CUMMINGS: AGRONOMY EXAM 3 WITH VERIFIED ANSWERS #10
1. About how many total pounds of fertilizer is needed to cover 180 acres at a rate of 50 pounds of
nitrogen per acre with a 33-20-5 fertilizer?: 27,273 lbs
2. A farmer applied 12,875 lbs of 35-40-20 to 103 acres. How many lbs of nitrogen /acre were
applied?: 43.8
3. How much will it cost to treat 100 acres with 46-0-0 at a rate of 35 pounds nitrogen/acre if 46-0-0
is $340 ton?: $7,609
4. How much will it cost to treat 51.6 A at 35 lbs of N / A with 21-0-0 if 21-0-0 is
$240 ton?: $1,032
5. I need to fertilize 30 acres of bermudagrass at a rate of 50 lbs nitrogen/A. How many pounds of
15-20-0 will be applied per acre?: 333
6. I need to fertilize 30 acres of bermudagrass at a rate of 50 lbs nitrogen/A. How many pounds of
15-20-0 fertilizer will I need for the 30 acres?: 10,000
7. If you applied 200 pounds of 40-20-5 fertilizer to 1 acre, how much total K2O would be applied to 1
acre?: 10 lbs
8. The formula for ammonium phosphate is:: (NH4)3PO4
9. The formula for ammonium sulfate is:: (NH4)2SO4
10.How much 28-3-10 is required to apply 1 lb N/1000ft² to 9,000ft²?: 9,000ft² * 1lb N/1000ft² *
1/0.28 = 32
11.How much will it cost to treat 51.6 A with 46-0-0 at a rate of 35# N/A if46-0-0 is $340 / ton?: 3926lb
* ton/2000lb * $340/ton = $667
12.Soil test indicates the 103 acre field needs 50 pounds of P2O5/A for corn. How much 35-4-20 is
needed?: 128,750 pounds
13.If you apply 250 pounds of 30-26-7 to 1 acre, how much K2O will be applied per acre?: 17.5 lbs
14.If you have 50 lbs of 15-5-10, how many lbs of P2O5 do you have?: 50 * 0.05
= 2.5
15.How much 28-3-10 is required to apply 1 lb N/1000ft² to 10,000ft²?: 10,000ft²
* 1lb N/1000ft² * 1/0.28 = 36
16.In class we looked at photos of a wilting tomato. Why was the tomato wilting?: Roots were
exposed to sunlight
17.In order to supply 65 # N / A to a hay field, which statement is true about using either urea or
ammonium sulfate?: Would take fewer pounds of 46-0-0 (urea)
18.which of the following can limit growth?: (all of the above) light
phosphorus
water space
nitrogen
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1. About how many total pounds of fertilizer is needed to cover 180 acres at a rate of 50 pounds of
nitrogen per acre with a 33-20-5 fertilizer?: 27,273 lbs
2. A farmer applied 12,875 lbs of 35-40-20 to 103 acres. How many lbs of nitrogen /acre were
applied?: 43.8
3. How much will it cost to treat 100 acres with 46-0-0 at a rate of 35 pounds nitrogen/acre if 46-0-0
is $340 ton?: $7,609
4. How much will it cost to treat 51.6 A at 35 lbs of N / A with 21-0-0 if 21-0-0 is
$240 ton?: $1,032
5. I need to fertilize 30 acres of bermudagrass at a rate of 50 lbs nitrogen/A. How many pounds of
15-20-0 will be applied per acre?: 333
6. I need to fertilize 30 acres of bermudagrass at a rate of 50 lbs nitrogen/A. How many pounds of
15-20-0 fertilizer will I need for the 30 acres?: 10,000
7. If you applied 200 pounds of 40-20-5 fertilizer to 1 acre, how much total K2O would be applied to 1
acre?: 10 lbs
8. The formula for ammonium phosphate is:: (NH4)3PO4
9. The formula for ammonium sulfate is:: (NH4)2SO4
10.How much 28-3-10 is required to apply 1 lb N/1000ft² to 9,000ft²?: 9,000ft² * 1lb N/1000ft² *
1/0.28 = 32
11.How much will it cost to treat 51.6 A with 46-0-0 at a rate of 35# N/A if46-0-0 is $340 / ton?: 3926lb
* ton/2000lb * $340/ton = $667
12.Soil test indicates the 103 acre field needs 50 pounds of P2O5/A for corn. How much 35-4-20 is
needed?: 128,750 pounds
13.If you apply 250 pounds of 30-26-7 to 1 acre, how much K2O will be applied per acre?: 17.5 lbs
14.If you have 50 lbs of 15-5-10, how many lbs of P2O5 do you have?: 50 * 0.05
= 2.5
15.How much 28-3-10 is required to apply 1 lb N/1000ft² to 10,000ft²?: 10,000ft²
* 1lb N/1000ft² * 1/0.28 = 36
16.In class we looked at photos of a wilting tomato. Why was the tomato wilting?: Roots were
exposed to sunlight
17.In order to supply 65 # N / A to a hay field, which statement is true about using either urea or
ammonium sulfate?: Would take fewer pounds of 46-0-0 (urea)
18.which of the following can limit growth?: (all of the above) light
phosphorus
water space
nitrogen
1/4
