Dairy-CropSyst: Gaseous emissions and nutrient fate modeling tool

• Published in: Computers and electronics in agriculture 2019-07, Vol.162, p.962-978
• Main Authors: Khalil, Tariq M., Stöckle, Claudio O., Carlson, Bryan R., Uslar-Valle, Nicole, Nelson, Roger L., Frear, Craig S., Ma, Jingwei, Higgins, Stewart S., Leytem, April B., Dungan, Robert S.
• Format: Article
• Language: English
• Subjects: Ammonia; Anaerobic digestion; Computer simulation; Correlation coefficients; Dairy CAFOs; Dairy industry; Decision support systems; Emission; Environmental impact; Environmental management; Environmental protection; Farms; GHG emissions; Intensive farming; Irrigation; Manure management; Manures; Nitrous oxide; Nutrient management; Nutrients; Water resources; Whole-farm modeling
• ISSN: 0168-1699; 1872-7107
• DOI: 10.1016/j.compag.2019.05.039

•Dairy-CropSyst tracks nutrient and gaseous emission of dairy manure management.•Dairy-CropSyst simulates the effect of various manure treatments on farm emissions.•Dairy-CropSyst shows good results when compared to observed emissions.•The model can be used to streamline a farmer’s management of dairy manure.•Dairy-CropSyst can be used for emission reporting when calibrated properly. Dairy concentrated animal feeding operations (CAFO) are required to implement nutrient management plans enforced by environmental protection agencies to minimizing the risk of water resource degradation and to report gaseous emissions when they exceed certain threshold values. Although tools exist to aid in completing such tasks, few of the tools integrate the impact of on-farm manure treatment unit operations such as anaerobic digestion, solids separation, and nutrient recovery. Furthermore, existing tools do not estimate the nutrient value of recovered products and effluent leaving the dairy system or the nutrient fate after effluent is applied to crop fields. Dairy-CropSyst is a decision support tool for researchers and CAFO managers aimed at evaluating the effects of different manure treatment unit operations on gaseous emission and nutrient fate in dairy systems. The model tracks nutrients through the dairy system, including inorganic and organic forms of carbon, nitrogen, and phosphorus. This is accomplished by integrating established transformation and emission equations, performance parameters of manure treatments from industrial data and literature, and using a cropping system model for the land application evaluation. Comparison of simulated values with observed emissions indicated that model performance was reasonable. The overall correlation coefficient of observed and predicted ammonia and methane emission from dairy manure management was 0.72 and 0.58 respectively. Simulated and observed N2O emission were found in close agreement before and after the irrigation event, however, the model over estimated N2O emission after irrigation events (Coefficient of Residual Mass = −0.87). The use of Dairy-CropSyst has the potential to assist the dairy industry in decision making on manure management treatment strategies and as a tool for reporting GHG and ammonia emissions.