Brian C. Reeder

Earthen hatchery pond sediments may provide additional nutrients to the water column and act as a sink for nutrients and excess fertilizer. In 2008 and again in 2013 soil nutrient concentrations and phosphorus (P) adsorption were examined in five earthen ponds at Minor Clark Fish Hatchery, Kentucky. These ponds are annually filled with oligotrophic water from an upstream reservoir, fertilized, and drained during normal hatchery operations. Over time, pond nitrogen (N) and P additions have not kept up with soil losses. Soil extractable P concentrations decreased about an order of magnitude...

Although fertilization has been a common practice to increase fish production in low nutrient lakes and ponds, applicability of the practice in larger reservoirs is questionable. Under the assumption that increased algal production moves up the food web to fish, we fertilized Grayson Lake, Kentucky, surface water with high N to P ratio fertilizer during springs 1994 and 1995. April through July 1994 we added 1 kg P/ha and 22 kg N/ha over a 9-week period to approximately 162 ha of lake surface area. During 1995 we increased loading to 7 kg P/ha with 22 kg N/ha. Weekly photic zone water...