Students will develop an understanding of agricultural
technology and biotechnologies.
D. Most agricultural waste can be recycled.
E. Many processes used in agriculture require different procedures,
products, or systems.
Objective:
Students will understand the process of crop rotation
and the technology of farming.
Materials: Paper, pencil, access to a BrickLab
Preparation:
IC
Be familiar with brick elements and terminology.
Photocopy the handout provided on page 84.
Background:
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About 14,000 years ago, the Agricultural Revolution
transformed society by allowing humans for the first time to produce
more food than they needed. The development of a variety of
agricultural tools and practices, such as the plow
and irrigation, improved productivity and made it
possible for fewer people to feed all of a society,
thereby freeing up some of the society for other tasks.
Further advances in agricultural technology since
that time have continued the pattern, so that now
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only about one out of a hundred people working on a farm is enough to
provide food for the population of the United States.
One method that allowed for greater food and crop
production was crop rotation. Crop rotation is the
method of growing crops so that no two crops grow in the
same place two seasons in a row. By planting different crops each season,
the soil isn’t overworked, and there isn’t a large build up of pests or chemicals. This allows for higher yields. Crop rotation is mentioned in ancient
Roman literature and is also referred to by cultures in Africa and Asia.
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C. Artificial ecosystems are human-made environments that are
designed to function as a unit and are comprised of humans,
plants, and animals.
#8
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ITEA Standard #15 Agricultural Technology
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Teacher Guide
CROP ROTATION
Soil quality depends a lot on the amount of nitrogen that is in the soil.
Soils with a high level of nitrogen tend to produce a higher crop yield.
Soils with low nitrogen have crops that struggle and produce less. For
the purpose of this lesson, chemical fertilizers will not be used; however,
it should be noted that chemical fertilizers are a very important technology and greatly help increase crop yields.
For the students’ experiment, soil will receive a rating level of high, medium, or low. High soils have 75 nitrogen units, Medium have 35 nitrogen
units and Low have 15 nitrogen units. For the classroom, the heavy nitrogen users bring in more money at harvesting time. If a field has less than
the required amount of nitrogen the crop will fail. Some crops attract nitrogen-fixing bacteria that increase the amount of nitrogen in the soil.
Students will be assessing many farming factors and weighing in on soil
health, crop yield, and longevity. They must decide which crops will
bring in the most money over an allotted amount of time as well as
keeping track of their nitrogen levels and long term productivity.
The following page will offer a sample and criteria for allotting growing
parameters for the students. This projects involves math, so you may
want to modify the level to the ability of your students.
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Students will be building square fields
for the step-by-step project that they will use for conducting experiments. Students will be comparing a four-field area by simulating an
area that uses crop rotation to one that does not. In order to accurately
participate in this experiment the instructor and the class must understand a few design constraints. The instructor may choose all or some
of the following in accord with the ability of his/her students.
$90 /ton
$50 /ton
$70 /ton
$60 /ton
$30 /ton
Corn
Wheat
Sunflowers
Tomatoes
Watermelon
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50
25
40
20
60
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Alfalfa
Pinto beans
Soybeans
Field peas
Sweetclover
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Nitrogen Fixers (add nitrogen) Heavy Nitrogen Users
Medium Nitrogen Users
20
25
20
20
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Barley
Durum
Oats
Winter wheat
$110 /ton
$90 /ton
$90 /ton
$60 /ton
50
40
35
60
70
$170 /ton
$160 /ton
$140 /ton
$275 /ton
$300 /ton
Light Nitrogen Users
Turnips
10 $80 /ton
Sweet potatoes
5 $60 /ton
Peppers
10 $100 /ton
Pumpkins
15 $100 /ton
#8
Year one, all fields are of Medium soil level or at 35 nitrogen units.
This limits the options for planting.
Year 1
Turnips
yield nitrogen = 25
Barley after
yield nitrogen = 15
Alfalfa after
yield nitrogen = 85
Soybean
yield nitrogen = 75
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• Fields have a value rating of High, Medium and Low that corresponds
to each square of a four-field area. High soils have 75 nitrogen units,
Medium have 35 and Low have 15 nitrogen units.
