Soil Recipes

Activity 1

Purpose:
1. To identify components of soil and how those components determine soil function.
2. To explain how different soil types determine ecosystem characteristics.

3. To predict how soil affects water filtration (percolation).

Materials:
small garden trowel, hand lens, small plastic sandwich bags, beakers with stirring rods or clear plastic jars with lids, pan balance scales, water, 100ml graduated cylinder, graph paper, small metric ruler

Procedure:
1. Determine 5 soil collection sites where you may obtain characteristically different soil samples. Place them in the plastic bags and label as to site.
2. Examine soil samples. For each sample, create a report that answers the following fundamental questions.

a) Where is the soil site?

b) What plants were growing on this site?

c) Was the area level or sloped?

d) Describe the soil using physical properties. ie. color, texture, odor..

e) Describe the size of the particles in each sample. Measure where applicable using the metric ruler.

3. Measure 100ml of dry soil from each sample into each beaker or jar using the graduated cylinder.

4 . Record weight of soil and beaker in a table similar to the one below.

5. Slowly pour water into the beaker until it reaches the top edge of the soil.

6. Weigh each container again and fill the remaining spaces in the table.

WEIGHT OF SOIL + BEAKER
(A) WEIGHT OF SOIL, BEAKER, AND WATER
(B) WEIGHT OF WATER
(B - A = C) VOLUME OF AIR IN SAMPLE
(1gm water displaces 1ml air)

_ _ _ _

7. Continue to add water until the level is 5cm above the soil.

8. Shake or stir the sample vigorously.

9. Allow samples to settle completely (app. 2hr.)

10. Record observations about layers.

Image of two soil samples filled with water 5cm above soil

Think about this:
1. How important are air spaces between soil particles?

2. Why does vegetation vary with soil variation?

3. Which soil allows water to drain more efficiently?

Extension:

1. Graph soil profile results by comparing layers in each sample. (Ratios of sand to silt or clay in each sample.)

2. Obtain a copy of your county’s soil survey or a map of aerial photographs marked for different types of soil. Compare types of soil with what is evident in each area. Are there roads, highways, farmland, ponds, etc.?

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