Unit 1: Impacts of Land Use
In this introductory unit, students will learn about the fundamental role of observation by viewing photographs of both agricultural and non-agricultural (natural) landscapes and making independent observations. They will learn how to relate physiographic features to land use by drawing conclusions about how the physiography of the land affects or is affected by various land use practices. They will then discuss their observations in small groups, organize their thoughts, and explain their conclusions in a classroom oral presentation. Finally, students will consider landscape features in the context of Earth systems and discuss how these systems are impacted by human activity.
Unit 1 supports the following overarching goals of the Growing Concern Module:
Use physiographic and land use data to develop a plan for sustainable soil management in one or more agricultural setting
Predict agricultural challenges that might result from climate change using systems thinking.
By the end of the unit, students will be able to:
- Use objective language to discuss and record the physical features of various landscapes presented in photographs.
- Use their observations to compare and contrast agricultural with non-agricultural landscapes.
- Infer how agricultural practices can impact agricultural landscapes and soil sustainability.
- Explain how Earth's spheres interact with one another in the context of agricultural systems.
This unit directly supports multiple InTeGrate guiding principles, and addresses grand challenges by helping students view soil as a natural resource that is vital to the sustainability of agricultural systems. Students practice the methods of geoscience by making their own observations and considering the differences between these observations and their interpretations. Students are introduced to the interdisciplinary nature of societal problems by recognizing the role of natural and anthropogenic processes in shaping the landscape. Finally, students consider basic interactions among the spheres as an introduction to systems thinking.
Context for Use
This unit is designed to be used in any 50-minute introductory soils/agriculture, geology, or environmental science class as an introduction to geoscientific thinking. It can be conducted in any size class, and can easily be used in different classroom settings without making adjustments. There is no special equipment required and students will not need mastery of other material before its use. Activities are written for in-class use, but the small-group work could be altered to serve as homework (see Teaching Notes and Tips).
Description and Teaching Materials
When you are driving through the countryside or walking through a park, do you watch the rows of crops drift by or do you notice how the trees you are passing relate to the landscape? Your students will learn to view the landscapes around them in a new light after completing this unit. They will spend approximately 15 minutes in small groups observing and describing pictures of both agricultural and non-agricultural landscapes. They will then interpret the relationship of the physiographic features in the photographs to the actual land use. Comparing agricultural land use and its obvious physiographic impacts to non-agricultural land will help them to understand this type of anthropogenic impact on the land. This unit takes approximately 50 minutes and is intended for introductory classes in soils/agriculture, environmental science, or geology.
This unit precedes Unit 2, which explores distinctions in basic soil properties between land use types. It can be completed individually and could also be used to prepare for a quantitative activity such as exploring the influence of Humans as Geomorphic Agents.
This unit is designed to use observations and thought questions to develop observational and critical thinking skills through small group work and classroom discussion.
Begin with the following brief classroom discussion (10 minutes) :
- After reviewing the learning objectives on Slide 2 of the Landscapes PowerPoint™ Landscapes Powerpoint (PowerPoint 2007 (.pptx) 18.4MB Feb2 15), begin with a brief class-wide overview of how to objectively describe and interpret landscapes from photographs. Use Slide 3 (a physiographic satellite image of the United States) and ask students to identify different regions of the country characterized by different landscapes. As they are looking at this image, help them understand what the term "physiographic" means. (Physiography is used here to refer to physical geography, or the physical features of geological landforms. In the small group work, students will be looking at landform shape, attitude, and soil and vegetative cover among other features.)
- Then, for comparison, show the class Slide 4, which shows the actual major physiographic divisions of the conterminous United States. Then ask students "What words would you use to describe the landscape around where you live?" Discuss what words might be useful in describing what they observe in the photos.
- Next, show the students Slides 5 and 6 without specifically telling them that they are observing an agricultural and a natural landscape. Have them practice making objective observations and give them some pointers for the observation exercise (the small group work to follow). Slide 7 depicts the difference between observation and interpretation. This will give them an idea of what is expected of them and will allow them to practice before they begin making their observations.
Small group work
The small group work starts by having students practice their powers of observation, followed by the small groups discussing and interpreting their observations.
Observation (15 minutes): Divide students into small groups of three or four and either give each group a stack of photos of each type of landscape or project Slides 8 and 9 for a few minutes each, switching back and forth several times during the small group work time. If slides are projected, the instructor may want to make one or two sets of the photographs available for close-up viewing. Provide each group with the student instructions and one response table:
- Student Instructions (pdf version) (Acrobat (PDF) 12kB Feb2 15)
Student Instructions (MS Word version) (Microsoft Word 2007 (.docx) 17kB Feb2 15)
- Response Table (pdf version) (Acrobat (PDF) 28kB Feb2 15)
Response Table (MS Word version) (Microsoft Word 2007 (.docx) 18kB Feb2 15)
Remind them to start by simply making observations without making any interpretations of their observations. They should then observe and list the physiographic features of the landscapes they are viewing.
Discussion (15 minutes): The students should then begin discussing their observations in small groups as follows:
- Groups should compare the physiographic similarities and differences between the two landscape/land use types. Each group should use the questions on the Student Instructions sheet to help them interpret the effects of agriculture on the landscape and, to a lesser extent, the effects of weather/climate.
- Each group should record all of their observations and all of their responses to the questions on one Response Sheet.
- Students should then organize their thoughts as a group and summarize their conclusions as a short presentation for the classroom discussion that follows.
