Soils Benchmark Review Packet
SOILS BENCHMARK ASSESSMENT
Student Review Packet
In the space below, answer questions 1 through 3.
1. What is loam?
An agricultural soil that has an optimum combination of different soil particle
sizes. It contains 40%
2. What is soil porosity?
A measure of the volume of pores or spaces per volume soil and of the average
distances between these spaces
3. How does the soil porosity relate to the size of the particles found in that soil?
The larger the particles, the more space between them. The smaller the
particles, the less space.
MISC
Define (look in the wetlands reading):
1. Anoxic:
Without oxygen
2. Hydric:
Filled with water
3. Buttressed:
The base of the tree is widened for support because the soil is very wet.
Why would farmers apply lime to soils? (remember lime = calcium carbonate)
For acidic soil, lime helps raise the pH so that the soil can support plant growth.
List the Macronutrients
1. Nitrogen
2. Phosphorus
3. Potassium
List the Micronutrients:
1. Calcium
2. Magnesium
3. Sulfur
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Soils Benchmark Review Packet
Use the Soil Texture Triangle below to answer Numbers 4 through 6.
4. What would you classify a soil that is composed of 60% sand, 30% silt, and 10% clay?
Sandy loam
5. What would you classify a soil that is composed of 20% sand, 10% silt, and 70% clay?
Clay
6. What would be the particle composition of a soil that is classified as sandy clay?
50% sand, 40% clay and 10% silt
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Soils Benchmark Review Packet
Label the following Soil Profile and use it to answer Numbers 7 through 9.
Organic Layer
Topsoil
Subsoil
Weathered
Bedrock
Bedrock/
Parent Rock
7. Identify the layer(s) of soil in which each soil process occurs.
Subsoil
a. accumulation -
b. decomposition c. leaching -
Organic layer
Topsoil
d. weathering - Weathered bedrock and bedrock
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Soils Benchmark Review Packet
8. Identify the layer of soil in which you would expect to see the following soil colors
a. Dark brown to yellow -
Topsoil
b. Determines the color of the soil -
c. Black, dark brown -
d. Brown, reddish to orange -
Bedrock
Organic layer
Subsoil
9. Where in the soil would you find the highest concentration of plant roots? Why?
Most of the roots would typically be found in the topsoil. The topsoil is the layer
that should have the most plant nutrients that the plant needs to grow and the
composition of the layer should be loose enough for the roots to grow.
10. As you move down in the soil profile does the color darken or lighten? Why?
This is due to leaching. When water moves down the soil layers, it carries minerals
from one layer to another. The soil that loses minerals becomes lighter and the soil
that gains minerals becomes darker.
Weathering
List the methods of chemical and physical (mechanical) weathering
Chemical
Physical
 Oxidation
 Gravity
 Acid rain
 Root action
 Acids from plants
 Thermal expansion
What type of erosion do you think created or changed the following landmarks?
1. Grand Canyon:
Erosion from water
2. Niagara Falls:
Erosion from water
What has the largest impact on the speed of weathering?
Changes in climate
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Soils Benchmark Review Packet
Use the following tables to answer Numbers 10 and 11.
SOIL REQUIREMENT FOR SOME PLANTS
Name of plant
Strawberry
Sweet corn
Deciduous trees
Evergreen trees
Sweet potatoes
Peaches
Spinach
Tomatoes
Watermelons
String beans
Nitrogen
necessary
Med
High
Med
Low
Low
Med
Very High
Med
Med
Low
Phosphorus
necessary
Med
High
Low
Low
Med
Low
Very High
High
Med
Med
Potassium
necessary
Low
High
Low
Low
High
Med
Very High
High
Med
Med
pH requirement
5-6
6-7
5-6
4-5.5
4.8-6.5
6-8
6.4-7
6-7
6-7
6-7.5
SOIL NUTRIENT ANALYSIS RESULTS
Soil Sample
Nitrogen level
A
B
C
D
E
Med
Med
Low
High
Med
Phosphorus
level
Low
High
Low
High
Low
Potassium level
pH level
Med
High
Low
High
Low
7.5
6.5
4.0
7.0
5.0
10. Identify which plant would be best suited for each soil sample?
Sample A -
Peaches
Sample B -
Tomatoes
Sample C -
Evergreen trees
Sample D -
Sweet corn
11. Which nutrient prevents strawberries from growing well in soil sample E?
Sample E would need more phosphorus to support strawberries.
12. Besides testing for nutrients, what else could you look for in the soil to see if it is healthy? Explain
why these are good soil indicators
Insects, worms or other soil organisms. These are good soil indicators because if
they are present it means that the soil is healthy and has a good amount of
nutrients in it.
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Soils Benchmark Review Packet
In the space below, answer Numbers 13 through 20.
13. What is erosion?
The movement of soil from one location to another
14. Name four agents of erosion.
Wind, water, ice, and gravity
15. How do glaciers contribute to erosion?
Glaciers slowly move down the slope they are sitting on, as they move they pick up
soil in the ice and snow. This ends up moving the soil from one location to another.
16. What is deposition?
The process by which weathered materials carried by agents of erosion are dropped
in new places
Explain the two methods used by a construction site to minimize the off-site loss of
sediment.
21. Perimeter Control Various devices (basins and traps, straw bales and silt fences) are used to slow the
velocity of running water and to capture sediment.
22. Temporary Stabilization To control erosion of soil, plants such as trees, shrubs and grass are planted. Also,
mulch can be spread out.
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Soils Benchmark Review Packet
Fill in the chart below with the Agriculture BMP that matches the picture.
Name and description of the Best
Management Practice
Best Management Picture
Contour farming
Description:
1. Follows the hill
Farming with row patterns level
around the hill
Crop rotation
Description:
1. 5 Year sequence for planting
Change the crops grown in a field
year by year
Cover crop
Description:
1. This technique helps fertility
and erosion control
2. Small grain used to uptake
nitrogen and prevent soil erosion
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Soils Benchmark Review Packet
Wetlands
23. Explain why wetlands called “nature’s sponge.”
Wetlands catch runoff of rain water as it drains from the land, soaking it up before it
reaches open water, such as rivers or lakes. This helps absorb any pollutants that are in
the runoff.
24. Which of the following are benefits of wetlands? (Circle all that apply)
A. They help control flooding.
B. They provide habitats for many animals.
C. They filter nutrients.
D. They provide many of the foods we eat.
A, B, C, and D are all benefits of wetlands.
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