AP Environmental Science
DoDEA Virtual High School
The Nitrogen Cycle: Virtual Farm
Name of Student:
Date:
Directions: Go to the site for the Virtual Farm.
http://www.sites.ext.vt.edu/resources/4h/nitrogencycle/nitrogencycle.swf
Part A: Watch the slide show, visit the “farm” and answer the following questions.
1. What percentage of the atmospheric air is comprised of nitrogen?
2. Most plants and animals are able to get their nitrogen directly from the air. True or
False?
3. The movement of unused nitrates to deeper levels or horizons of soil by rainwater is
called
4. Legumes such as soybeans and clover are important because they take atmospheric
nitrogen and make it available in organic matter in the soil. This process is known as
.
5. Animals secrete nitrogen in their
and
.
6. Bacteria convert ammonium (NH4) to nitrate (NO3) in a process called
.
7. Nitrogen is important to living things because it is used to make amino acids which
combine to form
.
8. 90% of the world’s nitrogen is located in the
atoms (N2) called
.
and is comprised of two nitrogen
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AP Environmental Science
DoDEA Virtual High School
9. Plants get their nitrogen from the soil through their
their nitrogen by consuming plants or other animals.
. Animals must ingest (eat)
10. On a farm, not all nitrogen is recycled back to the soil. Some leaves the farm when
the animals or crops are sold. Nitrogen also leaches into lower soil horizons or is
returned to the atmosphere. How do farmers replace this lost nitrogen?
11. When too much nitrogen is added to a field, some of it washes away with the rain as
runoff. This finds its way into ponds, lakes and streams. What effect does this have on
the aquatic plants AND fish in those waters?
Part II: Quiz Questions- Using the information below, answer the following questions.
1. Using the bar chart below, determine how many pounds of nitrogen is in the manure
produced by these two steers during their time in the feedlot.
2.. Not all the nitrogen in the manure is available to help the corn crop. How much
nitrogen in the manure is lost or unavailable?
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AP Environmental Science
DoDEA Virtual High School
3. The Soil Testing Laboratory at Virginia Tech tells us that we need 180 pounds of
nitrogen to grow a good crop. We know that 80 pounds of nitrogen is available to the
corn crop from the manure. There is also some nitrogen available from last year’s crop
residue. From the table below, determine how many pounds of nitrogen fertilizer is
needed.
4. Some of the corn crop is not harvested and remains in the field as crop residue. We
used 180 pounds of nitrogen to grow my corn crop, but 40 pounds of nitrogen was left in
the field as crop residue. How much nitrogen is in the corn we harvest?
5. The cattle gain nitrogen in their bodies as they grow. All of this nitrogen comes from
the feed that they eat. How much nitrogen is gained by the two steers?
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AP Environmental Science
DoDEA Virtual High School
6. The steers need nitrogen from feed to grow. Some of that nitrogen stays in their
bodies and some is lost in the manure. If the corn does not have enough nitrogen for the
steer’s needs, we must purchase nitrogen to make up the difference. Use the calculations
below to determine how much nitrogen needs to be purchased.
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