Lesson How Should Our Gardens Grow?

Learning Objectives

After this lesson, the student should be able to:

• Understand and identify the different ways that land is used by humans.
• Discuss the environmental effects of different land cover/land use decisions.
• Describe different types of engineers involved in community planning.
• Write an essay on land use from the viewpoint of a planning engineer.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Introduction/Motivation

Have you ever thought about how you use your space? Look at where you are sitting right now. Do you have lots of clutter (are you a polluter?) or are you well organized? Do you have special containers to put paper, pens and other items in to help you maximize your space? What are ways you could improve your use of space? Should you make a plan?

Community planning engineers frequently think about similar questions but on a much larger scale. In order to reduce pollution, engineers decide where the best areas are for landfills, farms, commercial and industrial businesses, residential homes and many more necessities.

Before houses, malls and businesses are built in a community, land impact studies must be performed to determine what effect the construction will have on the environment. Can you think of some ways that buildings could affect the environment? Students can expand on this idea by conducting the associated activity This Land Is Your Land, This Land Is My Land.

The construction of roads, dams, canals, bridges and tunnels can affect the environment over a very wide area. These engineering projects can destroy natural habitats in many ways (including flooding), and cause air pollution (more roads bring more cars, which brings more pollution). Sometimes the local area has to be dynamited to make room for the construction project and that reduces places for the wildlife and plants to live or find food. One job of engineers is to develop a project plan that has the least harmful effects to the environment.

Many types of engineers are involved in designing, creating and maintaining communities and landscapes. Architectural engineers work alongside architects and focus on safety, cost and construction methods used to design a structure. For example, as the U.S. population grows, architectural engineers are investigating new ways to build on land where there is only sand and sagebrush (the Southwestern area of the United States, for example). Civil engineers deal with buildings, bridges, dams, roads and other structures. They plan, design and supervise the construction of facilities such as high-rise buildings, airports, water treatment centers and sanitation plants. Their work may also involve surveying and mapping. Transportation engineers design streets, highways and other transit systems that allow people and goods to move safely and efficiently. For example, before constructing a new sports stadium, city officials rely on transportation engineers to plan streets and traffic control like stoplights, stop signs and roundabouts that will prevent major tie-ups after the game.

Lesson Background and Concepts for Teachers

Types of Land Use

Farming

People began to farm plants and animals about 9-10,000 years ago. Today, there are generally two types of farming: crops and livestock.

The most important food crops are cereals (wheat, corn and rice), of which half of the world's food is produced. In the 2018/2019 seasons, the U.S. produced about 53 million tons of wheat. This was about 7% of the world total. How much wheat was produced on Earth in the 2018/2019 seasons? (Answer: 765 million tons!)

Farmers add fertilizers to the soil and treat crops with pesticides and herbicides in order to keep fields productive. These chemicals can keep nutrients in the soil and keep pests to a minimum. While these treatments help farms to produce more food, the chemicals can harm the environment. The nitrate and phosphate fertilizers can run off the land and into the water, or go directly through the soil into the water table, causing water pollution. Sadly, pesticides do not just kill bothersome pests, they can also kill local wildlife. Organic farming techniques generally do not use chemicals; organic farmers often rely on natural fertilizers and pest control.

Over 60% of all cereal production in the U.S. is used as animal feed! Ten calories of grain is needed to produce one calorie of beef (cattle are inefficient meat producers). Overgrazing of animals, especially cattle, can cause desertification, which turns natural grasslands into dry, desert lands.

This is currently happening in Sahel, a region of Africa just south of the Sahara Desert. Traditionally, shepherds and their animals moved from one place to another, following the rains just as wild herds are accustomed to doing. In this way, the shepherds let the land "rest" and recover. When people began to settle in towns and villages, the government paid for wells to be dug so there would be water available year-round. Now, however, the land never fully rests. Near the wells, cattle eat the vegetation and trample it. Gradually, the vegetation is destroyed and the underlying soil becomes eroded. What is left is a desert.

