Using Biosolids for Turfgrass Sod Production.

Using Biosolids for Turfgrass Sod Production

Nicholas Bero, Shane Griffith, Doug Soldat, John Stier, Erik Ervin, Greg Evanylo, Derik Cataldi

Abstract

            Increasing urban populations have created the need for proper waste disposal services. Biosolids from sewage management systems have shown the potential to replace synthetic fertilizers in turfgrass systems, including sod production. Two companion studies were conducted to assess use of biosolids in sod production.  The studies were located in Remington,Virgina on a Ashburn-Dulles complex silt-loam and in Marshall, WI on a Dodge silt loam. Two biosolids products were used in each study. Remington biosolids were dewatered cake applied at 15, 30.5, and 46 wet Mg ha^-1 and dewatered cake blended with wood fines (ratio 1:0.65) applied at 17,34, and 51 wet Mg ha^-1 each providing 98, 196, and 294 kg PAN (plant available nitrogen) ha^-1 respectively. The final treatment was a split applied synthetic control at a total of 196 kg N ha^-1. Marshall biosolids were anaerobically digested cake applied at 11, 22, and 44 Mg ha^-1 providing 250, 500, and 1000 kg PAN ha^-1 and biosolids mixed with sand and sawdust (ratio 2:1:1) applied at 56, 84, and 112 Mg ha^-1 providing 250, 375, and 500 kg PAN ha^-1. The final treatment was a split applied synthetic control applied at a total of 309 kg N ha^-1. All treatments were incorporated to a depth of 5 cm after application. Remington used an 85% tall fescue (Festuca arundinacea Schreb. ‘Rebel Exeda’ ‘Rebel IV’ and ‘Justice’)/ 15% Kentucky bluegrass (Poa pratensis L. ‘Midnight’) mixture, by weight. Marshall grasses were a four-way blend of Kentucky bluegrass (Poa pratensis ‘Blue-Tastic’, ‘Midnight Star’, ‘Deepblue’, and ‘Blue Sapphire’.) Results from visual quality, color, sod tensile strength, and rooting strength indicate that a rate of 294 kg PAN ha^-1 in Reminton and 425 kg PAN ha^-1 in Marshall applied as cake was needed to produce equivalent sod to the synthetic fertilizer control. Data also show that decreasing rates of cake would be needed in subsequent years, where only 345 kg PAN ha^-1 would be needed in year two as N from remaining cake would be mineralized. Cake applied at 500 kg PAN ha^-1 in Marshall was also the most economically viable rate. Therefore results show biosolids applied at 1.5-1.8 times the rate of synthetic nitrogen is recommended in sod production in the first year, with the potential to reduce these inputs in following years.