Control | Unamended native silt loam | 6.1–6.7 | n/a | n/a | n/a | n/a | n/a | n/a | n/a | Soil only |
Peat moss | Pro-Moss ‘Emerald’ Canadian sphagnum peat moss | 4.8 | n/a | n/a | n/a | 125 | n/a | n/a | Premier Horticulture, Quakertown, Pennsylvania, U.S. | Hand-mixed 1:4 volumetric ratio peat moss to native soil |
Leaf-based compost | Finely ground yard waste composted with poultry litter at 1:2 volumetric ratio for four months | 6.6 | 17 | 2,623 | 4.1 | 18 | 311 | 159 | Panorama Pay-Dirt, Earlysville, Virginia, U.S. | Hand-mixed 1:4 volumetric ratio compost to native soil |
Biosolids-based compost | Three-month-digested biosolids from a wastewater treatment plant combined with wood chips at 1:2 volumetric ratio. Composted 30 days, cured 4 months, and sieved to remove wood chips. | 6.7 | 15.9 | 2,181 | 9.0 | 17 | 265 | 76 | Wolf Creek Wastewater Treatment Plant, Abingdon, Virginia, U.S. | Hand-mixed 1:4 volumetric ratio compost to native soil |