Check Your Waste Lagoon
Many farmers who are watching how this spring's excessive rains are affecting their crops would be well advised to check the banks of their livestock waste lagoons too.
"Manure lagoons may be filling up at a time when fields are too busy or too wet to land-apply effluent," says Don Jones, Purdue Extension specialist in livestock waste systems. "Routine lagoon maintenance and management are essential to secure timely and safe application of lagoon water on cropland."
Jones suggests the following lagoon management guidelines:
* Put a water-level gauge in the lagoon and monitor it routinely. The gauge will help you plan ahead for land application. If the water level drops quickly, look for seepage. Be vigilant during heavy rains.
"Any overflow from lagoons is strictly prohibited in Indiana, but a much more serious problem would be damage to the earthen dam that could cause a large amount of contaminated water to drain from the lagoon in a very short period of time," Jones says.
He advises farmers to keep good grass cover on sides of lagoon berms to stabilize their banks. "Keep weeds and floating debris out of the lagoon to control mosquitoes and make inspection easier," he adds. "Use gravel rip-rap near the water line to control erosion and weeds."
Jones also says farmers should maintain proper dilution to encourage wastewater treatment and reduce odors. "A good rule of thumb in Indiana is one part clean water for each part manure, by volume," he says. Add relatively small amounts of manure fairly often. Start lagoons with plenty of dilution water, preferably in the spring or early summer, to establish a large supply of organisms to break down organic matter without causing serious odor problems.
"If irrigating on growing crops, reduce the application volume based upon infiltration rate of the soils. Do not apply during hot, still days and apply early in the morning. If possible, wash off the plants with clean water after the application," Jones says.
Purdue publication ID-120, available through Extension offices, provides information on design and management of Indiana lagoons.