The purpose of this resource is to understand that variations in landscape can affect soil properties. Students investigate variations in the soils around their school to discover that soil properties like moisture and temperature exhibit considerable variability across a single landscape. They also identify factors such as slope, shade, plants, compaction, which affect the appearance of soils and their ability to hold moisture. Educational levels: Primary elementary, Intermediate elementary, Middle school, High school

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

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Digital Library for Earth System Education

GLOBE® 2005  Digging Around Learning Activity - 1 Soil
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Introduction
Protocols
Learning A
ctivities
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?A Field View of Soil - 
Digging Around 
Purpose
To understand that variations in the landscape 
can affect soil properties 
Overview
Students investigate variations in the soils 
around their school to discover that soil 
properties like moisture, temperature, color, and 
texture exhibit considerable variability across a 
single landscape. They also identify factors such 
as slope, shade, plants, and compaction, which 
affect the appearance of soils and their ability 
to hold moisture.
Student Outcomes
Students will be able to characterize soils.
Students will be able to relate the five soil 
forming factors to soil properties.
Science Concepts
Earth materials are solid rocks, soil, water, 
biota, and the gases of the atmosphere.
Soils have properties of color, texture, 
structure, consistence, density, pH, 
fertility; they support the growth of 
many types of plants.
The surface of Earth changes.     
Soils are often found in layers, with each 
having a different chemical composition 
and texture.
Soils consist of minerals (less than 2 mm), 
organic material, air and water.
Water circulates through soil  
 changing the properties of both the   
 soil and the water.
Scientific Inquiry Abilities
Identify answerable questions.     
Design and conduct an investigation.     
Use appropriate tools and techniques 
including mathematics to gather, 
analyze, and interpret data.
Develop descriptions and explanations, 
predictions and models using evidence.
Communicate procedures 
  and explanations.     
Time
Two class periods: the first for the field trip; 
the second to discuss findings and causal 
connections
Level
All 
Materials and Tools
Small shovel or trowel
GLOBE Science Notebooks
Prerequisites
None
Background
Factors Affecting Soil Properties 
The soil is unique for every place on Earth. What 
makes each soil unique is the way the five soil 
forming factors work together at any particular 
place. These five soil forming factors are 1. 
parent materials from which the soil formed, 2. 
the position on the landscape where the soil is 
found (or the topography of the site), 3. the types 
of plants and animals that live in the soil, 4. the 
climate for the area where the soil formed, and 5. 
the amount of time that the other 4 factors have 
been interacting. As you look around your site, 
notice whether the effects of the five soil-forming 
factors are different on one part of the site versus 
another.
Some properties that you may notice that 
change from one soil to the other are:
• the color
• the type and amount of vegetation on the 
soil surface
• the amount of roots in the soil surface
• the shape of the soil particles when you 
look at them (called the soil structure)
GLOBE® 2005  Digging Around Learning Activity - 2 Soil
• the way the soil feels (called the soil 
texture)
• the amount and size of rocks in the soil
• the number of worms or other animals in 
the soil
• how warm or cool, wet or dry the soil 
feels. (Wet soil will be sticky and clump 
together, moist soil will feel wet and cool, 
and dry soil will feel like it has no water in 
it.)
Factors Affecting Soil Moisture
Because each soil is unique, each soil will also 
hold a certain amount of water. The amount of 
water held in the soil may depend on many things. 
Among these are the speed at which precipitation 
(rain, snow, sleet, etc.) enters (infiltrates) the soil 
or runs off, the temperature, and the plants. If soil 
is tightly compacted, as on a well-trodden path, 
the water will not be able to enter the ground as 
easily as in less traveled areas. Nature may increase 
runoff in some areas. For example, in dry climates, 
“desert pavement” (small rocks laid tightly across 
the sand like a tile floor) may increase the amount 
of runoff.
Wind and water may help to form crusts on 
some soils that prevent the infiltration of water. 
Slope also increases the speed at which water 
runs off the land. Rain will quickly disappear on 
