Analysis of Fresh Mushroom Compost - …

1 Analysis of Fresh Mushroom CompostMichael A. Fidanza1,3, David L. Sanford1, David M. Beyer2,and David J. Aurentz1 ADDITIONAL INDEX WORDS. carbon, nitrogen, organic matter, phosphorus,potassium, soluble saltsSUMMARY. Fresh Mushroom Compost is a byproduct of the edible Mushroom (Agaricus bisporus) industry and represents the composted growing substrate thatremains after acrop has been harvested tocompletion. Thirty samples were obtainedfrom commercial Mushroom farms in southeastern Pennsylvania and sent toa laboratory for Analysis to determine plant nutrient content, bulk density, andparticle size distribution of Fresh Mushroom Compost . Fresh Mushroom composthad an average pH of , with an average carbon:nitrogen ratio of 13:1. Organicmatter content averaged (wet weight), lb/yard3(wet volume) (dry weight). For the primary macronutrients, average total nitrogencontent averaged (wet weight), lb/yard3(wet volume) or (dryweight), phosphorus measured (wet weight), lb/yard3 (wet volume) (dry weight), and potassium was (wet weight), lb/yard3(wetvolume) or (dry weight).

2 Average soluble salt content was mmho/cm(wet weight basis). However, on a per acre basis, the calculated sodium absorptionratio of was considered very low. The average bulk density of Fresh mushroomcompost was lb/yard3(wet volume basis), and 91% of the material measured 3/8 inch in diameter as determined on a wet weight basis. Overall, freshmushroom Compost is suitable as a natural organic fertilizer and soil amendmentfor agriculture and of the edible mush-room in the United States to-taled 802 million pounds duringthe 2007 08 growing season, with 521million pounds or 65% produced inPennsylvania (Norris, 2009). The ma-jor ingredients in Mushroom -growingsubstrate from farms in Pennsylvaniaare typically recycled agricultural wasteproducts and other materials, whichinclude hay, straw and horse bedding,poultry litter, corn cobs, corn stover,cottonseed meal, cocoa hulls, andgypsum in various amounts and pro-portions (Chang and Miles, 1989;Stamets, 2000).

3 The ingredients aremixed, blended, and irrigated thor-oughly, placed inside a production fa-cility, and pasteurized with steam heatto sterilize the substrate before inocu-lation with Mushroom spawn (Wuest,1982). Sphagnum peatmoss is addedlater in the growing process (Beyer,2003; Chang and Hayes, 1978).After a cropping cycle has beencompleted and the substrate has beendepleted of nutrients needed forgrowing mushrooms , the substrateis removed from the production facil-ity and the discarded material is thenreferred to as Fresh Mushroom com-post (Beyer, 2003; Chang and Hayes,1978; Wuest, 1982). Before removal,however, the substrate is again pas-teurized with steam heat to eliminatethe potential for unwanted fungiand weed seeds (Wuest, 1982). Freshmushroom Compost was previouslycalled spent Mushroom substrateor mislabeled as Mushroom soil (American Mushroom Institute, un-published data). Although weatheredor outdoor-aged Mushroom composthas been used as an organic fertilizerand soil amendment for plant pro-duction in agriculture and horticul-ture (Chong et al.)

4 , 1991b; Lohr et al.,1984a; Maher, 1991, 1994), limitedinformation is available regardingthe Analysis of Fresh Mushroom com-post (American Mushroom Institute,unpublished data). An estimated650,000 to 700,000 yard3of freshmushroom Compost are generatedannually by the Mushroom industryin Pennsylvania (American Mush-room Institute, unpublished data;Fidanza and Davis, 2009). The ob-jective of this project was to analyzethe Fresh Mushroom Compost pro-duced in southeastern Pennsylvaniafor chemical and physical propertiesconsidered important for plant growthand soil and methodsDuring late Winter/early Spring2005, 30 Fresh Mushroom compostsamples were collected from mushroomfarms in southeastern Pennsylvania,particularly the Mushroom -growing re-gions in Berks and Chester samples were acquired as the ma-terial was being removed from a pro-duction facility, and were not allowed tostockpile or age outdoors.

5 Each samplewas placed in a 1-gal plastic containerand was securely shipped to the Agri-cultural Analytical Services Laboratory(Pennsylvania StateUniversity, Univer-sity Park) for processing and tests measured the follow-ing properties: pH, carbon:nitrogen(C:N) ratio, soluble salts, solids, mois-ture, organic matter, carbon, totalnitrogen (N), organic nitrogen, ammo-nium nitrogen, phosphate (P2O5), pot-ash (K2O), calcium (Ca), magnesium(Mg), sulfur (S), sodium (Na), alumi-num (Al), iron (Fe), manganese (Mn),copper (Cu), and zinc (Zn). Althoughlaboratory results reported P2O5andK2O values, actual phosphorus (P) andUnitsTo convert to SI,multiply unitSI unitTo convert SI to ,multiply (s) (es) ha m m ha ha support for this project was provided by theMushroom Industry Farmer-Based Applied ResearchProgram, administered through the American Mush-room Institute (Washington, DC), and by the HonorableEdward G.

