Biosolids Effects On Soil Properties in Tall Fescue Sod Production.

The amount of biosolids created by municipal wastewater facilities continues to grow each year, while close proximity land that is suitable for biosolids application is increasingly difficult to find.  Using biosolids to supply turfgrass nutrients for sod production can help alleviate this issue. The purpose of this study is to compare the effects of biosolids treatments to synthetic fertilizer sod production.  Two biosolids products from the Alexandria Sanitation Authority, a class A dewatered cake and the same material blended with wood fines, were applied at three rates designed to supply 0.5x, 1.0x and 1.5x the agronomic nitrogen rate (196 kg N/ha^-1) and compared to a synthetic fertilizer control treatment (196 kg N/ha^-1) .  Plots (61 m by 10.5 m) were established fall of 2009 and 2010 in a Kentucky bluegrass (Poa pratensis) and tall fescue (Festuca arundinacea) mixture on a sod farm in Remington, Virginia.  Soil export at harvest, extractable phosphorus, bulk density, and organic matter (OM) accumulation were measured at the end of each growing season in 2010-11.  We removed an average of 174.55 Mg of mineral soil ha^-1 with each 2.2 cm harvest depth with no biosolids. The dewatered cake biosolids treatments did not and the 1.5x rate of the blended product did increase soil P concentration both years.  Bulk density was not different between treatments after two years of biosolids applications.  Soil OM increased with the highest biosolids rates,  and OM in all biosolids treatments were higher than the control.  Biosolids application resulted in improved soil quality in the sod production field relative to standard.