Production of the edible mushroom in the United States totaled 802 million pounds during the 2007–08 growing season, with 521 million pounds or 65% produced in Pennsylvania (Norris, 2009). The major ingredients in mushroom-growing substrate from farms in Pennsylvania are typically recycled agricultural waste products and other materials, which include hay, straw and horse bedding, poultry litter, corn cobs, corn stover, cottonseed meal, cocoa hulls, and gypsum in various amounts and proportions (Chang and Miles, 1989; Stamets, 2000). The ingredients are mixed, blended, and irrigated thoroughly, placed inside a production facility, and pasteurized with steam heat to sterilize the substrate before inoculation with mushroom spawn (Wuest, 1982). Sphagnum peatmoss is added later in the growing process (Beyer, 2003; Chang and Hayes, 1978).
After a cropping cycle has been completed and the substrate has been depleted of nutrients needed for growing mushrooms, the substrate is removed from the production facility and the discarded material is then referred to as fresh mushroom compost (Beyer, 2003; Chang and Hayes, 1978; Wuest, 1982). Before removal, however, the substrate is again pasteurized with steam heat to eliminate the potential for unwanted fungi and weed seeds (Wuest, 1982). Fresh mushroom compost was previously called spent mushroom substrate or mislabeled as “mushroom soil” (American Mushroom Institute, unpublished data). Although weathered or outdoor-aged mushroom compost has been used as an organic fertilizer and soil amendment for plant production in agriculture and horticulture (Chong et al., 1991b; Lohr et al., 1984a; Maher, 1991, 1994), limited information is available regarding the analysis of fresh mushroom compost (American Mushroom Institute, unpublished data). An estimated 650,000 to 700,000 yard3 of fresh mushroom compost are generated annually by the mushroom industry in Pennsylvania (American Mushroom Institute, unpublished data; Fidanza and Davis, 2009). The objective of this project was to analyze the fresh mushroom compost produced in southeastern Pennsylvania for chemical and physical properties considered important for plant growth and soil improvement.
Chong, C. & Rinker, D.L. 1994 Use of spent mushroom substrate for growing containerized woody ornamentals: An overview Compost Sci. Util. 2 45 53
Chong, C., Rinker, D.L. & Cline, R.A. 1991b A comparison of five spent mushroom composts for container culture of ornamental shrubs Mushroom Sci. 13 637 644
Chong, C., Cline, R.A. & Rinker, D.L. 1991a Growth and mineral nutrition status of containerized woody species in media amended with spent mushroom compost J. Amer. Soc. Hort. Sci. 116 242 247
Eaton, A.D., Clesceri, L.S., Rice, E.W., Greenberg, A.E. & Franson, M.H. 2005 Standard methods for the examination of water and wastewater 21st ed United Book Press Baltimore
Fidanza, M.A. & Davis, D.D. 2009 Recycled mushroom compost suppresses bird's nest fungi in landscape mulch J. Environ. Hort. 27 238 240
Landschoot, P.J. & McNitt, A.S. 2005 Using spent mushroom substrate (mushroom soil) as a soil amendment to improve turf Pennsylvania State Univ., Coop. Ext University Park
Lohr, V.I., O'Brien, R.G. & Coffey, D.L. 1984a Spent mushroom compost in soilless media and its effect on the yield and quality of transplants J. Amer. Soc. Hort. Sci. 109 693 697
Lohr, V.I., Wang, S.H. & Wolt, J.D. 1984b Physical and chemical characteristics of fresh and aged spent mushroom compost HortScience 19 681 683
Philippoussis, A., Zervakis, G.I., Diamantpoulou, P., Papadopoulou, K. & Ehaliotis, C. 2004 Use of spent mushroom compost as a substrate for plant growth and against plant infections caused by Phytophthora Mushroom Sci. 16 579 584
Rinker, D.L. 2002 Handling and using “spent” mushroom substrates around the world 43 60 Sanchez J.E., Royse D.J. & Hernandez G. Proc. 4th Intl. Conf. Mushroom Biol. Mushroom Products 20–23 Feb. 2002 Cuernavaca, México
Romaine, C.P. & Holcomb, E.J. 2001 Spent mushroom substrate: A novel multifunctional constituent of potting medium for plants Mushroom News 49 4 15
Stewart, D.P.C., Cameron, K.C. & Cornforth, I.S. 1998 Effects of spent mushroom substrate on soil chemical conditions and plant growth in an intensive horticultural system: A comparison with inorganic fertiliser Aust. J. Soil Res. 36 185 198
Swift, C.E. 2009 Sodium adsorption ratio (SAR) 12 Nov. 2009 <http://www.colostate.edu/Dept/CoopExt/TRA/PLANTS/sar>.
Wang, S.H.L., Lohr, V.I. & Coffey, D.L. 1984 Spent mushroom compost as a soil amendment for vegetables J. Amer. Soc. Hort. Sci. 109 698 702
Wuest, P.J., Fahy, H.K. & Fahy, J. 1995 Use of spent mushroom substrate (SMS) for corn (maize) production and its effect on surface water quality Compost Sci. Util. 3 46 50