Abstract. A significant effort is currently underway to reduce farming inputs and their associated environmental impacts. These efforts use data-driven research techniques, such as life cycle assessment, which rely on up-to-date and situationally specific information. In cropping systems, tractor fuel use data is an important component for evaluating sustainability. The currently available tractor fuel consumption data may not be particularly accurate for sustainability analysis of cropping activities as it relies on engineering estimates or is more than 30 years old. As part of an on-farm energy use and sustainability project, tractor fuel consumption was monitored for four years on a western Minnesota research farm during the cultivation and harvest of corn, soybeans, oats, and alfalfa. We were interested in how our findings compared with published studies and the magnitude and reasons for potential differences. The results indicate that there was considerable variation in fuel use for the same field operations during the four years of observation at the site studied. The average fuel use in this study also showed some variation with published data. The variation was likely due to previously noted impacts of different soil types, equipment deployed, and tractor operations on fuel consumption. Accurate sustainability metrics are increasingly important as they are beginning to be used for developing regulations and policy for agriculture and agricultural products. The findings suggest that in order to ensure accuracy when analyzing cropping sustainability, fuel use data should be representative of the specific farming systems, equipment, and methods being examined. Keywords: Agricultural sustainability, Agronomy, Cropping systems, Life cycle assessment, Midwestern United States, Tractor fuel.
Comparative life cycle assessment of aquaponics and hydroponics in the Midwestern United States
