Download Soil Exploration

Soil Exploration
Purpose: To compare and contrast different kinds of soil. To measure the rate at which water
drains through the soil and to classify different soil samples.
Materials List:
Samples of soil
Glass Funnel
Graduated cylinder
Clock
dissecting microscope
paper towels
beaker with graduations
filter paper
Procedure:
1. Examine each of the three soil samples using your unaided vision and the dissecting
microscope. Sketch a drawing of each type of soil in your data book using the microscope view
and describe it in detail using the appropriate vocabulary.
2. Moisten a small amount of soil and note whether the moist soil feels grainy or sticky. Note
how well the soil molds (friability). Record this information.
3. Fold a piece of filter paper and place it into the glass funnel. Place 30 grams of soil onto the
filter paper and carefully place the funnel into the beaker as demonstrated by the teacher.
4. Measure 50 ml of water into the graduated cylinder.
5. Gently pour the water from the graduated cylinder over the soil in the funnel. Record the
amount of time it takes for the first drop of water to come through the hole in the bottom of the
funnel. Record the volume of water collected in the beaker after 2 minutes and after five
minutes.
6. Repeat for each different soil sample. Record your data in the table.
Data:
Soil Sample
Feel when moistened
Ease of molding
Time for first drop
Water volume after 2 minutes
Water volume after 5 minutes
1
2
3
Results/Calculations:
Diagram and color your soil samples using the dissecting and compound microscopes. Classify
the samples using the soil triangle.
Questions:
1. Which type of soil drained the fastest? Which drained the slowest? What factors in the soil
do you think resulted in the speed of percolation?
2. Which types of soils contained organic material? How do you know? How would that affect
the number and type of organisms that live in and around the soil?
3. Which of the soil samples would be best for your garden? Explain your answer.
4. Which of the soil samples had the greatest friability? What factors contribute to this
characteristic?
5. Explain why a balanced mixture of sand, silt, and clay results in the best suited soil for
growing plants.
Discussion of Error:
List three possible errors that may have occurred while you were testing.
Conclusion:
Summarize how the different soils are constructed including a description of the size of the
particles included in each sample. Explain where your soil samples belong in the soil triangle and
why.