Comparisons of Exceptional Quality Biosolids Amendments As Disturbed Soil Amendments.

Exceptional Quality biosolids products are increasingly being used as amendments in urban landscapes. The objectives of this research were to compare various organic amendments developed from class A biosolids on chemical and physical properties of an amended soil and their beneficial effects on tall fescue and soybean employed as bioassay plants. The study was conducted in greenhouse pots. Two types of plants and six amendment treatments were factorially combined, replicated four times and arranged in a RCB design. The six treatments were: (i) synthetic fertilizer control; (ii) a mixture of 40% Blue Plains biosolids (BPB), 40% sawdust, and 20% sand; (iii) a mixture of 40% BPB, 30% sawdust, 25% sand, and 5% mineral "fines"; (iv) Tagro -  a standard biosolids blended material from Tacoma, WA (which is typically comprised of 40% Tacoma biosolids, 40% sawdust, and 20% sand); (v) a mixture of 40% Alexandria anaerobically digested biosolids 40% sawdust, and 20% sand; and (vi) biosolids compost. All treatments will be applied to the soil to meet the agronomic N needs of tall fescue (150 kg N/ha). Tall fescue (Festuca arundinacea) and soybean (Glycine max (L.) Merr.) were used as bioassay crops. A surface soil from Old Hickory deposit from Virginia was used as a container medium at a thickness of 15 cm. 200 tall fescue turfgrass seeds, and 80 soybean seeds were planted per pot. Following the application of seeding treatments, the pots were watered to 80% field capacity. The biosolids were analyzed for total solids, total organic C, total Kjeldahl N, C/N ratio, ammonium and nitrate N, P, K, trace elements, pH, electrical conductivity (EC), porosity, bulk density, water-holding capacity. Plant indicators of amendment quality measured were germination and emergence and plant biomass.