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ARS Home » Midwest Area » Bowling Green, Kentucky » Food Animal Environmental Systems Research » Research » Publications at this Location » Publication #308726
Title: Effect of turning frequency and season on composting materials from swine high-rise facilities

Author
item Cook, Kimberly - Kim
item RITCHEY, E - University Of Kentucky
item Loughrin, John
item Haley, Marty
item Sistani, Karamat
item Bolster, Carl

Submitted to: Waste Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/10/2015
Publication Date: 3/6/2015
Citation: Cook, K.L., Ritchey, E.L., Loughrin, J.H., Haley, M.A., Sistani, K.R., Bolster, C.H. 2015. Effect of turning frequency and season on composting materials from swine high-rise facilities. Waste Management. 39:86-95.

Interpretive Summary: Composting of swine manure has several advantages, liquid slurries are converted to solid, the total volume of material is reduced and the stabilized product is more easily transported off-site. Despite this, swine waste is generally stored, treated and applied in its liquid form. The high-rise finishing facility (HRFF) permits liquid slurries to be converted to solids which are partially decomposed underneath the HRFF and then finished in compost windrows. The purpose of this study was to evaluate the effect of turning frequency and weather conditions on biological, physical and chemical properties of composted swine-wood chip mixtures from HRFF. Compost trials were conducted in either fall (FT) or spring (ST) and piles were turned once, three times or upon reaching high temperatures. Physical, chemical and microbiological characteristics were measured over the course of 112 (FT) or 143 (ST) das of composting. Total carbon, total nitrogen (N) and inorganic N decreased in all piles. Ammonium decreased and nitrate increased in all piles (even unturned), but total N losses were greatest in piles turned more frequently during the ST. Microbial populations of nitrifiers were present in high concentrations, but populations varied in response to turning and compost temperature; denitrifiers that produce N gas or nitrous oxide were present in high concentrations throughout the process. Results suggest that it is feasible to finish swine HRFF materials in windrows regardless of season or turning regime. Volume reduction, low moisture and low readily degradable organic matter suggest that the finished compost would have lower transportation costs and should provide value as a soil conditioner.

Technical Abstract: Composting of swine manure has several advantages, liquid slurries are converted to solid, the total volume of material is reduced and the stabilized product is more easily transported off-site. Despite this, swine waste is generally stored, treated and applied in its liquid form. The high-rise finishing facility (HRFF) permits liquid slurries to be converted to solids which are partially decomposed underneath the HRFF and then finished in compost windrows. The purpose of this study was to evaluate the effect of turning regime and ambient weather conditions on biological, physical and chemical properties of composted swine-wood chip mixtures from HRFF. Compost trials were conducted in either fall (FT) or spring (ST) and piles were turned once, three times or upon reaching 65 ºC. Physical, chemical and microbiological characteristics were measured over the course of 112 (FT) or 143 (ST) das of composting. Total carbon, total nitrogen (N) and inorganic N decreased in all piles. Ammonium decreased and nitrate increased in all piles (even unturned), but total N losses were greatest in piles turned more frequently during the ST. Microbial populations of nitrifiers were dominated by ammonia-oxidizing archaea (3.0 X 103 to 4.2 X 106 cells g-1 compost) but ammonia oxidizing bacteria varied in response to turning and compost temperature (up to 6.0 X 105 cells g-1 compost); denitrifiers were present in high concentrations throughout the process. Results suggest that it is feasible to finish swine HRFF materials in windrows regardless of season or turning regime. Volume reduction, low moisture and low readily degradable organic matter suggest that the finished compost would have lower transportation costs and should provide value as a soil conditioner.