• It costs $30 to reseed a field to plant a new crop for the next year
• Each crop and field has a specific nitrogen level. Some crops add
nitrogen and some remove it. The chart provided gives this data.
• If a field has less nitrogen than the crop to be planted requires, the
crop will not grow, and it will yield $0.
• If two of the same crop are planted next to each other one year, the
yields are reduced by 1/2 due to pests. Diagonal planting causes no
problems. Planting the same crop in the same area year to year
reduces yield to 1/4.
Sample:
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Background Continued:
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Teacher Guide
CROP ROTATION
Math Sample:
Turnips use 10. 35-10=25 nitrogen left. Value $80
Barley uses 20. 35-20=15 nitrogen left. Value $110
Alfalfa adds 50. 35+50=85 nitrogen left. Value $90
Soybeans adds 40. 35+40=75 nitrogen. Value $70
Total Income for the year $350
Year two, all fields start at a new nitrogen level. If you decide to
charge students for reseeding subtract $120 for seeding all fields
Year 2
Start 25
Pumpkins
yield=10
Start 15
Sweetclover
yield=75
Start 85
Watermelon
yield=15
Start 75
Corn
yield=25
(Year 1 Starting $350 - $120 reseeding = $230)
Pumpkins use 15. 25-15=10 nitrogen left. Value $100
Sweetclover adds 60. 15+60=75 nitrogen. Value $30
Watermelon uses 70. 85-70=15 nitrogen. Value $300
Corn uses 50. 75-50=25 nitrogen.
Value $170
Total Income for the year $600
Year three, all fields start at a new nitrogen level. In this example
the student makes a mistake on rotation and puts crops together.
Year 3
Start 10
Peppers
yield=0
Start 75
Watermelon
yield=5
Start 15
Peppers
yield=5
Start 25
Alfalfa
yield=75
(Year 2 cumulative total (yr 1.$230 + yr 2$600) seeding $120 = $710 )
Peppers use 10. 10-10=0 nitrogen. Value $100/2=$50
(1/2 yield for being next to another pepper field)
Watermelon use 70. 75-70=5 nitrogen.
Value $30
Peppers use 10. 15-10=5 nitrogen. Value $100/2=$50
Alfalfa adds 50. 25-50=75 nitrogen.
Value $90
Total Income for the year
$220
Three-year total without reseeding costs: $1,170
Three-year total with reseeding costs:
$ 930
Copyright ©2006 PCS Edventures, Inc. Use of this material is restricted to BrickLab
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Vocabulary Review:
Students should be able to
identify and explain terms in their own words.
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AGRICULTURE
CROP ROTATION
FERTILIZER
NITROGEN FIXING
YIELD
WRITTEN EXTENSION: Students will research and
write a short essay about some pros and cons of chemical fertilizers. Students may read their essays to the class
Activities:
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INVESTIGATE AND DISCUSS: The instructor will
lead a class discussion about farm technology and the concept of crop rotation. Ask students if they know anyone
who farms and what the farmer grows and how they do it.
Discuss the importance of farming. Discuss how only 1-2%
of people grow food for everyone in the United States*.
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CHALLENGE: Students will use the models built in project
1 to try to earn enough money in four years to repair a
tractor. Repairs costs $1,300. Students may create a “field”
using any crop listed in the chart. Use the handout on
page 84. Instructors may add limitations as they wish.
REAL WORLD EXTENSION: If possible, have students
visit a farm, farmers market, supermarket, or greenhouse.
Have students look at where the produce comes from and
have them think about all the technology needed to grow,
transport, and preserve the food.
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#8
SMALL GROUP EXTENSION: Students will organize
themselves into several small groups. Each group will
research a specific country for the agricultural products it
grows and exports by using the Internet or an atlas. Once
each group is finished with research, have them design a
four-field crop rotation that would be the most productive and
cost-effective. Students will present their results to the class.