a steep slope, but collect in puddles on the flat 
ground. The roots of plants help to break up the 
soil, creating a porous medium in which water 
can pass. Sandy soils usually let water in faster 
than clay-rich soils.
You might think that there is little variation 
between soil temperatures on your site. 
However, there may be quite a bit of difference 
from one place to another. Shade causes cooler 
temperatures. Shade is not found just under 
trees. It may be cooler in the shade under a rock 
or on the side of a rock away from the sunlight. 
The soil may be drier in warm places, and wetter 
in cool, shady places.
Plants may also affect soil moisture. They may 
provide shade. They also use water.
What To Do and How To Do It
Begin by Asking: 
1.  In your part of the world, which side of a 
slope gets the most sunlight - the north or 
the south?
2.  If you were going to hunt for fishing 
worms (or other soil dwelling 
invertebrates), where would you look? 
Why would you look there? Remember, 
animals need water, air and nutrients, 
which are found in various soils. In 
compacted soils, it is more difficult for 
animals to survive.
3. Do more types of plants seem to grow on 
slopes or in valleys? Why?
At the Study Site
1.  Divide the class into groups of 3 to 5 
students. Each group should have a small 
shovel or trowel, and their GLOBE Science 
Notebooks.
2.  Have groups look for differences in soil 
properties at different places in the site 
by digging up a small amount of soil, 
looking at it, and feeling it. Have them 
record what they find in their GLOBE 
Science Notebooks. 
Ask them to note types of plants, presence 
of rocks, roots, and soil animals (such as 
earthworms), how hard or easy it is to dig, 
distances to items on the landscape or other 
things they notice. See the box, the Five Soil-
Forming Factors (after Student Assessment 
below), for guiding questions. Have students 
list the areas they investigated from the wettest 
to the driest. Note how the moisture content is 
affected by the location, the type of plant cover, 
the position, or other things at the site.
Extensions
1.  Have students make a sketch map of soil 
characteristics on their site. 
2.  Have students “landscape” their site. If 
this site was going to become someone’s 
yard, where would you plant things?
GLOBE® 2005  Digging Around Learning Activity - 3 Soil
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Introduction
Protocols
Learning A
ctivities
The Five Soil-Forming Factors 
Climate: Is one part of the site more 
shaded or sunnier, cooler or warmer, 
drier or wetter? How would the 
temperature and moisture be different 
in a sandy soil than in a clayey soil? 
How would this affect the way plants 
grow?
Topography: Are there different slopes on 
different parts of the site? Where is it flat 
on the site? Are there areas that rise up or 
slope down? What are the different types 
of positions on the landscape (high spots, 
middle of the slope, low areas)? Where 
are the highest places; the lowest?
Plants and animals: How do the types of 
vegetation change on the site? Can you 
see evidence of animal life? What kinds 
of insects are present? How is the site 
used by humans (such as: is it a park, a 
field, a lawn, a forest, a plantation, an 
urban area)?
Parent material: From what kind of 
material was your site formed? Do you 
see rocks at the surface that can give 
you an indication? Are these rocks near 
a stream so that they may have been 
deposited by water? Could they have 
been deposited by wind (such as a sand 
dune), or by gravity down a hill, or by a 
glacier, or by a volcano? (You may need 
to do some research to determine the 
geology of your area).
Time: How long has this site been 
undisturbed? Is there a lot of organic 
material on the soil surface? Are there 
grasses, trees, crops, or other plants 
that have been growing for a long time 
without being disturbed? Has there been 
recent building or construction? If it is a 
field, has it been recently plowed? Have 
trees been removed from the site? Has 
there been a recent flood or other natural 
disturbance that may have affected the 
formation of the soil?
Student Assessment
Ask Students:
1.  In which parts of the site would you 
expect soils to be most alike? Consider 
regions with similar soil forming factors.
2.  Where would you locate the soil that is 
the most typical for your area? Look for 
large areas within your site which have 
common characteristics. 
3.  What things on the landscape affect soil-
moisture?
4.  What things should you consider when 
choosing your soil-moisture site in your 
area?


A Field View of Soil - Digging Around

http://www.globe.gov/tctg/fieldview.pdf?sectionId=105

A Field View of Soil - Digging Around

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