FERTILIZING THE POND 



Figure 11. — Ponds often need to be fertilized to increase their productivity. 



manure can be used at half the rate 

 of fresh manure. The proper time 

 of application is 2 weeks before the 

 pond is to be stocked so that a 

 heavy food crop is ready for the 

 fish. 



During the growing season, the 

 food supply is maintained by peri- 

 odic applications of dried sheep 

 manure. The applications should 

 be made at 2- to 3-week intervals 

 all summer. Ponds should be fer- 

 tilized at the optimum rate rather 

 than the maximum because an ex- 

 cess is a waste of fertilizer and the 

 decomposition of a large quantity 

 of fertilizer may reduce the oxygen 

 content of the water enough to 

 cause suffocation of the fish. 



AVhen soft-water ponds are fer- 

 tilized, it will be necessary to add 

 agricultural limestone to the water 

 to maintain proper alkalinity. A 



rule-of-thumb for liming ponds is 

 to add half as much limestone as 

 fertilizer. 



In the Southern States, fertiliz- 

 ing should be started during the 

 first warm w^eather of spring, and 

 should be continued through the 

 summer and early fall. In the far 

 South it may be advisable to fer- 

 tilize monthly during the winter. 



In fertilizing a pond, supply 

 enough nutrients to the water to 

 induce the growth of microscopic 

 plants, which give the water a 

 green or brown tinge. It is neces- 

 sary to apply the fertilizer fre- 

 quently enough to build up a sur- 

 plus of minerals. Applications 

 should be made at weekly or 10-day 

 intervals and should be continued 

 until the water becomes so turbid 

 (as a result of these microscopic 

 organisms) that the bottom cannot 



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