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•
•
•
•
•
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Teacher Guide
CROP ROTATION
FUN & INTERESTING FACTS
Here are some great agricultural facts!
1. Crop Threats: United States farmers face the threat
of approximately 10,000 species of crop destroying
insects, 1,800 types of weeds and 1,500 different plant
diseases.
2. Farmable Land: The United States, India, and China
account for a third of all arable (farmable) and
permanent cropland in the world.
*Adjust for your own country
Copyright ©2006 PCS Edventures, Inc. Reproduction of this material is restricted to BrickLab owners. Unauthorized distribution is strictly forbidden.
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CROP ROTATION
Required Materials:
2 - worksheets
per student.
Build Crops and Try a Rotation!
1. With a partner you will build
field icons with 2x4 and 2x2
bricks. In order to get the crop
to stay together be sure to
attach the bricks in the order
shown.
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Check off when complete
4. Place four different crops on
the worksheet and calculate
your income. Good crop rotation does not duplicate crops.
How much nitrogen does each
crop use? What happens if you
put watermelon in the same
place two years in a row?
?
Check off when complete
5. Your instructor will assign
you a starting nitrogen level
for each field. Use only the
crop icons listed in this lesson
to try to get the most yield ($).
Use crop rotation and do not
duplicate crops. What was the
result $_____________
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Date:
Red = Watermelon
Green = Peppers
Yellow = Winter Wheat
Blue = Soybean
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2. Create eight more crops:
two blue, two red, two yellow,
and two green.
Check off when complete
2x2
This icon represents corn
Check off when complete
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96 - 2x4
bricks
3. Collect two of the same
handout from your instructor
and look at the chart. Choose
three more crops and create
an icon for each one.
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24 - 2x2
bricks
(Workbook page 51.)
#8
Name:
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Project Plans
Low
Check off when complete
Copyright ©2006 PCS Edventures, Inc. Reproduction of this material is restricted to BrickLab owners. Unauthorized distribution is strictly forbidden.
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Heavy Nitrogen Users
Nitrogen Value
+/per ton
Crop
Medium Nitrogen Users
Nitrogen Value
Crop
+/per ton
Crop
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Nitrogen Fixers (add nitrogen)
Light Nitrogen Users
Nitrogen Value
Crop
+/per ton
+50
$90
Corn
-50
$170
Barley
-20
$110
Pinto bean
+25
$50
Wheat
-40
$160
Durum
-25
$90
Sweet potatoes
Soybean
+40
$70
Sunflowers
-35
$140
Oats
-20
$90
Field pea
+20
$60
Tomatoes
-60
$275
Winter wheat
-20
$60
Sweetclover
+60
$30
Watermelon
-70
$300
Nitrogen Value
+/per ton
-10
$80
-5
$60
Peppers
-10
$100
Pumpkins
-15
$100
Turnips
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Alfalfa
Name:
Project Plans
#8
CROP ROTATION PLANNING SHEET
Place your four crops here. Year ________
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Copyright ©2006 PCS Edventures, Inc. Reproduction of this material is restricted to BrickLab owners. Unauthorized distribution is strictly forbidden.
Date:
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IC
Place your four crops here. Year ________
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CROP ROTATION
Watermelon
Corn
Watermelon
Soybean
Year 2
Peppers
Sunflowers
Watermelon
Tomatoes
IC
2. Nitrogen fixing plants take nitrogen out of the soil.
† True
† False
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4. Material added to the soil to encourage plants to grow is
called...
† Watering
† Crops
† Fertilizer
6. What role does nitrogen play in farming? Why does technology
focus on making new fertilizers?
_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
7. What are three things that affect crop yield?
Affects Crop Yield:
1.
________________________________
2.
________________________________
3.
________________________________
Grade
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Date:
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3. The practice or study of farming is called...
† Planticulture
† Agriculture
† Farmicology
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_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
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Year 2
5. Why is crop rotation an important technology?
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1. What would improve Farmer John’s two-year crop plan? You
may use the chart for assistance. Write your new plan below.
Year 1
Year 1
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Name:
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Assessment
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