"Liming provides major benefits if you are growing sportfish in a pond in an area with acid soils," he said. Limestone reduces the acidity of bottom soils and makes nutrients more available for the food chain that supports the fish.
Another benefit of liming is increased dissolved minerals in the water, which reduces stress on the fish over the winter. Fish in acidic water with low hardness are more likely to get sick.
Late fall and winter are the best times to lime. This gives time for the lime to react with the bottom mud and to counteract the acid soil before the next growing season. Lime should not be applied at the same time as fertilizer; the calcium in the lime reduces the effectiveness of the fertilizer by precipitating the phosphorus out of the water.
"If the soils on pastures or fields near your pond require lime, the pond would likely benefit from liming as well," said Allen.
If you have not limed before, here are a few common questions answered by Allen:
Would my pond benefit from agricultural limestone?
The key is alkalinity. Contact your county extension office to have the total alkalinity of your pond water tested. If it is below 20 parts per million, liming would benefit your fish population.
How much agricultural limestone should I use?
This is determined by soil testing, which is also offered by the Cooperative Extension Service. In general, ponds that need lime will require at least one ton per acre.
Is all lime the same?
No! Make sure to use only agricultural limestone in ponds with fish populations. Other forms of lime -- hydrated, slaked or quick -- can be used to lime empty ponds before fish are stocked, but if they are used in filled ponds, they cause the pH to increase dramatically, killing fish.
An application of agricultural limestone typically lasts for three to four years, depending on the amount of water that flows through the pond.
An Extension publication, MP360, "Farm Pond Management for Recreational Fishing," offers more information online at www.uaex.edu/Other_Areas/publications/PD....
For more information, visit www.uaex.edu or contact your local county agent.