|Rotz, Clarence - Al|
|RICHARD, TOM - Pennsylvania State University|
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 2/18/2016
Publication Date: 7/17/2016
Citation: Bonifacio, H.F., Rotz, C.A., Richard, T. 2016. Modeling of carbon and nitrogen gaseous emissions from cattle manure compost windrows. ASABE Annual International Meeting. P. 1.
Technical Abstract: Windrow composting of cattle manure is a significant source of gaseous emissions, which include ammonia (NH3) and the greenhouse gases (GHGs) of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). A manure compost model was developed to simulate carbon (C) and nitrogen (N) processes including mineralization, immobilization, and volatilization and their effects on and interactions with environmental conditions within the windrow. Comprehensive measurement data from a published independent cattle manure composting study were used in refining and assessing the model. Out of 15 measured parameters available for model evaluation, six were also used in refining model constants. Simulation results indicate that the model performed reasonably well in predicting environmental conditions (i.e., temperature and moisture), C and N balance within, and gaseous emissions from static (i.e., no turning) and turned windrows. At the end of 99 days of composting, predicted C (50%) and N (31%) losses for the static windrow were greater than the measured losses (45% and 19%, respectively). This discrepancy was not surprising as the NH3 biofiltration effect of the finished compost cover on the actual static windrow was not modeled. The model performed very well in simulating the turned windrow, with predicted C (78%) and N (55%) losses very close to measured losses (77% and 57%, respectively). The performance of the model was further assessed using another published independent dataset on a turned windrow, with predicted C (43%) and N (40%) losses comparable to measured losses (53% and 42%, respectively). The process-based compost model has been incorporated in a version of the Integrated Farm System Model (IFSM), a whole-farm simulation model used to evaluate the performance, environmental impacts, and economics of crop, dairy, and beef production systems. The new component enables whole farm evaluation of the impacts of implementing manure composting strategies along with other aspects of the farm.