Section: Plant & Soil Science
Unit: Soil Management
Lesson Title: Lesson 3: Fertilizer
Recommendations and Fertilizer Adjustments Lab

Slide #1
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You are making 200 cookies:
You have the following quantities of ingredients
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3/4 lbs of butter 2 teaspoons of salt
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1 ½ cups of brown sugar 1 teaspoon of baking soda
2 cups of sugar 1 cup of chopped nuts
5 eggs
2 teaspoons of vanilla
6 cups of chocolate chips
8 cups of flour

Adequate
Deficient
Excessive
Slide #2
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You had the following quantities of ingredients
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3/4 lbs of butter 2 teaspoons of salt
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1 ½ cups of brown sugar
2 cups of sugar
5 eggs
2 teaspoons of vanilla
8 cups of flour
1 teaspoons of baking soda
1 cup of chopped nuts
6 cups of chocolate chips
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You need the following quantities of ingredients
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1 lb of butter
2 cups of brown sugar
2 teaspoons of salt
2 teaspoons of baking soda
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2 cups of sugar
4 eggs
2 cups of chopped nuts
4 cups of chocolate chips
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3 teaspoons of vanilla
4.5 cups of flour

Slide #3
Student Learning Objectives (Enablers)
As a result of this lesson, the student will:
2.
1.
Use given data to make fertilizer recommendations for crops in
Colorado.
Be able to complete the fertilizer recommendation part of the Colorado
Land Classification CDE.

Slide #4
Fertilizer Recommendations for Irrigated Corn, Sorghum, and
Sudan
Soil Test
NO
3
-N
Ppm
0-0.5
NITROGEN*
Soil Test % Soil Organic Matter
06-1.0
1.1-1.5
1.6-2.0
>2.0
(lbs/A fertilizer N)
0-6
7-12
13-18
19-24
25-30
31-36
37-42
43-48
>48
70
40
0
250
220
190
160
130
100
55
0
0
235
205
175
145
115
85
40
0
0
220
190
160
130
100
70
205
175
145
115
85
55
0
0
0
190
160
130
100
70
40
0
0
0

Slide #5
Fertilizer Recommendations for Irrigated Corn, Sorghum, and
Sudan
Phosphorous
Soil Test P
(ppm)
0-3
4-7
8-11
>11
Fertilizer P
Lbs/A P
2
O
5
80
50
30
0

Slide #6
Fertilizer Recommendations for Irrigated Corn, Sorghum, and Sudan
Potassium
Soil Test K
(ppm)
0-60
61-120
>120
Fertilizer K
Lbs/A K
2
O
64
40
0

Zinc recommendations for all crops
Soil Test
ZINC
PPM
0-0.9
1.0-1.5
>1.5
0-0.5
>0.5
Irrigated
ZINC
Dryland
(lbs/A fertilizer Zn)
5
0
10
5
0
Sensitive Crops
(corn, sorphum, sudan, beans, potatoes)
5
0
0
Other Crops
0
0
Slide #7

(ppm)
0-3.0
3.1-5.0
>5.0
Soil Test Fe
Slide #8
Iron recommendations for all crops
Iron
Iron recommendation
Fe Sensitive crops only
(corn, sorghum, sudan, beans, potatoes
Soil is deficient in available FE and corrective application will likely be beneficial.
Soil is marginally deficient in available iron and application may or may not be necessary.
No Fe fertilization is required

Crop
Sensitive
Pinto beans, potatoes
Moderately tolerant
Corn, sugarbeets, millet, oats, alfalfa seeding, all grasses
Tolerant
Sorghum, barley, wheat, sudangrass, established alfalfa, forage sorphum x sudan
0-6.0
Low
Soluble Salts
Moderate
Electrical Conductivity
(mmhos/cm)
0-2.5
0-4.0
2.6-5.0
4.1-8.0
6.1-12.0
High
Slide #9
>5.0
>8.0
>12.0

