Target Grade Level / Age Range:
By the end of this lesson, students will be able to:
- Identify how agriculture uses energy.
- Understand how utilizing energy has increased agriculture productivity
- Identify potential solutions to increasing energy efficiency in agriculture
- Writing surface
- Access to computers and internet for each student
Suggested Companion Resources
- Indirect Energy: that which is used off the farm in order to manufacture farm inputs
- Direct Energy: direct consumption of fuel, gas or electricity
- Energy Conservation: reducing or eliminating usage to save energy
- Energy Efficiency: getting the most productivity from every unit of energy
- Renewable Energy: naturally occurring energy sources that are quickly regenerated and do not pollute the environment
Interest Approach or Motivator
Pose two questions to students. Capture responses on a writing surface.
- How do you think agriculture and energy are related?
- What parts of agriculture are most energy intensive?
Objective 1: Identify how agriculture uses energy
Agriculture can be energy intensive. Gasoline and diesel power vehicles, tractors and generators. Electricity powers lights, irrigation systems, pumps, heating and cooling units, and other automated systems. Natural gas or propane can be burned in hot water heaters or propane dryers.
Have students work in three groups to identify as many places as they can on a farm where energy is used. Give them 3 to 5 minutes to brainstorm. To help direct their thinking the instructor could provide a different prompt question to each group.
- Where in indoor animal production (poultry and swine) systems is energy used?
- Where in outdoor animal production (cattle) systems is energy used?
- Where in plant production systems is energy used?
- Where in the transportation of agriculture commodities is energy used?
- How do people living on a farm use energy in the home?
- Where is energy used in the production of agriculture inputs (fertilizer, feed, etc.)?
Have each group share their brainstorms. Have students capture the following information into their notes.
- Agriculture and Energy are closely linked
- U.S. farm production has become increasingly mechanized and requires timely energy supplies at specific stages of the production cycle.
- Agriculture spends about $30 billion a year on energy, which is 15% of total production costs.
- Unexpected price jumps or energy supply disruptions can easily negatively impact farm revenues.
- With agriculture’s large energy inputs, food prices are directly affected by fuel prices. High Oil Prices = High Food Prices
- Types of Energy Use in Agriculture:
- Direct Energy (~5% of expenses)
- Diesel: tractor field work, irrigation, grain drying
- Gasoline: smaller vehicles and older equipment
- LP & Natural Gas: grain drying, space and water heating
- Electricity: building and equipment operations, grain drying, irrigation
- Indirect Energy (~10% of expenses):
- Commercial nitrogen fertilizer is made from methane in natural gas
- About 5½ gallons of fossil fuels go into fertilizing one acre of soil
- Synthetic pesticides are made from energy-intensive chemical processing
- Energy cost per crop: Of eight major crops, corn and rice have the highest energy-related costs and soybeans have the lowest. (Use chart from Ag Energy curriculum)
- Direct Energy (~5% of expenses)
Examples of energy use:
- Grain Drying: Farmers use a significant amount of energy to dry crops, such as grain, tobacco, and peanuts. Several types of energy can be used for crop drying, including LP gas, electricity, diesel fuel and natural gas. Annual rainfall can have a significant effect on the amount of energy used to dry crops from year to year. For example, above-average rainfall, especially just prior to harvest time, can increase the moisture level of grain. In order to meet quality standards it may require more energy to dry the grain.
- Livestock: Weather can also affect the energy used in livestock facilities and other farm buildings that use various forms of energy for heating, cooling, and air circulation. Natural gas is commonly used to control greenhouse temperatures and dairies rely heavily on electricity to power milking machines and other equipment.
- Irrigation: While many irrigation systems in the U.S. are gravity flow systems that require little or no energy for water distribution, irrigation systems that use pumps to distribute water use energy. Based on the 2003 USDA Farm and Ranch Irrigation Survey, about 43 million acres of U.S. farmland were irrigated with pumps powered by liquid fuels, natural gas and electricity, costing a total of $1.55 billion (USDA NASS 2004). Electricity was the principal power source for these pumps, costing $953 million to irrigate 24.1 million acres at an average cost of $39.50 per acre. Diesel fuel was used to power pumps on about 12 million acres and natural gas was used on about 5 million acres (USDA NASS 2004).
Objective 2: Identify how using energy has increased agriculture productivity
Throughout the 1800s and early 1900s horses were the primary draft animal and used to pull everything from carriages and vehicles to plows. We still use horsepower as a unit of measure to determine power output of engines. What other units do we use to measure power from fuel? Electricity? Natural gas?
Although mechanized agriculture has become more energy intensive, it is more efficient than ever. Productivity has increased 350% since 1970. Ask students where they think this increase has come from.
