14 MISC. PUB. 528, U. S. DEPT. OF AGRICULTURE 
Nonmixed chemical fertilizer. 
Neutral or acid waters: 
40 pounds sulfate of ammonia 
60 pounds superphosphate (16 percent) 
5 pounds muriate of potash 
45 pounds finely ground limestone 
Mix all ingredients before applying. 
Alkaline waters (Above pH=§8): 
40 pounds sulfate of ammonia 
60 pounds superphosphate (16 percent) 
5 pounds muriate of potash 
Mix all ingredients before applying. 
The unmixed fertilizers cost less than the standard mixtures and 
should be used when many ponds or a large pond is to be fertilized. 
Superphosphate is offered in various strengths of available phos- 
phoric acid; these may be used in the following quantities: 
60 pounds superphophate, 16 percent 
30 pounds superphosphate, 32 percent 
20 pounds superphosphate, 48 percent. 
The 6-8-4 mixture is a cotton fertilizer and is easily obtained in the 
Southeastern States. Elsewhere it is not used extensively and often is 
not available. Other commercial mixtures may be used: 
1. 100 pounds 4-84 mixture* 
20 pounds nitrate of soda or sulfate of ammonia 
2. 100 pounds 3-8-3 mixture 
25 pounds nitrate of soda or sulfate of ammonia 
38. 100 pounds 3-8-5 mixture 
25 pounds nitrate of soda or sulfate of ammonia - 
4, 50 pounds 8—-16—-8 mixture 
20 pounds nitrate of soda or sulfate of ammonia 
5. 100 pounds 8-84 mixture 
The nitrate of soda should be used where waters are neutral or acid, 
and the sulfate of ammonia where waters are alkaline. In alkaline 
waters the acidity developed by the sulfate of ammonia will be neu- 
tralized by the lime or other alkaline compounds that are present. 
These quantities are sufficient for one application for 1 acre of pond 
surface. ‘They must be increased or decreased accordingly as the pond 
is larger or smaller than 1 acre. Ponds that overflow should receive 
the first application as soon as the spring flood season is past; ponds 
with little or no overflow should receive the first application early in 
the spring. Follow the first fertilization with two or three more at 
weekly intervals. Soon after the first or second application, the 
growth of plankton will cause clear water to be murky and of a green 
or brown color. This murky condition, which obscures the bottom, 
is an indicator ot fertility. When the bottom can be seen at a depth of 
18 inches, another application of fertilizer is needed. After the third 
or fourth weekly application, fertilizer is added about every 4 weeks 
or whenever the bottom is visible in 18 inches of water. Fertilization 
is continued until September or October, by which time a total of 8 to 
14 applications will have been required. 
In ponds up to 4 or 5 acres in area, the fertilizer is applied by broad- 
casting it from the shore toward the center (fig. 4). In larger ponds, 
it is broadcast from a boat over the areas where the water is from 1 to 
6 feet deep. It should not be distributed in areas deeper than 6 feet. 
“This fertilizer or 4-10-4 may be more readily available than 6-8-4 and if applied at 
more frequent intervals will not require the addition of nitrate of soda or sulfate of 
ammonia, 
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