6 Rendell, Governor of the Commonwealthof Pennsylvania, administered through the ChesterCounty Economic Development Council, Project (Exton, PA).1 Pennsylvania State University, Berks Campus, Di-vision of Science, 111 Luerssen Building, Reading,PA 196102 Pennsylvania State University, Department of PlantPathology, Buckhout Laboratory, University Park,PA 168023 Corresponding author. E-mail: April 2010 20(2)449potassium (K) were calculated fromP2O5and K2O, respectively (Bradyand Weil, 1996). Two additional labo-ratory tests measured bulk density andparticle size distribution. Laboratorytest methods and procedures are basedon the Test Methods for Evaluation ofCompost and Composting program asrecommended by the CompostingCouncil (West Conshohocken, PA)and the American Society of TestingMaterials (Rokonkoma, NY), and alsobased on analytical methods describedin Eaton et al. (2005). A detailed list ofthe analytical methods used for eachtest can be obtained through Agricul-tural Analytical Services Laboratory.

7 Ofinterest for growth media in horticul-ture, soluble salt content was measuredindirectly from electrical conductivity(EC) using a 1:5 ( Compost :water) slurry(Agricultural Analytical Services Labo-ratory, unpublished data).The laboratory tests determinedcompost characteristics on a wet weight,wet volume, and dry weight basis. Bulkdensity was determined as is ( , asreceived at the laboratory, and notoven-dried) on a wet volume basis [testmethod TMECC , Com-posting Council (Westerman, 1990)]and particle size also was determined asis on a wet weight basis. Data from allsamples were compiled to determinemean, standard deviation, and the min-imum and maximum values (Steeland Torrie, 1980) for each parameter(Statistix, version 9; Analytical Software,Tallahassee, FL). Also, wet volume lab-oratory results data were used to calcu-late the amount of plant nutrients infresh Mushroom Compost per acre,as well as the sodium adsorption ratio(SAR) per acre (Swift, 2009).

8 The SAR,calculated as follows,SAR = Na+ ffiffiffiffiffiffiffiffiffiffiffiffiffif fiffiffiffiffiffiffiffiffiffiffiffi Ca2+ + Mg2+ 2qcompares Na concentration relativeto the concentrations of Ca and Mg(Brady and Weil, 1996).Results and mush-room Compost had an average pH (Table 1) within the optimum soilpH range of to for growingmost agricultural and horticulturalcrops (Acquaah, 2009; Foth, 1984).Lohr et al. (1984b) reported an aver-age leachate pH of for freshmushroom Compost . Only threesamples were used in that study froma single Mushroom farm in Tennessee(Lohr et al., 1984b) compared with30 samples from multiple farms in thisinvestigation, and the amount andquality of materials used to make mush-room substrate is dramatically differentin Pennsylvania (Beyer, 2003; Wuest,1982; Wuest et al., 1995). The C:Nratio of Fresh Mushroom Compost inthis study averaged 13:1 (Table 1),within the desired range of 10:1 to15:1 for ideal Compost (Stoffella andKahn, 2001).

9 SOLUBLE average ECof Fresh Mushroom Compost was (Table 1), which is notconsidered high enough to damageturfgrass (Landschoot and McNitt,2005) or impede plant production(Wang et al., 1984). In addition, saltconcentrations can be significantly di-luted when a Compost is incorporatedor tilled into a soil or soil amendment(Stoffella and Kahn, 2001). Lohr et al.(1984b) reported an EC of 22 mmho/cm for Fresh Mushroom Compost , andconcluded that K, Ca, and Mg con-centrations accounted for 80% to 90%of total dissolved salts present in satu-rated paste extracts used to measureEC in that study. However, it is diffi-cult to compare soluble salt concentra-tion in Compost from previous researchwhen different analytical methods areused (Carter, 1993). Although solublesalt concentration of Compost is oftena concern to practitioners (Tyler,1996), this material has been usedsuccessfully in many plant productionsystems (Chong and Rinker, 1994;Chong et al.)

10 , 1991a; Philippoussiset al., 2004; Romaine and Holcomb,2001; Wang et al., 1984; Wuest et al.,1995).BULK DENSITY,SOLIDS, bulk density (Table2) averaged lb/yard3(wetvolume), with over half of the weightattributed to water. Lohr et al. (1984b)reported an average bulk density lb/yard3for Fresh mushroomcompost, and again, this lower valuereflects a difference in the amountand quality of materials used to makemushroom substrate today in Pennsyl-vania (Beyer, 2003; Chang and Hayes,1978; Wuest, 1982; Wuest and Fahy,1992; Wuest et al., 1995). In thisstudy, Fresh Mushroom Compost con-tained an average amount of solidsat (wet weight) or 1. Analysis of Fresh Mushroom Compost on a wet weight measuredzMeanSDRangeMinimum :nitrogen salts (mmho/cm) % nitrogen (NH4-N) < < < < < < < < Mushroom Compost samples (n= 30) were collected in 1-gal ( L) containers and analyzed by theAgricultural Analytical Services Laboratory (Pennsylvania State University, University Park) from Jan.