Estimating Virtual Nitrogen Inputs to Integrated U.S. Corn Ethanol and Animal Food Systems
| Autor: | Christine Costello, Mikaela Algren, Amy E. Landis |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Corn ethanol
Animal food Nitrogen 010501 environmental sciences 01 natural sciences Zea mays Crop chemistry.chemical_compound Animal science Environmental Chemistry Animals Humans Ethanol fuel 0105 earth and related environmental sciences Ethanol Coproduct food and beverages General Chemistry Renewable fuels Animal Feed United States Diet chemistry Biofuel Biofuels Environmental science Cattle |
| Zdroj: | Environmental sciencetechnology. 55(12) |
| ISSN: | 1520-5851 |
| Popis: | To accurately assess contributions of human activities to nitrogen (N) cycle disruption, we must consider how systems such as food and renewable fuel production are connected. N impacts of food and biofuel systems have been studied separately, but links between them have not been sufficiently considered. Since 2002, corn ethanol production in the United States has increased sixfold, and ethanol coproducts' roles in animal diets have increased similarly. In this study, we estimated virtual N in ethanol fuel and animal products using the commodity-specific Net Anthropogenic Nitrogen Inputs (CSNANI) model, which uses national corn ethanol, crop, and animal production data to estimate animal diets and the corresponding virtual N inputs to agricultural commodities. Virtual N attributable to ethanol fuel was 30 to 35 g N per liter of ethanol. As ethanol coproduct inclusion in animal diets increased from 1997 to 2012, N per kilogram of beef protein decreased by 19% and N per kilogram of milk protein decreased by 13%. With allocation of virtual N between ethanol and ethanol feed coproducts, the virtual N of both ethanol fuel and products from animals consuming ethanol coproducts is reduced relative to estimates from studies that do not consider the connection between these systems. |
| Databáze: | OpenAIRE |
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