Winter composting of separated pig slurry solids and greenhouse gas emissions
One strategy to manage pig slurry is centrifugation and composting of the solids fraction to produce a value added product to distribute manure nutrients further from productions sites. This study determined turned windrow composting was suitable for processing slurry solids throughout winter. It was also the first attempt at combining automated chambers and a Fourier Transform Infrared spectroscopy analyzer to measure multiple gases during the composting process; the system proved capable but captured fluxes better if conducted in an area sheltered from wind. Straw and woodshavings were shown suitable as bulking materials for composting slurry solids, however, the lack of porosity provided by woodshavings created anaerobic conditions that doubled the greenhouse gas emissions compared to those of straw, 1,126 kg CO2-equivalent Mg-1 compared to 526 kg CO2-equivalent Mg-1. Either bulking material produced compost of quality for use in agricultural or soil blending applications and was free of manure pathogens.