homework #3
.docx
keyboard_arrow_up
School
North Dakota State University *
*We aren’t endorsed by this school
Course
210
Subject
Material Science
Date
Jan 9, 2024
Type
docx
Pages
4
Uploaded by PrivateGoose4069 on coursehero.com
PLSC 210 Horticulture Science
Name____________________________
Fall Semester, 2010
Homework #3
(Total 25 points, due November 12, show calculations for full credit)
1.
You have a 50 lb bag of 20-20-20 commercial analysis (general purpose) fertilizer.
a.
Indicate the amounts of each fertilizer (in oxide form) contained in the 50 lb bag. (
2 points
)
Answer: N = _______ lb,
P
2
O
5
= _______ lb,
K
2
O =_______ lb
Calculations
:
b.
What is the elemental analysis of this fertilizer?
(
2 points
)
Answer:
Elemental analysis ______ - _______ - _______
N - P - K.
Calculations
:
c.
How many lb of each fertilizer element (elemental analysis) is contained in the 50 lb bag? (
2 points
)
Answer:
N =_______ lb,
P =_______ lb,
K =_______ lb
Calculations
:
2.
You would like to fertilize your potted plants with a nutrient solution containing 200 ppm nitrogen (N),100
ppm phosphorus (P
2
O
5
) and 250 ppm potassium (K
2
O) using a 100-gallon stock tank which is installed
with a 1:200 proportion injector. Your fertilizers are ammonium nitrate (NH
4
NO
3
), potassium mono-
phosphate (KH
2
PO
4
) and potassium chloride (KCl).
Commercial analysis (N-P
2
O
5
-K
2
O):
NH
4
NO
3
(33.5-0-0), KH
2
PO
4
(0-53-34), KCl (0-0-62) (see Table 1)
Conversion factors:
P/ P
2
O
5
= 0.44, K/K
2
O = 0.83
a.
How many lb of each fertilizer should you use for the 100-gallon stock tank?
(
3 points
)
Answer: NH
4
NO
3
=________ lb,
KH
2
PO
4
=_________ lb,
KCl=_________ lb
Calculations
:
b.
What are the concentrations of elemental nitrogen (N), phosphorus (P) and potassium (K) of your stock
solution and the final fertilizer solution being applied?
(
3 points
)
Answer:
1) Final fertilizer solution:
N =__________ ppm, P =___________ ppm, K =___________ ppm
2) Stock solution:
N =__________ ppm, P =___________ ppm, K= ___________ ppm
Calculations
:
c.
You have 5,000 pots of chrysanthemums in your greenhouse and each pot requires 0.5 gallon of
fertilizer solution per day.
How many days would the stock tank (100 gallon) last after it has been
filled once with your fertilizer stock?
(
2 points
)
Answer:
1) Total volume of final solution:_____________ gallon
2) Total number of days:
_____________ days
Calculations
:
d.
Using Table 1, calculate the cost of fertilizer needed to fill your stock tank and feed your crop. (
3
points
)
Answer:
1) Cost of fertilizers
$_____________/100-gallon stock tank
2) Cost of fertilizers
$_____________/5,000 pots per month
3) Cost of fertilizers
$_____________/pot per month
Calculations
:
Costs of chemical fertilizers:
Commercial
Cost per
Fertilizer
Formula
analysis
50- lb bag
Ammonium nitrate
NH
4
NO
3
33.5-0-0
$20.50
Potassium mono-phosphate
KH
2
PO
4
0-53-34
$22.30
Potassium chloride
KCl
0-0-62
$15.50
3.
You would like to prepare 100 liter of 200 ppm nitrogen (N) using magnesium nitrate [Mg(NO
3
)
2
6H
2
O].
How many grams of this fertilizer should be used in 100 liter?
(
4 points
)
Answer:
Magnesium nitrate needed:
_________________ g/100 liter.
This solution will contain:
_________________ ppm Mg.
Calculations
:
4.
How many ounce (oz) of a 20-20-20 commercial fertilizer or potassium nitrate (KNO
3
) should be
dissolved in 100 gallon of water to make a 200 ppm nitrogen (N) solution? (
4 points
)
(Note: 1 oz/100 gallon = 75 ppm)
Answer:
20-20-20 fertilizer:
________________ oz/100 gallon.
KNO
3
:
________________ oz/100 gallon.
Calculations
:
Note
1 gallon=3.8 liter, 1 kg=2.2 lb, 1 oz=29 g
1 kg=1,000 g=1,000,000 mg
Atomic weights:
N=14.01, P=30.98, K=39.1, Mg=24.32, S=32.07, Ca=40.08
H=1.01, C=12.01, O=16.0
Molecular weights:
KNO
3
=101.11
Mg(NO
3
)
2
6H
2
O=256.4
Commercial analysis:
Mg(NO
3
)
2
6H
2
O=11-0-0
KNO
3
=13-0-44
2
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help