Environmental assessment of northern Colorado dairy systems: whole-farm predictions for past, future, and beneficial management practices
Date
2022
Authors
Loudenback, Andrea J., author
Dillon, Jasmine A., advisor
Archibeque, Shawn, committee member
Cramer, Catie, committee member
Mueller, Nathan, committee member
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Abstract
The Northern Great Plains region is projected to experience rising average daily temperatures, greater precipitation variability, and increased overall weather variability over the next 75 years. These changes have potentially negative implications for Colorado dairy systems. The objective of this study was to (1) evaluate implications of climate change on resource use and environmental footprints of Colorado dairies through the 21st century using the Integrated Farms Systems Model (IFSM) and (2) identify and evaluate Beneficial Management Practices (BMPs) to assess the Colorado dairy industry's ability to remain sustainable and productive through 2100. The Integrated Farm System Model (IFSM) was used to estimate the carbon (CF), blue water (WF), reactive nitrogen (RnF), and energy (EF) footprints of three dairy operations: 1100-head conventional (1100C), 1100-head organic (1100OR), and 2000-head conventional (2000C). The IFSM is a whole-farm, process-based model that simulates major biophysical processes, environmental impacts, and economics of beef, dairy, and crop farms over many years of weather. Model inputs were obtained from the literature, publicly available USDA databases, and expert input. Each farm was simulated over three time periods: historic (1990-2015), mid-century (2040-2065), and late century (2075-2100). Eight general climate models (GCMs) and two representative concentration pathway scenarios (RCP 4.5 and 8.5) were used to evaluate potential climate impacts to resource use and environmental footprints of the farms. After baseline footprints were obtained, BMPs were modeled to assess the impacts on each farm's environmental footprints over each time. BMPs included 1) covered manure basin on all three farms 2) covered manure basin with flare on the 1100C farm 3) spring and fall cycle calving and milking on the 1100OR and 4) decrease in dietary crude protein from the NRC recommendation of 16% to 14% and supplementation with amino acids on the 2000C farm. The results of this study indicate that BMPs have the potential to reduce environmental footprints on dairy farms in Colorado under future climate changes. On average, manure management BMPs reduced RnF and CFs over time by 11and 5%, respectively. Reducing CP to 14% reduced ammonia emissions on the 2000C farm by up to 10% over time, however, it resulted in an increase to total CF and WF, likely from changes in upstream processes from the baseline. Spring cycle milking and calving on the 1100OR farm reduced the WF, EF, and RnF over time by 6, 3, and 5% on average, respectively. Fall cycle milking and calving increased these footprints compared to the baseline and other BMPs. Both seasonal milking BMPs increased CFs. A significant finding of the study was that WFs were predicted to decrease over time on the 1100OR and 2000C farms, both of which were producing homegrown feed. Colorado is predicted to have significant water scarcity issues in the later part of the century, and these results show that the decrease in water availability will limit the dairy industries abilities to meet its production needs. Predicted footprint values for baseline and BMP scenarios were compared to studies that evaluated regional and national dairy production using IFSM, as well as life cycle assessment (LCA) findings that averaged US dairy production from many farms. Overall, this study predicts that BMPs can be effective in reducing environmental footprints of Colorado dairy farms, which may reduce the environmental impacts of the state's dairy industry. However, farms should be wary of one size fits all solutions and need to assess their goals, productivity needs, and feasibility before implementing changes to management practices.
Description
Rights Access
Subject
climate change
dairy
sustainability
Colorado
beneficial management practice
modeling