Answer: Energy efficiency began to improve when farmers began switching from gasoline equipment to more efficient diesel engines and began minimum tillage practices. Since then, more efficient machines and processes have been introduced thanks to advanced technology. Changes in the types of commodities produced have also led to these improvements. The introduction of GMO seed has also been attributed to a reduction of on-farm energy inputs.
Write the following numbers on the board: 22.4, 80, 10, 30. Have students use the numbers to fill in the blanks in the slides as they record the information in their notes.
- Benefits of using energy to increase agriculture production
- Energy use has allowed for fewer humans doing the work. Producers pay less in wages but more for electricity and fuel.
- Energy used by the US food system accounted for 80% of the increase in American energy use between 1997 and 2002.
- Food system energy use increased by 22.4% while total energy use rose by just 3.3%.
- Between 1996 and 2006 farm labor use fell by nearly 30%, while farm equipment use increased by 10%.
- Commercial farms are using larger machinery, greater mechanization, and higher amounts of nitrogen fertilizers made from methane/natural gas.
Iowa farmers spend nearly a billion dollars a year on energy for crop and livestock production.
Objective 3: Identify potential solutions to increasing energy efficiency in agriculture
In the same three student work groups, assign each group one of the categories of increasing energy efficiency in agriculture (sustainable farming practices, energy conservation and efficiency, on-farm renewable energy production). Provide each group with the over view of their subject and the examples. Give each group 5 minutes to become familiar with the ideas and ask questions. Give each group 15 minutes to conduct research on the internet to provide as many examples as possible of their assigned category that are currently being implemented by farmers.
After students have researched, they should come back together. Each group will provide an explanation of their assigned areas and present the examples that they found.
- Sustainable Farming Practices
- Being less affected by volatile energy prices is mostly attained through efficiency measures associated with petroleum driven machines. For example, variable-rate technologies (i.e., precision planting & customized N/P/K application) reduces diesel use by tractors and natural gas used in the production of fertilizers (often manufactured overseas).
- Protection of natural resources vital for farming is a direct effect of less fossil fuel use and its associated pollutants. Clean air, water and soil are essential for productive and sustainable farming.
- Energy Conservation & Efficiency
- Reduced Costs and Increased profits are attained by lower fuel and energy bills, realized by less energy consumption.
- Improved processes & productivity are attained through more reliable and efficient equipment that are generally associated with fine-tuning and upgrading equipment for efficiency. For instance, studies have shown higher worker productivity and safety when dairy barns are lit with brighter high-efficiency lights, this is also an example of i ncreased profits.
- On-Farm Renewable Energy Production
- On-farm energy conservation and efficiency measures could save up to $1 billion a year.
- Farms have great potential to generate renewable energy with their abundant natural resources.
- Solar power
- Wind power
- Biomass fuels
Review the three objectives of the lesson having students provide an explanation to each of these statements.
- Modern farming relies on large, timely energy supplies at specific stages of production to achieve optimum yields.
- Fuel prices greatly affect agricultural inputs and outputs.
- Agriculture affects and is effected by climate change.
- On-farm energy production and efficiency are ways for farmers to maximize profits and protect natural resources.
Essential Files (maps, charts, pictures, or documents)
- The research activity can be expanded to an out-of-class group project. Have students create an audio/visual presentation of their findings and be prepared to share their findings with the class in a 5 to 10 minute presentation.
Iowa Agriculture Literacy Foundation
Agriculture Literacy Outcomes
- Theme 1: Ag & the Environment
- Describe resource and conservation management practices used in agricultural systems (e.g., riparian management, rotational grazing, no till farming, crop and variety selection, wildlife management, timber harvesting techniques)
- Evaluate the potential impacts of climate change on agriculture
- Evaluate the various definitions of “sustainable agriculture,” considering population growth, carbon footprint, environmental systems, land and water resources, and economics
- Theme : STEM
- Describe how agricultural practices have contributed to changes in societies and environments over time
- Identify current and emerging scientific discoveries and technologies and their possible use in agriculture (e.g., biotechnology, bio-chemical, mechanical, etc.)
- Evaluate the benefits and concerns related to the application of technology to agricultural systems (e.g., biotechnology)
Education Content Standards
- HS-LS2-7. Design, evaluate, and refine a solution for reducing the impacts of human activities on the environment and biodiversity.
- HS-ESS3-2. Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios.
- SS.9–12.E.2 Essential Concept and/or Skill: Understand the role of scarcity and economic trade–offs and how economic conditions impact people’s lives.
Common Core Connections
- SL.9–10.1 Initiate and participate effectively in a range of collaborative discussions (one–on–one, in groups, and teacher–led) with diverse partners on grades 9–10 topics, texts, and issues, building on others' ideas and expressing their own clearly and persuasively.
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