NUTRIENTS IN A PLAYA WETLAND RECEIVING WASTE-WATER

We determined nutrient sequestration differences in soil and vegetatio n within two regions of a playa wetland that receives agricultural run off and secondarily treated wastewater, Playas are small, topographica lly closed, ephemeral wetlands that serve as catchments for surface ru noff in the Southern High Plains of the USA, The wetland studied recei ved natural runoff and secondarily treated wastewater from the U.S. De partment of Energy, Pantex facility near Amarillo, TX, Soil and aboveg round biomass N, P, Cu, and Fe and water N and P were evaluated seven times during a 2-yr period in cattail (Typha domingensis Pers.) and pi nk smartweed [Persicaria pensylvanica (Raf,) Nieuw.] dominated regions of the playa, Spatial and temporal variabilities were observed in wat er, vegetation, and soil-nutrient concentrations, These variabilities were likely due to fluctuation of water depth and quality in the playa . Water was deeper (P < 0.05) in the cattail region compared with tile smartweed region, Water quality [Total Kjeldahl N (TKN) and total P ( TP)I was not effected (P > 0.05) by vegetation type. Soil concentratio ns of TKN, TP, Cu, and Fe were not significantly different (P > 0.05) between cattail and smartweed vegetative types. Cattail had significan tly greater (P < 0.05) levels of TKN, TP, Cu, and Fe than did smartwee d. Aboveground biomass was greatest in August. Based on nutrient seque stration this playa wetland functioned quite well as a receptor for ad ded nutrients from runoff and the wastewater treatment facility.