemical energy.
• Success of agricultural production is measured by
  the amount of solar energy that is captured and
  converted into food per unit of land as a result
  of manipulating plant, land, water and other
  resources

3
Background

• Agriculture success can be enhanced by finding
  ways to augment solar energy using human, animal
  and fossil energy power.

4
Solar Energy

• 14 billion Kilocalories are radiated annually in
  North America/ha
• 1 Kcal 4,186 joules or 4 BTUs 1 quad 1015
  BTUs
• During a 4-month summer growing season nearly 7
  billion kcal of solar energy reach an
  agricultural ha

5
Solar Energy

• An estimated 30 of the total energy reaching the
  earth is harvested by humans as food and forage,
  while an additional 20 is harvested as forest
  products.
• Humans are harvesting for their use approx. half
  of the solar energy reaching the earth.

6
Solar Energy

• This enormous biomass harvest reduces the amount
  of biomass and energy that is essential to
  maintaining natural bio-populations and
  biodiversity.
• Preserving the biodiversity of plants and animals
  is vital to the integrity of the entire human
  environment, including agriculture and diversity.

7
Energy

• For humans to produce and harvest sufficient food
  they must manipulate the natural ecosystem and
  contribute energy with their own hands, animals,
  machines and mechanization, and/or chemicals.
• The managed agro-ecosystem enables the
  established plants to capture solar energy and
  convert into chemical energy (food) suitable for
  humans and/or livestock.

8
Energy

• In many systems, including intensive agriculture
  with grains, greenhouse crops, there is a net
  energy return to human society.

9
Use of Fossil Energy

• Food system utilizes about 19 of the total
  fossil energy burned in US
• Of this 19, 7 for processing and packaging, 5
  for distribution and food preparation by
  consumers.
• If forestry production and utilization are
  included, the total for the food, fiber and
  forestry sector rises about 5, to 24 of
  national fossil energy use.
• This 24 is similar to that consumed by
  automobiles each year in US

10
Rate of return in calories per fossil fuel
invested for major crops
11
Output/input
12
Energy inputs and costs of winter wheat per
hectare
13
Grain and forage inputs per kg of animal product
and fossil energy inputs (kcals) required to
produce 1 kcal of animal protein
14
Improving Energy EfficiencyMaintaining High
Levels of Organic Matter

• Higher organic matter in soil gt5 is directly
  related to the high energy efficiencies. It
  improves water infiltration and thus reduced soil
  erosion from surface run-off, it diversified
  soil-food webs and helps cycle more nitrogen from
  biological sources within the soil.
• 110,000 kg/ha of soil organic matter in an
  organic corn system could sequester 190,000 kg of
  carbon di oxide/ha. This is 67,000 kg more carbon
  di oxide sequestered than in the conventional
  system. This is the amount of carbon dioxide
  emitted by 10 cars that averaged 20 miles/gallon
  and traveled 12,000 miles per year

15
Energy EfficiencyMaintaining Higher Productivity
per unit area

• In greenhouse cultivation Alberta growers have
  achieved some of the best yields in world with
  cucumbers.
• E.g. 280 cucumbers/sq.m, 2.8 million cucs/ha
• Biological controls
• Reduced or eliminated pesticide use
• Carbon dioxide enrichment
• Water and nutrient recycling technologies
• Energy curtains, heat storage systems, boiler
  efficiencies, computerized controls.

16
Greenhouse cultivation as a model

• Excellent data on energy use for benchmarking
• In 2004, Alberta greenhouse industry energy
  expense was around 16 of gross revenue.
• 16,500,000 for natural gas
• 3,000,000 for electricity
• 220,000 for coal and propane
• Average natural gas use 1.95GJ/m2

17
Greenhouse energy model

• Heating supplied by
• Natural gas 82
• Coal 11
• Propane 5
• Wood 2

18
Greenhouses as models Alternate fuels
19
New Directions Biogas-Cogen
20
Closed greenhouse systems 100 kg of
tomatoes/sq.m

• Better CO2 utilization
• Better Temp and RH controls
• Better insect control
• Better space use efficiencies

21
Labor saving devices -automation
22
Recommendations/suggestions for discussions

• Industry consultations for benchmark data on
  energy use/audits
• Automation
• Organic management
• Water and fertilizer recycling.
• Biological controls/reduced pesticide use
• Higher productivity
• Business efficiencies
• Value adding