Desertification has happened in the U.S. also. When the Midwest had a few dry years in the 1930s, tremendous amounts of soil blew away, creating what is known as the Dust Bowl.

In 1840, Justus von Liebig published a book, Organic Chemistry and Its Application to Agriculture and Physiology, which discussed some ideas quite revolutionary for its time (although quite commonplace today). Mr. von Liebig found that each plant requires certain kinds and quantities of nutrients to survive. He said that the plant will fail if a nutrient is absent and that the plant's growth will be negligible if the nutrient is present in only minimal amounts (this came to be known as the Law of the Minimum). Later research, however, showed that too much of a substance can also be harmful. In 1913, V.E. Shelford expanded von Liebig's ideas to describe the Law of Tolerance, which states that organisms can survive only within their range of tolerance for a particular environmental factor. They fail to reproduce or grow outside this range and have an optimum place within the range where they thrive. Agricultural engineers often use and apply this law when trying to determine the best farming practices for a particular climate and crop/livestock and when creating new fertilizers or herbicides/pesticides.

Forestry

Farming has expanded so much on Earth (to provide food for the expanding population) that most of Earth's forests have been cut down to provide space for farming (as well as for things like paper, fuel and furniture). Slash and burn techniques are often used to clear the land (in which land is burned and a method for clearing out trees, grasses and bushes). Every year, approximately 40 million acres of rainforest are being destroyed. Each person is indirectly responsible for the cutting down of 6-7 trees in order to supply the paper products they use during a year.

Forest destruction also has an effect on the atmosphere because there are fewer trees to recycle the world's carbon dioxide into oxygen. Thus, the carbon dioxide levels in the atmosphere are rising.

Mining

Humans began to perform large-scale mining about 5,000 years ago. Mining provides us with the natural resources (ore and minerals) that factories and skilled workers process into other useful products.

Most iron ore and coal come from pits at the surface of the Earth (open-pit or opencast mining). This causes a permanent scar on the surface environment and often leaves great amounts of dust. The explosives used in blasting apart rock often disrupt other wildlife. Other materials (like nickel, lead, zinc, and the much-harder-to-reach coal) are mined underground. This leaves spoil heaps (artificial hills made of mud and rocks).

Drilling for natural gas and oil often causes the greatest damage to the environment because of the heavy equipment required to establish the field and because of the pipelines that must be used to transport the gas and oil from distant drilling sites.

Recreation

Human recreation has a significant impact on our environment. We use natural environments like lakes, mountains and beaches for entertainment. We also use engineered environments like sports arenas, recreation centers and swimming pools. Many types of engineers (environmental, civil and transportation) work to contain and minimize the impact that our activities have on natural and engineered environments.

Wildlife Conservation

President Woodrow Wilson signed the National Park service Act in August 1916: "To conserve the scenery and the natural and historic objects and the wildlife therein and to provide for the enjoyment of the same...unimpaired for the enjoyment of future generations."

A National Park is a region of land in which development for settlement, industry and mining is banned, and in which wildlife is strictly protected. National Parks are dedicated to the upkeep and preservation of outstanding national features and wildlife and the provision of facilities for recreation. Their greatest concentration is in the western states.

Associated Activities

• This Land Is Your Land, This Land Is My Land - Students will review and evaluate the ways land is covered and used in their local community. They will also consider the environmental effects of the different types of land use.

Lesson Closure

Read "The Boy Who Loved to Swim" by Jean Craighead George (found in Durell, Ann, Craighead George, Jean, and Paterson, Katherine. The Big Book For Our Planet, New York: Dutton Children's Books, 1993). Discuss what land use changes the boy implemented. What impact did the dam have on the environment? Discuss how the boy's opinion about needing a swimming area changed throughout the story. Make comparisons to your own community – are there projects that were done that were later revised or replaced because of their environmental impact?

