Gypsum bedding impact on hydrogen sulfide release from dairy manure storages

Authors: HILE, MICHAEL - Pennsylvania State University; GABIAN-WHEELER, E - Pennsylvania State University; MURPHY, DENNIS - Pennsylvania State University; MEINEN, ROBERT - Pennsylvania State University; HILL, DAVIS - Pennsylvania State University; ELLIOT, HERSCHEL - Pennsylvania State University; Bryant, Ray

Submitted to: Biological Engineering (ASABE)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/1/2018
Publication Date: 6/1/2018
Citation: Hile, M.L., Gabian-Wheeler, E., Murphy, D.J., Meinen, R.J., Hill, D.A., Elliot, H.A., Bryant, R.B. 2018. Gypsum bedding impact on hydrogen sulfide release from dairy manure storages. Biological Engineering (ASABE). 61(3):937-941. https://doi.org/10.13031/trans.12463.
DOI: https://doi.org/10.13031/trans.12463

Interpretive Summary: Gypsum bedding is reported to control moisture and bacteria in the dairy stall and can improve soil structure when land applied. However, gypsum increases hydrogen sulfide production in the anaerobic environment of deep manure storages and is released when manure is stirred. Hydrogen sulfide is a toxic gas that can be fatal if inhaled in high concentrations. This study compared the hydrogen sulfide concentrations during stirring of manure storages from three dairy stall management systems: those that use (1) traditional organic bedding, (2) gypsum bedding and (3) gypsum bedding followed by adding a substance treatment to the manure storage thought to reduce hydrogen sulfide emissions. Results show that manure storage agitation at farms that use gypsum in bedding produced hydrogen sulfide concentrations that were considered immediately dangerous to life and health (above 100 ppm). Increasing gypsum bedding use significantly increased cumulative hydrogen sulfide concentrations. Hydrogen sulfide concentrations were significantly lower on farms that used gypsum bedding followed by additional treatments to the manure storage, compared to those not using a manure treatment.

Technical Abstract: Elevated hydrogen sulfide (H2S) levels have been observed from open-air dairy manure storages that contain gypsum bedding. Gypsum (calcium sulfate), recycled from construction waste and manufacturing defects, provides a cost-effective bedding alternative for dairy cows. Gypsum bedding is reported to control moisture and bacteria in the stall and can improve soil structure when land applied. However, gypsum increases H2S production in the anaerobic environment of deep manure storages, which is released in dangerous concentrations when manure is agitated. This study was undertaken to quantify and compare the H2S concentrations during agitation of manure storages from three dairy stall management categories: those that use (1) traditional organic bedding, (2) gypsum bedding and (3) gypsum bedding followed by a treatment added to the manure storage thought to reduce H2S emissions. Nineteen agitation events at ten farms were monitored during spring and fall hauling seasons. Portable monitoring instruments recorded H2S concentrations around the perimeter of manure storages prior to and during agitation. Results show that manure storage agitation at farms that use gypsum in bedding produced H2S concentrations that were considered immediately dangerous to life and health (above 100 ppm). Increasing gypsum bedding use significantly increased cumulative H2S concentrations (P-value <0.0001). Farms that used VitalTM Breakdown as an amendment significantly reduced cumulative H2S concentrations when compared to farms not using a manure amendment (P-value<0.0001). Lower cumulative H2S concentrations at one farm were also attributed to the manure amendment OK-1000.