Life cycle assessment of spinach grown in an urban farm in Mansfield, Ohio.

Esha Shrestha
Staff Researcher
Ajay Shah
Food, Agricultural and Biological Engineering

More than 65% of the total spinach produced in the U.S. is produced in California (CA). Spinach produced in CA requires longer transportation distance (with refrigeration) to reach to consumers in Ohio. In recent years, with increasing number of vacant lots in many U.S. metropolitan areas, urban farming using high tunnel has been gaining more interest as food can be grown locally with minimal input. Thus, the objective of this study was to evaluate the greenhouse gases emissions (GHGe) of the spinach production in an urban farm in Mansfield, Ohio (OH) and compare with the conventional spinach production in CA for consumption in OH. This study was conducted in NECIC farm, which has 8 high tunnels (with total area of 17,280 sq. ft.) in 12 acres. Four different scenarios were considered for urban farming using 1) city water, 2) rainwater, 3) chemical fertilizer, and 4) compost. System boundary for the study included spinach production at the site and delivery to the market. The data used for the analysis were obtained from field visits, literature, and life cycle inventory database. GHGe associated with spinach production in the urban farm in high tunnel was 56-74% lower than the conventional farming. For conventional spinach farming, transportation contributed the most to the GHGe (0.39 kg CO2e/kg spinach), followed by irrigation and chemical fertilizer use (0.2 and 0.05 kg CO2e/kg spinach, respectively). Net GHGe for urban farming was in the range of 0.18-0.31 kg CO2e/kg spinach. Spinach farming in only 30% of the available vacant lots in Mansfield can produce around 1,080 metric ton of spinach annually, which is sufficient for Mansfield population, and will also generate $1 million in revenue. Spinach production at this scale can reduce the GHGe by 462 metric ton CO2e, equivalent to emissions from 1.85 million km driven by an average passenger vehicle.