Debbie Archer | School of Agriculture, Fisheries and Human Sciences
PINE BLUFF, Ark. – Spring is finally here and farm pond owners may be wondering if they need to fertilize their ponds. In fact, there is little reason to fertilize most ponds, according to Dr. Nathan Stone, Extension fisheries specialist at the University of Arkansas at Pine Bluff.
Initiating a fertilization program is recommended only when the pond owner desires more and bigger fish, the pond is not already fertile, and the pond has been properly stocked, Dr. Stone said. Typically, infertile ponds still support 40 to 200 pounds of fish per acre, more than most people can use.
Ponds where the fish population is out of balance may not provide good fishing even if they are fertilized. Ponds with existing dense plankton blooms, or that are muddy, weedy, or ponds that have excessive water flow should not be fertilized until the problem is corrected. “Fertilizing when nuisance weeds are already established is like throwing gasoline on a fire,” Dr. Stone said.
“If fish in ponds will be fed, usually there is no need to fertilize, as the uneaten feed and fish wastes will serve as fertilizer. While some increase in fertility may be beneficial, too many nutrients lead to dense algae blooms, oxygen depletions and even fish kills.”
Water in ponds with heavy algae populations is less palatable to livestock, and animals may drink less, reducing growth. Also, livestock should not be allowed to drink in areas with heavy algae scums, given the potential for poisoning from toxic algae, he said.
Before fertilizing a pond, the alkalinity of the water should be tested to see if the pond would benefit from the addition of agricultural lime. If the soils on pastures or fields near your pond require lime, it is likely that the pond would benefit from liming as well. Alkalinity is easily measured with a relatively inexpensive test kit or a water sample can be sent for testing through your local University of Arkansas Cooperative Extension Service office.
“It’s important to carefully consider whether your pond would benefit from a fertilization program or not,” Dr. Stone said. “If you decide to fertilize, follow recommended guidelines. Improper or excessive fertilizer applications can pollute natural waters, especially for ponds located in ecologically sensitive watersheds.”
For additional information on pond management, contact your University of Arkansas Cooperative Extension Service office, and consult publication MP360, “Farm Pond Management for Recreational Fishing.”