Land Judging Scorecard
FERTILIZER TREATMENT
(5 points each)
Recommendations in lbs/A
_____ NO3-N
_____ P2O5
_______ K2O
_____ Zn
_____ Fe
SOLUBLE SALT LEVEL
(5 points)
 low
 moderate
 high
Slide #10

Crop to be fertilized------------Irrigated Corn
Organic matter content-------1.0%
Nitrogen soil test--------------25 ppm
Phosphorous soil test---------7 ppm
Potassium soil test------------121 ppm
Zinc soil test--------------------0.8 ppm
Iron soil test--------------------5.1 ppm
Soluble salt reading-----------7.9mmhos/cm
Slide #11

115 lbs/A of N03-N
50 lbs/A of P2O5
0 lbs/A of K2O
10 lbs/A of Zn
0 lbs/A of Fe
Moderate level of Soluble Salts
Slide #12

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Step 1. Find Organic Matter and Write it here____________________
Step 2. Find the Nitrogen PPM and write it here__________________
Step 3. Using both numbers on the chart write your initial N rec. here______________
Step 4. Subtract yield goal from 150 and write number here___________________
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Step 5. If step 4 answer is zero then write step 3 answer on score sheet.
Step 6. If step 4 answer different then zero go to step 7.
Step 7. Take Step 4 answer divided by 25 and write answer here________________
Step 8. Take step 7 answer and multiply by 40 and write answer here______________
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Step 9. If yield goal is greater than 150 ADD step 8 answer to step 3 number and write total answer on score sheet.
Step 10. If yield goal is less than 150 SUBTRACT step 8 answer from step 3 answer and write total answer on score sheet.

Fertilizer Worksheet for corn, sorghum, and sudan used for silage
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Step 1. Find Organic Matter and Write it here____________________
Step 2. Find the Nitrogen PPM and write it here__________________
Step 3. Using both numbers on the chart write your initial N rec. here______________
Step 4. Subtract yield goal from 30 and write number here___________________
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Step 5. If step 4 answer is zero then write step 3 answer on score sheet.
Step 6. If step 4 answer different then zero go to step 7.
Step 7. Take Step 4 answer divided by 10 and write answer here________________
Step 8. Take step 7 answer and multiply by 40 and write answer here______________
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Step 9. If yield goal is greater than 30 ADD step 8 answer to step 3 number and write total answer on score sheet.
Step 10. If yield goal is less than 30 SUBTRACT step 8 answer from step 3 answer and write total answer on score sheet.

Fertilizer Worksheet for Irrigated grass, grass legume hay, pasture and mountain meadows.
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Step 1. Find Organic Matter and Write it here____________________
Step 2. Find the Nitrogen PPM and write it here__________________
Step 3. Using both numbers on the chart write your initial N rec. here______________
Step 4. Subtract yield goal from 4 and write number here___________________
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Step 5. If step 4 answer is zero then write step 3 answer on score sheet.
Step 6. If step 4 answer different then zero go to step 7.
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Step 7. Take Step 4 answer multiply by and write answer here________________
Step 8. If yield goal is greater than 4 ADD step 7 answer to step 3 number and write total answer on score sheet.
Step 9. If yield goal is less than 4 SUBTRACT step 7 answer from step
3 answer and write total answer on score sheet.

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Step 1. Find Organic Matter and Write it here____________________
Step 2. Find the Nitrogen PPM and write it here__________________
Step 3. Using both numbers on the chart write your initial N rec. here______________
Step 4. Subtract yield goal from 50 and write number here___________________
Step 5. If step 4 answer is zero then write step 3 answer on score sheet.
Step 6. If step 4 answer different then zero go to step 7.
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Step 7. Take Step 4 answer divided by 10 and write answer here________________
Step 8. Take step 7 answer and multiply by 25 and write answer here______________
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Step 9. If yield goal is greater than 50 ADD step 8 answer to step 3 number and write total answer on score sheet.
Step 10. If yield goal is less than 50 SUBTRACT step 8 answer from step 3 answer and write total answer on score sheet.