Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016
After decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other import...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/abecbe |
| _version_ | 1797747704610160640 |
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| author | Xuesong Zhang Tyler J Lark Christopher M Clark Yongping Yuan Stephen D LeDuc |
| author_facet | Xuesong Zhang Tyler J Lark Christopher M Clark Yongping Yuan Stephen D LeDuc |
| author_sort | Xuesong Zhang |
| collection | DOAJ |
| description | After decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other important environmental indicators, such as soil erosion and nutrient loss, remain largely unquantified. Here, we simulated the environmental impacts from the conversion of grassland to corn and soybeans for 12 US Midwestern states using the EPIC (Environmental Policy Integrated Climate) model. Between 2008 and 2016, over 2 Mha of grassland were converted to crop production in these states, with much less cropland concomitantly abandoned or retired from production. The net grassland-cropland conversion increased annual soil erosion by 7.9%, nitrogen (N) loss by 3.7%, and soil organic carbon loss by 5.6% relative to that of existing cropland, despite an associated increase in cropland area of only 2.5%. Notably, the above estimates represent the scenario of converting unmanaged grassland to tilled corn and soybeans, and impacts varied depending upon crop type and tillage regime. Corn and soybeans are dominant biofuel feedstocks, yet the grassland conversion and subsequent environmental impacts simulated in this study are likely not attributable solely to biofuel-driven land use change since other factors also contribute to corn and soybean prices and land use decisions. Nevertheless, our results suggest grassland conversion in the Upper Midwest has resulted in substantial degradation of soil quality, with implications for air and water quality as well. Additional conservation measures are likely necessary to counterbalance the impacts, particularly in areas with high rates of grassland conversion (e.g. the Dakotas, southern Iowa). |
| first_indexed | 2024-03-12T15:54:27Z |
| format | Article |
| id | doaj.art-1f2856e97fd04ba68a7c7450ac7478aa |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:54:27Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-1f2856e97fd04ba68a7c7450ac7478aa2023-08-09T14:57:50ZengIOP PublishingEnvironmental Research Letters1748-93262021-01-0116505401810.1088/1748-9326/abecbeGrassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016Xuesong Zhang0https://orcid.org/0000-0003-4711-7751Tyler J Lark1https://orcid.org/0000-0002-4583-6878Christopher M Clark2https://orcid.org/0000-0003-3475-9886Yongping Yuan3https://orcid.org/0000-0002-6843-3342Stephen D LeDuc4https://orcid.org/0000-0003-2908-0000Earth System Science Interdisciplinary Center, University of Maryland , 5825 University Research Ct, College Park, MD 20740, United States of AmericaCenter for Sustainability and the Global Environment, University of Wisconsin-Madison , Madison, WI 53726, United States of America; DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison , Madison, WI 53726, United States of AmericaUS Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment , Washington, DC, United States of AmericaUS Environmental Protection Agency, Office of Research and Development, Center for Environmental Measurement and Modeling , Research Triangle Park, NC, United States of AmericaUS Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment , Research Triangle Park, NC, United States of AmericaAfter decades of declining cropland area, the United States (US) experienced a reversal in land use/land cover change in recent years, with substantial grassland conversion to cropland in the US Midwest. Although previous studies estimated soil carbon (C) loss due to cropland expansion, other important environmental indicators, such as soil erosion and nutrient loss, remain largely unquantified. Here, we simulated the environmental impacts from the conversion of grassland to corn and soybeans for 12 US Midwestern states using the EPIC (Environmental Policy Integrated Climate) model. Between 2008 and 2016, over 2 Mha of grassland were converted to crop production in these states, with much less cropland concomitantly abandoned or retired from production. The net grassland-cropland conversion increased annual soil erosion by 7.9%, nitrogen (N) loss by 3.7%, and soil organic carbon loss by 5.6% relative to that of existing cropland, despite an associated increase in cropland area of only 2.5%. Notably, the above estimates represent the scenario of converting unmanaged grassland to tilled corn and soybeans, and impacts varied depending upon crop type and tillage regime. Corn and soybeans are dominant biofuel feedstocks, yet the grassland conversion and subsequent environmental impacts simulated in this study are likely not attributable solely to biofuel-driven land use change since other factors also contribute to corn and soybean prices and land use decisions. Nevertheless, our results suggest grassland conversion in the Upper Midwest has resulted in substantial degradation of soil quality, with implications for air and water quality as well. Additional conservation measures are likely necessary to counterbalance the impacts, particularly in areas with high rates of grassland conversion (e.g. the Dakotas, southern Iowa).https://doi.org/10.1088/1748-9326/abecbeagriculturebiofuelland useenvironmental impactserosionnitrogen |
| spellingShingle | Xuesong Zhang Tyler J Lark Christopher M Clark Yongping Yuan Stephen D LeDuc Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 Environmental Research Letters agriculture biofuel land use environmental impacts erosion nitrogen |
| title | Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 |
| title_full | Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 |
| title_fullStr | Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 |
| title_full_unstemmed | Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 |
| title_short | Grassland-to-cropland conversion increased soil, nutrient, and carbon losses in the US Midwest between 2008 and 2016 |
| title_sort | grassland to cropland conversion increased soil nutrient and carbon losses in the us midwest between 2008 and 2016 |
| topic | agriculture biofuel land use environmental impacts erosion nitrogen |
| url | https://doi.org/10.1088/1748-9326/abecbe |
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