Granular Fertilizer

Using Platforms for Granular Fertilizer

The use of a platform for granular fertilizer and is usually less time consuming and more economical.  Platforms are especially useful in ponds 10 acres or larger, but may also be used in smaller ponds.  The fertilizer should be poured directly onto a submersed platform, which allows nutrients to dissolve slowly in the surface water.  The amount of fertilizer required to maintain a desirable growth of plankton may be reduced 15 to 25 percent when platforms are utilized. One platform is adequate to fertilize 25 surface acres of water.  A platform 3 x 3 feet or 9 square feet will hold the fertilizer needed for a 3-acre pond.  In larger ponds, provide 3 1/2 square feet of platform for each surface acre of water in ponds larger than 3 acres.  For example, a 10-acre pond needs 35 square feet of platform area or one platform measuring 5 x 7 feet.  Two platforms with a total surface area of 140 square feet are needed in a 40-acre pond.

The platform should be placed in the upper end of the pond, about 10-15 feet from the bank, where wave action will provide good distribution of the dissolved nutrients.  A walkway should lead from the bank to the platform, or the platform may be installed beneath a fishing pier.  The floor of the platform should be 12 to 18 inches under the water and should be adjustable to allow for water level fluctuation.  Platforms may be constructed of wood or concrete.  If wood is used, it should be treated with preservative to improve longevity.

Other Ways to Apply Granular Fertilizer

Granular fertilizer may also be applied by placing bags in water two to three feet deep along the shore in the upper end of the pond.  The bags should be placed on the pond bottom and the topside of the bag removed.  A layer of the bag should remain between the fertilizer and the pond bottom.  The fertilizer should not be allowed to come in contact with the mud.  Plywood or plastic sheets may also be used between the fertilizer and pond bottom.  The shoreline method is similar to the platform in principle, but may not be as efficient.

The information above came from the Alabama Wildlife and Freshwater Fisheries Division's booklet Sportfish Management in Alabama Ponds, which is available as a PDF.