A recent testing of the water quality of 318 farm ponds in 32 East Texas counties showed the water quality of more than one-fifth of the ponds needed improvement.
County Extension agents with Texas Cooperative Extension performed the testing on the ponds, which represented nearly 1,200 acres of surface water and 254 landowners.
Because East Texas soils are highly acidic and most farm ponds are watershed ponds fed by runoff, the most common problem is acidity or low pH. Water sample testing, performed by the county agents, showed 68 of the ponds needed from one to three tons of agricultural limestone per surface acre to correct the acidity, said Billy Higginbotham, wildlife and fisheries specialist with Extension.
Higginbotham supplied 50 water quality test kits and trained agents in their use through a Renewable Resources Extension Act Grant. With the kits in hand, Extension agents could test for pH and total alkalinity. Higginbotham also provided test kits to check oxygen levels in case landowners were seeing fish die offs.
“The main value of farm ponds results from the fish population,” Higginbotham said. “Fish can rarely survive a pH below 4.0 or above 11.0.
However, pH alone cannot be used to determine how much limestone a pond needs. The testing must include measuring alkalinity.”
Though it is extremes in pH that may kill fish, the need for testing alkalinity arises from a farm pond's water pH fluctuating widely during a day for several reasons. For example, as pond vegetation responds to sunlight, the photosynthesis process traps carbon dioxide and releases oxygen.
“This reduction in carbon dioxide can change the pH by as much as three units during the course of a sunny day — if the pond's alkalinity is low,” Higginbotham said. But with proper alkalinity levels, 20 parts per million or better, the fluctuations caused by oxygen release are buffered.
When is the right time to check a pond's water quality?
“Anytime is a good time,” Higginbotham said. “Don't wait until your fish are dying to call your county agent.”
Acid soils — and therefore acid water in ponds — are most common in Texas east of U.S. Interstate 45. Most Extension offices in counties east of I-35 should have water testing kits available. In local phone directories, Extension offices are usually listed under county offices/agriculture.
Farm ponds west of I-45 are not likely to have acidity problems.
There are an estimated one million farm ponds in Texas, the majority of which are in East Texas, representing an estimated half million surface acres, according to Higginbotham. For recreational value alone, these ponds are conservatively estimated to have a value of $125 per surface acre annually.
“In addition, properly managed ponds can produce 1,000 pounds of catfish per acre annually,” Higginbotham said.
The Renewable Resources Extension Act of 1978 strengthened existing Extension programs by mandating and funding an expanded role for Extension in renewable natural resource conservation and management. The Renewable Resources Extension Act (RREA) provides forest and rangeland owners and managers with information they need to produce wood products, forages and livestock, fish and wildlife populations and outdoor recreation opportunities in an environmentally friendly fashion.
The RREA, as with other Extension education programs, is conducted through the cooperative efforts of the Extension Service of the U.S. Department of Agriculture.