Soil Studies 2


Soil pH, moisture, temperature, and the rate at which water percolates into the ground have a direct affect on the plants that are capable of growing in the soil.  The plants growing in a particular area influence the animals that are present in that area and all these factors combined have a direct influence of the biodiversity of the ecosystem.  For example, the current weather conditions are affecting both soil temperature and soil moisture levels. The amount of sun, clouds, precipitation or air temperature on any given day can impact the many different factors that influence the biodiversity of an ecosystem.  A healthy ecosystem with complex interactions between living and nonliving components starts with a healthy foundation...

the soil.


Soil pH

Use the 250mL plastic bottle, Vernier LabQuest, pH sensor, and pH paper in your field box to determine the soil pH of your sample.  Turn on your LabQuest and remove the pH sensor from the box.  Plug in the pH sensor to any channel at the top of the LabQuest.

Unscrew the lid of the plastic bottle.  Measure a heaping teaspoon of soil and pour it into the water inside the bottle.  Vigorously shake the soil/water mixture for a minute or two until the water is cloudy.  Allow the soil particles to settle to the bottom of the bottle (about 5 - 10 minutes) before taking any measurements.  Once the particles have settled:

1.  Tip the bottle gently to one side being careful not to stir up the soil particles that have settled to the bottom.  Insert the pH paper into the liquid and wait about 10 seconds before removing the paper.  Match the color of the pH paper with the proper color on the pH paper bottle.  Record your findings in the "Soil pH using pH paper" blank below.

2.  Insert the pH sensor into the bottle being sure not to touch the soil in the bottom of the bottle with the sensor!  Click the green arrow collect button and collect data for 30 seconds.  On the graph page, click the "Analyze", then "Statistics", then "pH". Look at the results and determine the average (or mean) of your data.  Record your findings in the "Soil pH using sensor" blank below.   

 

Based on the soil pH you measured with the sensor, use the "Soil pH Tolerance for Woodland Trees" chart to name TWO woodland trees that would grow in this soil pH.  Enter them in the spaces provided below.

Soil Temperature

Use the Vernier LabQuest and Temperature sensor in your field box to determine the soil temperature at 1 inch deep and 3 inches deep.

Turn on your LabQuest and plug in the temperature sensor to any channel at the top of the LabQuest.

Insert the temperature sensor into the soil about 1 inch deep.  Click the green arrow collect button and collect data for 30 seconds.  On the graph page, click the "Analyze", then "Statistics", then "Temperature".  Look at the results and determine the average (or mean) of your data.  Record findings in the "Soil Temperature 1" deep".  Repeat entire procedure at 3 inches deep.  Record findings in the "Soil Temperature 3" deep".

 

Soil Moisture

Use the Vernier LabQuest, soil moisture sensor, and trowel in your field box to determine the soil moisture of your sample.  Turn on your LabQuest and plug in the soil moisture sensor to any channel at the top of the LabQuest.  Use the trowel to make a small opening in the ground.  To do this, push the trowel straight down into the ground.  Then move it back and forth to widen the opening.  Pull the trowel out of the ground, move it over slightly, and repeat until the opening is at least 6 inches long and 3 inches deep.  Keep any extra soil nearby - you will need it later!


Once the opening is made, place the connected soil moisture sensor into the opening LENGTHWISE (see photo).  With the sensor in the opening, carefully press the soil around the sensor.  Be sure to cover the entire sensor and GENTLY press the soil down on either side and on top of the sensor!  Click the green arrow collect button and collect data for 30 seconds.  On the graph page, click the "Analyze", then "Statistics", then "Soil Moisture".  Look at the results and determine the average (or mean) of your data and record your findings in the "Soil Moisture" blank below.   

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Percolation Test

Use the plastic yogurt cup and stopwatch in your field box to complete the percolation test.  Percolation or infiltration is the movement of water through the openings (pore space) in soil.  So, a soil percolation test measures how quickly water will soak (percolate/infiltrate) into the soil.  This is important because plants need this water for growth.  If water percolates too slow (puddles on the landscape) or too fast (runs off the landscape causing erosion and other problems) the plants will not get the water they need to survive.


To begin, fill your plastic yogurt cup to the blue line with water from the water jug near the instructor.  Also, make sure your stopwatch is in timing mode "0:00:00" and you know how to use it properly.   Pour the water from your cup into the hole and start the stopwatch immediately.  Watch the water in the hole.  Once all the water in the hole has disappeared immediately stop the stopwatch.  Record the time on the stopwatch in the "Percolation Test" blank below.  Enter the current time on the stopwatch into the blank below.  If it does not finish enter N/A.

Enter your results in mm:ss format.