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Spatially and Temporally Explicit Life Cycle Environmental Impacts of Soybean Production in the U.S. Midwest
journal contribution
posted on 2020-04-01, 12:53 authored by Xiaobo Xue Romeiko, Eun Kyung Lee, Yetunde Sorunmu, Xuesong ZhangUnderstanding spatially
and temporally explicit life cycle environmental
impacts is critical for designing sustainable supply chains for biofuel
and animal sectors. However, annual life cycle environmental impacts
of crop production at county scale across mutiple years are lacking.
To address this knowledge gap, this study used a combination of Environmental
Policy Integrated Climate and process-based life cycle assessment
models to quantify life cycle global warming (GWP), eutrophication
(EU) and acidification (AD) impacts of soybean production in nearly
1000 Midwest counties yr–1 over 9 years. Sequentially,
a machine learning approach was applied to identify the top influential
factors among soil, climate, and farming practices, which drive the
spatial and temporal heterogeneity of life cycle environmental impacts.
The results indicated that significant variations existed in life
cycle GWP, EU, and AD among counties and across years. Life cycle
GWP impacts ranged from −11.4 to 22.0 kg CO2-eq
kg soybean–1, whereas life cycle EU and AD impacts
varied by factors of 302 and 44, respectively. Nitrogen application
rates, temperature in March and soil texture were the top influencing
factors for life cycle GWP impacts. In contrast, soil organic content
and nitrogen application rate were the top influencing factors for
life cycle EU and AD impacts.