Vocabulary/Definitions

cereal: Any grain-producing plant that is cultivated for food (wheat, rice, corn, barley, oats, rye, sorghum, etc.).

desertification: Turning dry grassland into a desert. This can happen because of natural climate changes and/or livestock overgrazing.

land cover: Vegetation and other natural features on the Earth's surface.

land use: The human activities associated with land cover (recreation, housing).

law of the minimum: The idea that a plant requires certain kinds and quantities of nutrients to survive. The plant will fail if a nutrient is absent and the plant growth will be negligible if the nutrient is present in only minimal amounts.

law of tolerance: Organisms can survive only within their range of tolerance for a particular environmental factor. They fail to reproduce or grow outside this range and have an optimum place within the range where they thrive.

slash-and-burn: A technique which first, trees are cut down (for lumber or just burned) and the stumps removed. The ash fertilizes the soil, but the land can be used for farming only about once every 30 years. After a few years, the land becomes exhausted and the farmer moves on to clear another area of forest. Sadly, the land left behind suffers from erosion and all the topsoil washes away.

Assessment

Pre-Lesson Assessment

Discussion Questions: Solicit, integrate and summarize student responses.

• Have you ever thought about how you use your space? Look at where you are sitting right now.
• Do you have a lot of clutter (are you a polluter?) or are you well organized?
• Do you have special containers to put paper, pens and other items in to help you maximize your space?
• What are ways you could improve your use of space should you decide to make a plan?

Post Introduction Assessment

Discussion Questions: Ask students to discuss what they like and dislike about where they live, where the school is, and about the layout of the community in general.

Brainstorming: In small groups, have the students engage in open discussion. Remind students that in brainstorming, no idea or suggestion is "silly." All ideas should be respectfully heard. Encourage wild ideas and discourage criticism of ideas. Ask the students: What changes, if any, would they make to the land use in their community? (Note: Students will come up with a lot of different ideas here, but try to keep the discussion focused on the general land use within the community.)

Lesson Summary Assessment

Mapwork: Ask groups of students to study a map of your local area.

• Ask them to describe the types of land use described on the map.
• Ask them to describe other ways that land is used in your area (or other places) that are not included on the map.
• What kinds of effects does each of these uses have on the environment? (Note: See Lesson Background & Concepts for Teachers for some ideas.)
• Ask students to think about what the area looked like about 100 years ago. (Note: It is a great idea to share a map or photos from this time period if you have access to them.)
• Ask them to describe what effect they think the changes during the last 100 years have had on the environment.

Homework

Predictions: Ask students to imagine that they are community-planning engineers. Their job is to make predictions about what they think their community will be like 100 years from now. What do they think it will look like?

• Drawing: Have them draw pictures of their ideas from above.
• Essay: Ask them to describe, in writing, what effect they think these changes will have on the environment (for better or worse).
• Collect essays and discuss during the next class period.

Lesson Extension Activities

Have students create environmentally friendly cities using SimCity® software.

Try out one of the land use simulations at:

• National Park Services Game – https://www.nps.gov/piro/learn/education/landusegame.htm
• USDA Forest Service's "Land Simulation Game" in the "Investigating Your Environment" Curriculum - https://www.fs.usda.gov/detailfull/conservationeducation/materials/national-curriculums/?cid=STELPRDB5107459&width=full

Explore the topic of "Sustainable Living" in more depth. You can find more information at www.interfaceglobal.com

Invite a city planner in to discuss the future development of your community. Ask him/her to discuss how the city plans have evolved over time. (It would be great if they had historical and modern city planning documents to bring along.)

Use aerial photographs instead of maps to explore land use in your community. You can often purchase these from Regional Planning Commission offices. Also check with your county Land Conservation District office. See dnr.wi.gov/education for an activity related to the ones for this lesson, but using aerial photographs.

Have student complete the "To Ski or Not To Ski" simulation from Hand-On Minds-On Science – Environmental Issues (Intermediate), by Pauline Chandler, Teacher Created Materials, Inc., California, 1994 (ISBN 1-55734-638-0).

References

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed under a grant from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education and National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.