With spring just around the corner and water temperatures on the rise, pond owners should proceed to the next level of their continual improvement program. The water tests from January and pH correction in February have prepared ponds for nutrient enrichment to fuel micro-organism growth and overall pond productivity.
Beginning at the microscopic level, fertilizer treatments promote growth of phytoplankton that are eaten by water insects and continue up the food chain resulting in big fat bream and lunker bass. A fertilized pond will provide three to four times the fish as an unfertilized pond, or 300 to 400 pounds per acre.
Fertilizer should be available throughout the growing season; a series of treatments can be made, or the pond can be treated at one time using a time-released version. Treatments should be scattered throughout the pond. The first application should be in early March, just as the growing season begins and waters begin to warm. Soon after the fertilizer treatments and the first bloom, the water clarity will decrease. As the water clears up and visibility increases to greater than two feet, secondary treatments can begin.
The key ingredient in pond fertilizers is phosphate. Treatments should contain a high ratio of phosphate, such as 0-46-0. As a general rule, granular or powdered fertilizer can be added at a rate between five and seven pounds per acre. If liquid fertilizers are used, they should be diluted before distribution and should be prescribed at a similar ratio.
If the pH has not been corrected with limestone treatments, fertilizers should not be added. Phosphate amendments will only be effective if pond pH is approaching 7 or above. Water pH should always be corrected prior to fertilization.