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Rain Gardens Part 2 - Soil Comparisons in Preparation for Creating a Rain Garden

Keywords: rain garden, soil, clay, sand, silt, texture, absorption, drainage; Grade Level: K-5 – activities and vocabulary can be adapted according to age level; Time Required: Two one-hour sessions; Setting: Outside the school and in the classroom

Subjects:  Science, Math, Language Arts

Topics:  Soil Conservation, Environmental Education

Goals: 

Students will investigate the differences between three to five types of soil, will understand how particle size affects water movement and use, will explain how soil use can be improved through use of rain gardens, will describe community benefits of rain gardens.

Materials Needed: 

journals, pencils, clipboards, sandwich bags that zip, old spoons or spades, paper plates, hand lenses, toothpicks, paper towels, soap, water, jars with lids, teacher samples of clay, sand, silt, and rich forest soils, student page 301 “Soil Investigation” from Project Learning Tree Activity Guide, 4-5 flowerpots with drainage holes.

State Standards Addressed:
Environment and Ecology: 4.1.3.D, 4.4.4.C, 4.4.3.E, 4.4.4.E, 4.4.5.E, 4.5.4.E, 4.5.3.F, 4.5.4.F, 4.5.5.F

Teaching Model: hands on, small group, investigation, data collection, classification, comparison, discussion, analyzing

Methods:

First Session - Review previous lesson “Rain Gardens Part 1 - How Rain Gardens Preserve and Improve Our Water.” Explain how today they will be studying soil and making comparisons in preparation for creating a rain garden. Show them the “Soil Investigation” sheet where they will be completing questions one and two only so they will be aware of the environment where they dig their soil. Divide students into teams, give them digging spoons or spades and a zipped plastic bag marked with an area where they are to dig up about ½ cup of soil.  Be sure to choose areas where there are various soil types, including an area where a school rain garden might be located.  If there are not different soils near the school, bring in different types including sand, silt, clay and wet soil. Return to the classroom and have student teams dump their soil onto paper plates to be analyzed.  Have them use toothpicks and hand lenses (washing when necessary!)  They should complete the first two questions on their worksheets as teams and describe the environment where they got their soil and use their senses to describe the soil’s color, smell, size of particles and texture.  Use this key for color: Black = rich soil, Brown = average soil, Red = clay soil with iron, Yellow = clay soil with few nutrients, Light brown/gritty= sandy soil. (Smith, Sanford S., James C. Finley and Robert Hansen. 1998. Treetop 4-H Forest Resources Guide p. 19. College of Agricultural Sciences Cooperative Extension, Penn State University) Have students touch each other’s soil and make comparisons. Add a few drops of water to each and compare. Sand should feel gritty with visible grains and not remain in a ball when squeezed. Silt should feel smooth and form a short worm that breaks apart when rolled.  Clay should feel sticky and form a long worm when rolled. ( from Beneath Your Feet, The Western PA Conservancy http://www.paconserve.org/144/beneath-your-feet ).  Then seal the soil back in plastic bags until the following session.

Second Session – Early in the day review the previous day’s activities.  Then students make a prediction about what will happen to their soil if they put it in a jar, fill it with water and shake it.  Have them draw their prediction on the top half of the back of their worksheet. Let the jars alone for a few hours, students then observe the contents, make comparisons and draw the results on the bottom half of their worksheets. They should be able to see layers in the jars where larger pieces sink to the bottom. Heavier bits of stone sink first, then pieces of sand, silt and clay followed by lighter organic material such as leaves, stems, bark.  Some may be partially submerged or even float.  Then demonstrate how soil texture affects drainage. Fill flowerpots each with different types of soils including sand, gravel, silt and clay. Next pour water one-at-a-time into them and have students count or watch the time to see how long it takes until water leaks.  Discuss which type of soil would be best for plants to grow in a rain garden.  According to raingardens.org, a mix is the best: 50-60% sand, 20-30% topsoil and 20-30% compost. http://www.raingardens.org/Evaluate_the_Soil.php.  Brainstorm benefits of rain gardens to the school and public community as well as to animals.

Evaluation: 

Assessment will be teacher observation during activities, journal writings and drawings, class participation, completion of page 301 “Soil Investigation” from Project Learning Tree Activity Guide and writing a conclusion about the experiment with flowerpots. 

Literature/Sources

Beneath Your Feet. The Western Pennsylvania Conservancy. http://www.paconserve.org/144/beneath-your-feet

Federici, Tony and Bill Young. Rain Gardens: An Introduction by the Native Plant Society of New Jersey, article in Branching Out. NJ Dept of Environmental Protection, Oxford, New Jersey. http://www.state.nj.us/dep//seeds/bo/bofall05.pdf

Project Learning Tree Environmental Education Activity Guide for Pre K-8  (2009).  American Forest Foundation Washington, D.C.

Smith, Sanford S., James C. Finley and Robert Hansen. 1998. Treetop 4-H Forest Resources Guide p. 19. College of Agricultural Sciences Cooperative Extension, Penn State University.

Three Rivers Rain Garden Alliance.   http://raingardenalliance.org  

Author

Connie Horne, State College Area School District Guest Teacher K-5