corn

Quantifying lignin and carbohydrate composition of corn (Zea mays L.) is important to support the emerging cellulosic biofuels industry. Therefore, field studies with 0 or 100 % stover removal were established in Alabama and South Carolina as part of the Sun Grant Regional Partnership Corn Stover Project. In Alabama, cereal rye (Secale cereale L.) was also included as an additional experimental factor, serving as a winter cover crop. Plots were located on major soil types representative of their respective states: Compass and Decatur soils in Alabama and a Coxville/Rains-Goldsboro-Lynchburg soil association in South Carolina. Lignin and structural carbohydrate concentrations in the whole (above-ground) plant, cobs, vegetation excluding cobs above the primary ear (top), vegetation below the primary ear (bottom), and vegetation from above the primary ear including cobs (above-ear fraction) were determined using near-infrared spectroscopy (NIRS). The distribution of lignin, ash, and structural carbohydrates varied among plant fractions, but neither inclusion of a rye cover crop nor the stover harvest treatments consistently affected carbohydrate concentrations within locations. Total precipitation and average air temperature during the growing season were strongly correlated with stover composition indicating that weather conditions may have multiple effects on potential biofuel production (i.e., not only yield but also stover quality). When compared to the above-ear fractions, bottom plant partitions contained greater lignin concentrations. Holocellulose concentration was consistently greater in the above-ear fractions at all three locations. Data from this study suggests that the above-ear plant portions have the most desirable characteristics for cellulosic ethanol production via fermentation in the southeastern USA.

Many questions have surfaced regarding short-and long-term impacts of corn (Zea mays L.) residue removal for use in the biofuels industry. To address these concerns, a field study was established in eastern South Dakota in 2000 using no-till soil management within a 2-yr corn/soybean [Glycine max (L.) Merr.] rotation. The objective of this study was to examine the effects of three residue removal treatments of low (corn harvested for grain; all residues remain on soil surface), medium (corn harvested for grain; residue raked, baled, and removed), and high (aboveground corn biomass and grain removed) on soil quality, measured through particulate organic matter (POM), soil organic matter (SOM), wet aggregate stability (WAS), and dry aggregate size distribution (DASD). Following four complete rotational cycles, when residue was removed from the soil surface there was a consistent decrease in the amount of SOM and all fractions of POM regardless of aggregate size class, indicating a possible decrease in soil quality. This was further indicated by the near doubling of the erodible fraction in the high removal treatment compared to the low removal treatment. Potential further degradation of the soil structure is indicated by a shift in DASD among the residue removal treatments. Within this study, removal of corn residue had a negative impact on the soil physical and chemical properties measured, potentially illustrating the importance of crop residue to maintain our soil resource. Additional research is needed to incorporate other soil chemical and biological indicators before recommendations can be made.

The use of corn for ethanol production in the United States quintupled between 2001 and 2009, generating concerns that this could lead to the conversion of forests and grasslands around the blobe, known as indirect land-use change (iLUC). Estimates of iLUC and related "food versus fuel" concerns rest on the assumption that the corn used for ethanol production in the United States would come primarily from displacing corn exports and land previously used for other crops. A number of modeling efforts based on these assumptions have projected significant iLUC from the increases in the use of corn for ethanol production. The current study tests the veracity of these assumptions through a systematic decomposition analysis of the empirical data from 2001 to 2009. The logarithmic mean divisia index decomposition method (Type I) was used to estimate contributions of different factors to meeting the corn demand for ethanol production. Results show that about 79% of the change in corn used for ethanol production can be attributed to changes in the distribution of domestic corn consumption among different uses. Increases in the domestic consumption share of corn supply contributed only about 5%. The remaining contributions were 19% from added corn production, and -2% from stock changes. Yield change accounted for about two thirds of the contributions from production changes. Thus, the results of this study provide little support for large land-use changes or diversion of corn exports because of ethanol production in the United States furing the past decade.

This article addresses development of the Illinois ethanol industry through the period 2007-2022, responding to the ethanol production mandates of the Renewable Fuel Standard by the U.S. Environmental Protection Agency. The planning for corn-based and cellulosic ethanol production requires integrated decisions on transportation, plant location, and capacity. The objective is to minimize the total system costs for transportation and processing of biomass, transportation of ethanol from refineries to the blending terminals and demand destinations, capital investment in refineries, and by-product credits. A multi-year transshipment and facility location model is presented to determine the optimal size and time to build each plant in the system, the amount of raw material processed by individual plants, and the distribution of bioenergy crops and ethanol.

This paper examines the impact of biofuel expansion on grain utilization and distribution at the state and cropping district level as most of grain producers and handlers are directly influenced by the local changes. We conducted a survey to understand the utilization and flows of corn, ethanol and its co-products, such as dried distillers grains (DDG) in Iowa. Results suggest that the rapidly expanding ethanol industry has a significant impact on corn utilization in Iowa. Comparing to the earlier survey results, ethanol plants drew a considerable amount of corn away from traditional destination markets, such as feeders or export markets. A major portion of corn supplies came from in-state sources, while the sales of Iowa ethanol and DDG were dominated by out-of-state buyers.

A system of equations representing corn supply, feed demand, export demand, food, alcohol and industrial (FAI) demand, and corn price is estimated by three-stage least squares. A price dependent reduced form equation is then formed to investigate the effect of ethanol production on the national average corn price. The elasticity of corn price with respect to ethanol production is then obtained. Results suggest that ethanol production has a positive impact on the national corn price and that the demand from FAI has a greater impact on the corn price than other demand categories. Thus, significant growth in ethanol production is important in explaining corn price determination.

Events external to agriculture have set in motion the conditions for structural change in the marketing of corn in the U.S. These included a rapid increase in the price of crude oil from $40 per barrel to over $100 caused by hurricanes, geopolitical events, an increased global demand for energy from countries like China and India, and in December 2007, the U.S. raising the renewable fuel standards. The results of this research show that there could be significant changes in the historical utilization and marketing of corn in the U.S. The change in movement patterns provides one source of visible evidence that a structural change is underway.

This study focuses on the simulation of a complete process for producing butanol via
acetone, butanol, and ethanol corn fermentation.

This is an overview of transportation issues facing a rapidly expanding U.S. ethanol industry in the context of the U.S. corn market—currently the main source of ethanol production in the United States. The aim of the report is to present a frame of reference as the ethanol industry continues to grow and additional transportation benchmarks and indicators develop by providing analysis of transportation requirements for corn-based ethanol and its impact on grain transportation.

This paper summarizes some of the major impacts rapid growth in the corn
based ethanol (CE) production is now having on infrastructure in the Midwestern corn
producing states and examines some of the likely infrastructure needs that might be
expected to occur as a consequence of the future development of biomass based ethanol (BE) production