The RFS Reset: A Look at Corn Land Use and Conventional Ethanol Production

This report examines U.S. agricultural land use and crop production. It also examines how much additional corn and conventional ethanol could be produced if the historic trends for corn production and ethanol processing continue through 2022. This report uses the term “ethanol” to refer to conventional ethanol. The analysis allows the food and other non-ethanol portions of the corn crop to continue to grow in a manner that would not increase concerns about the availability of corn for the world’s food supply.

In many sources, including its Second Triennial Report to Congress, the U.S. Environmental Protection Agency (EPA) claims that biofuel growth driven by the renewable fuel standard (RFS) has resulted in increased U.S. agricultural land use. However, that is not the whole story. As can be seen in Figure ES-1, since about 2010 the crop acreage devoted to corn production has remained relatively constant while ethanol production has substantially increased. The land use increase determined by EPA appears to be dependent on the beginning and end points selected for the analysis. In addition, EPA’s Second Triennial Report looks at total biofuel land use, which combines both corn and soy. There is general agreement that soy land use has increased during the period since the RFS was implemented, but that does not mean that corn land use has also increased. Finally, EPA was unable to identify the corn land use increase specifically caused by the production of conventional ethanol under the RFS. EPA points out these errors and its inability to prove its contention in various parts of the report which are not highlighted or mentioned in its key findings. In fact, the conclusions that EPA reaches in the report are not fully supported by EPA’s own analysis or independent study of the data.

In its Second Triennial Report, EPA fails to recognize that U.S. farmers choose the allocation of their crop acres to different crops based on a wide variety of market drivers including weather, world crop supply balances, U.S. and world inventories, and imports and exports worldwide. The RFS has a slight influence on some of these variables, but it is not the large driver that EPA seems to imply. Since the U.S. is currently exporting corn and soy beans plus ethanol and distiller’s dried grains with solubles (DDGS) in amounts at or above pre-RFS levels, and imports of ethanol and biomass-based diesel (BBD) are currently minimal, there can be no indirect land use impacts from other countries for corn ethanol or BBD. Therefore, EPA’s claim of increased indirect land use impacts from other countries is unsupported.

Stillwater examined historic trends for U.S. farm acres planted in corn and harvested plus the volume of corn produced. While there is variability in the data, over the past 12 years, corn production has increased at an average rate of 2.3 bushels per acre per year. That rate closely aligns with the rate of growth maintained over the previous seven decades, and there continue to be new technologies introduced enabling this rate of growth to continue. Figure ES-2 demonstrates this historic growth in corn yields per acre.

This analysis has examined the continuation of these trends and found that from 2018 to 2022 an additional 1.7 billion bushels of corn can be produced on the same number of acres that was used in 2007. Assuming that non-ethanol demands for corn grow at the same rate as population, 0.3 billion additional bushels would be required annually to supply feed, seed, and non-ethanol industrial uses of ethanol (such as high fructose corn syrup, cationic starch and renewable chemicals feedstock). This would leave 1.4 billion bushels of new corn available for ethanol production, enough to achieve a production rate of 4.0 bgy of new ethanol in 2022.

Since this 4.0 bgy of new ethanol can be produced with no new farm land needed and while continuing to grow sufficient corn for food and other non-ethanol needs, there should be minimal concerns about additional indirect land use or new corn-for-food needs. It also appears that the nutrients needed for this new corn are fewer on a per-bushel basis than the nutrients required prior to 2000.