Urban soils are typically degraded due to land disturbance. The poor quality physical and chemical properties of the soil can benefit from application of organic amendments. Local sources of such amendments are biosolids, which are treated domestic wastewater sludges. The objective of this experiment was to compare effects of various high quality biosolids-based soil amendments with synthetic fertilizer on the growth and quality of tall fescue (Schedonorus arundinaceus) under two different soil moisture regimes. The research site was a disturbed soil at the Virginia Tech Turfgrass Research Center in Blacksburg, Virginia. The experimental design was a split plot with irrigation regime as the main factor and soil amendments as the split factor. All treatments were arranged in four randomized complete blocks. The study was established in late summer 2013. Soil amendment treatments, applied prior to seeding in September 2013, were: 1) inorganic N, P, K applied according to soil test laboratory recommendations; 2) anaerobically digested, dewatered biosolids to supply agronomic N rate; 3) anaerobically digested, dewatered biosolids blended with sand and sawdust to supply agronomic N rate; 4) anaerobically digested, dewatered biosolids blended with sand and sawdust to supply agronomic P rate; and 5) composted biosolids to supply agronomic N rate. The agronomic N rate for the turfgrass was 224 kg of estimated plant available nitrogen (PAN) ha-1. Inorganic fertilizer was applied to supply annual P and K requirements prior to seeding in late summer, and the N was split into three application timings (September 2013, April 2014, and June 2014). Supplemental fertilizer N to achieve full agronomic N rate was applied to the treatment plots that received the agronomic P rate of blended biosolids-sand-sawdust. The area was seeded on September 13, 2013 with a tall fescue blend at a rate of 488 kg ha-1. Following full tall fescue establishment, in June 2014, two irrigation regimes, consisting of 0% and 80% evapotranspiration replacement every three days, were initiated. The study had three phases denoted as the pre-drought, drought, and recovery phases which started in April and concluded in August of 2014. Turfgrass color and quality, volumetric soil moisture percentage to a 5 cm depth, normalized difference vegetative index (NDVI), clipping yield, and turfgrass N uptake were measured bi-weekly throughout the growing season. During the first May through July 2014 irrigation season, results were that the fertilizer control consistently provided improved responses relative to the biosolids amended treatments. Clipping yield, quality, and NDVI were all significantly greater in the inorganic fertilizer treatment, but volumetric soil moisture percentages were slightly greater in the biosolids treatments. Turfgrass responses appeared to have been associated with plant available nitrogen, which was lower in the biosolids treatments than in the fertilizer treatment. Calculated PAN for the biosolids products was too low to achieve ideal turfgrass growth and quality. Improving the estimated PAN and/or splitting the organic amendment application times should improve the growth and quality of the turfgrass. / Master of Science

Composted biosolids have been shown to enhance turfgrass establishment and growth more than fertilizer alone, but few studies have investigated the production of turfgrass using uncomposted biosolids. Increasingly employed treatment methods that generate pathogen-free, low pollutant-containing biosolids are creating alternative products for use in urban settings.  Understanding the effects of these uncomposted and alternative biosolids products on turfgrass culture and soil chemical and physical properties is essential to understanding the benefits these products may provide in sod production systems. The objectives of this study were to compare processing methods, application and N mineralization rates of two biosolids products and an inorganic fertilizer control for sod fertilization on 1) agronomic parameters related to turfgrass quality, 2) the amount of soil, C and P exported at harvest, and 3) chemical and physical properties of the soil following sod harvest as an indicator of the benefits of biosolids use. The study was conducted on a sod farm in Remington, Virginia on a silt loam Ashburn-Dulles complex from 2009 to 2012. The biosolids products were applied at estimated plant available nitrogen (PAN) rates of 98 kg N ha-1  (0.5X), 196 kg N ha-1 (1.0X) and 294 kg N ha-1  (1.5X) for a tall fescue (Festuca arundinacea Schreb. \'Rebel Exeda\' \'Rebel IV\' and \'Justice\')/ Kentucky bluegrass (Poa pratensis L. \'Midnight\') mixture. One biosolids product was an anaerobically digested dewatered cake applied at 15, 30.5 and 46 wet Mg ha-1. The second biosolids product was the same cake blended with wood fines applied at 17, 34 and 51 wet Mg ha-1. The biosolids treatments were compared to an inorganic fertilizer control that supplied 196 kg N ha-1 through three applications over the production cycle. There were no differences in establishment between the cake biosolids treatments and the inorganic fertilizer control, but all of the blended biosolids were slower to establish. Only the 1.0X and 1.5X PAN rates from the cake biosolids matched the inorganic fertilizer control in producing an acceptable quality sod in ten months. Lower nitrogen uptake between the blended biosolids treatments compared to the inorganic fertilizer control and lower although acceptable sod quality ratings at harvest of the 1.0X cake biosolids indicate our PAN estimates of 30% organic nitrogen mineralization overestimated the PAN for both materials. There were no differences in sod tensile strength between the 1.5X cake biosolids and inorganic fertilizer control. There were no differences in transplant rooting strength among all treatments. After repeat applications of biosolids, the 0.5X rates did not increase soil extractable phosphorus, while the 1.0X rates steadily increased soil extractable phosphorus at. The 1.0X and 1.5X biosolids rates increased soil organic matter content, but only the 1.5X rate of cake biosolids reduced soil bulk density and mineral matter export at harvest. Overall results indicate that the cake biosolids are an acceptable fertility alternative to inorganic fertilizer, and applications of biosolids for sod production can improve soil quality. Sod growers should consider using biosolids in a rotational system to offset rising production costs and improve production field soil quality. / Master of Science

To achieve a sustainable use of energy we must increase our use of renewable energysources, biogas if one such source. One of the greatest potentials for biogas are in theagricultural sector and the Energy Agency calculates that 25% of the available manurecan be used for biogas production. The purpose of this thesis is to contribute withknowledge of co-digestion of manure and how this affects the methane potential andhow co-digestion affects the contents of NH4 in the sludge. The report includes a literature study to understand the digestion process and its partsand allows interpretation of data. The report includes analysis of data from HalmstadUniversitys experiment of anaerobic digestion and an additional digestion. The resultsobtained in this study shows that the effect of co-digestion varies depending on manure.Horse and chicken manure and beef and pig manure gives a positive effect to the codigestion.

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