(10 minutes) Bring the groups back together and encourage students to use the remaining time to describe their observations and interpretations of how the obvious physiographic impacts of agricultural land use compare to natural land. Follow with a classroom discussion of the impacts of different types of agriculture. Project Slides 8 and 9 during the discussion so that the class can view the photographs as they are being discussed. The Talking Points provided for this exercise include important discussions about soil erosion, sustainable agriculture, and systems thinking, including exploring the potential impacts of climate change on agriculture. Talking points for classroom discussion (pdf version) (Acrobat (PDF) 165kB Oct15 14); Talking points for classroom discussion (MS Word version) (Microsoft Word 2007 (.docx) 19kB Oct15 14)
- The classroom discussion should begin with the instructor checking that the students understand some of the potentially unfamiliar terms described in Section 1 of the Talking Points for Classroom Discussion (which are also shown on Slide 10). Ask students to identify images that they believe best feature soil erosion, runoff/infiltration, organic matter, anthropogenic effects, and ecosystems. Use the definitions provided in Section 1 of the Talking Points for Classroom Discussion.
- Next, ask students to use their observations to reflect aloud on why it's important to care about soil erosion. Use Section 2 of the Talking Points to support their reflections.
- Lastly (Section 3 of the Talking Points), ask them to use the photos to infer examples of what they think are either sustainable or unsustainable agricultural practices. Also ask if they are able to infer the influence of weather or climatic effects on the agricultural landscapes.
- Wrap up by asking them to discuss, as a group, what they think humans will do if our agricultural practices disrupt our food supply.
Wrap-up homework (very short)
Provide the following homework sheet or, if class time allows, complete this activity at the end of the classroom discussion. The purpose of this part of the exercise is to have to students look at the big picture to take what they learned and consider the various connections as Earth's spheres are all interrelated. The activity is provided as Slides 15 through 17 in the Landscapes PowerPoint™ for use in the classroom.
- Unit 1 Wrap-Up Homework (Acrobat (PDF) 1018kB Feb2 15)
Unit 1 Wrap-Up Homework (MS Word version) (Microsoft Word 2007 (.docx) 1.9MB Jul20 15)
Photographs, separated by land use
- Agricultural Landscape Photos (Acrobat (PDF) 493kB Aug11 13)
- Non-Agricultural Landscape Photos (Acrobat (PDF) 697kB Aug26 13)
Student instructions and response table—instructions and leading questions for small groups to use in making observations of the photographs
Teaching Notes and Tips
Instructors can customize the module to focus on landscapes in their area by adding locally representative landscape photographs.
In addition, instructors should consider the following helpful hints while preparing for this unit:
- The Student Instructions should lead most students in making their observations of the photographs, but some may need help in this area because many students have not spent time looking at landscapes in any detail. All students should be reminded to be objective when making their observations.
- Students may also require some guidance when attempting to answer the final question on the response sheet, "What other factors might contribute to the condition of either of these land use types?" This question is intended to encourage them to think about other factors, aside from land use, that affect landscapes. The lack of specific suggestions is intended to encourage students to "think outside the box" about anything that might be a contributing factor. If students need suggestions to get started, questions such as "Do you think rain/snow might contribute significantly to erosion?" or, "What effect do you think the climate might have on erosive forces here?" or questions about altitude, latitude (again, climate), or weather may prompt them to think about other contributing factors.
With the instructor's help, the discussion—fueled by the talking points—should enable the students to begin understanding their observations in the context of the real world.
- Once students understand that when soil erodes, yields suffer, they will begin to see soil as the natural resource it is.
- When students begin to understand the impact of weather/climate and of agriculture on soil, they will be using systems thinking.
- Tell students that by making objective observations and by interpreting what these observations mean, they are using the same methods that scientists use.
Using the small-group work as homework: If class time is limited, students can be assigned to small groups to meet outside of class to do the small group work described above. Alternatively, the work might be done by students independently. The classroom discussion will then bring the groups back together with the instructor present. The wrap-up homework should be done after all of the previous work has been completed.
- Talking points about photos for instructors (pdf version) (Acrobat (PDF) 44kB Sep19 14)
Talking points about photos for instructors (MS Word version) (Microsoft Word 2007 (.docx) 15kB Sep9 14)
- Talking points for classroom discussion (pdf version) (Acrobat (PDF) 165kB Oct15 14)
Talking points for classroom discussion (MS Word version) (Microsoft Word 2007 (.docx) 19kB Oct15 14)
The objective observation skills and students' ability to compare and contrast agricultural with natural landscapes can be assessed by the instructor after collecting the response tables for review. The homework will allow the instructor to assess whether the students have been able to place what they have learned about landscapes, soil, and agriculture into the bigger picture of Earth's systems.
Answer keys are provided here for the Response Table and for the Homework. The keys are to be used not for exact answers to every question, but to give the instructor an idea of what to expect from students.
References and Resources
- Arnold, J. G., K. N. Potter, K. W. King, and P. M. Allen, 2005. Estimation of soil cracking and the effect on surface runoff in a Texas Blackland Prairie watershed, Hydrological Processes, Vol 19, pp. 589–603.
- Govaerts, B., K. D. Sayre, K. Lichter, L. Dendooven, and J. Deckers, 2007. Influence of permanent raised bed planting and residue management on physical and chemical soil quality in rain fed maize/wheat systems, Plant and Soil Magazine, Volume 291, Issue 1-2, pp 39-54
- Riihimaki, C. retrieved 6/13/13, Humans as Geomorphic Agents, Science Education Resource Center, Teaching Geomorphology in the 21st Century, Activity
- United States Department of Agriculture Soil Quality Information Sheet, retrieved 7/30/14, Soil Quality Resource Concerns: Soil Erosion
- United States Department of Agriculture Soil Quality Information Sheet, retrieved 7/30/14, Soil Quality Indicators: Organic Matter