Influence of Corn Residue Harvest Management on Grain, Stover, and Energy Yields

Abstract

Economic, environmental, and energy independence issues are contributing to rising fossil fuel prices, petroleum supply concerns, and a growing interest in biomass feedstocks as renewable energy sources. Potential feedstocks include perennial grasses, timber, and annual grain crops with our focus being on corn (Zea mays L.) stover. A plot-scale study evaluating stover removal was initiated in 2008 on a South Carolina Coastal Plain Coxville/Rains-GoldsboroLynchburg soil association site. In addition to grain and stover yields, carbon balance, greenhouse gas (GHG) emissions and soil quality impact reported elsewhere in this issue, variation in gross energy distribution within various plant fractionswhole plant, below ear shank (bottom), above ear shank (top), cob, as well as leaves and stems of the bottom and top portions (n (part, year) =20) was measured with an isoperibol calorimeter. Stalks from above the ear shank were the most energy dense, averaging 18.8 MJ/kg db, and when combined with other plant parts from above the ear shank, the entire top half was more energy dense than the bottom half -18.4 versus 18.2 MJ/kg db. Gross energy content of the whole plant, including the cob, averaged 18.28±0.76 MJ/kg db. Over the 4 years, partial to total removal (i.e., 25 % to 100 %) of aboveground plant biomass could supply between 30 and 168 GJ/ha depending upon annual rainfall. At 168 GJ/ha, the quantity of corn stover biomass (whole plant) available in a 3,254-km 2 area (32 km radius) around the study site could potentially support a 500-MW power plant.

Dedicated Energy Crops and Crop Residues for Bioenergy Feedstocks in the Central and Eastern USA

“…Mourtzinis et al [69] showed that harvesting the above-ear corn plant fraction, while leaving the remaining stover in the field for soil erosion protection and soil organic matter maintenance, is a potential option for corn stover harvest in the Southeast. Other research concluded that harvesting the upper half of standing stover with cobs produced the highest quality feedstock and maintained soil productivity as determined by the soil management assessment framework (SMAF) [70,71]. Total precipitation and average air temperature during the growing season were strongly correlated with stover chemical composition, and the above ear portion of stover was more desirable due to lower lignin and higher cellulose content [72].…”

Residue Harvest Effects on Irrigated, No‐Till Corn Yield and Nitrogen Response

“…C orn crop residue harvest by chopping silage, baling stover,or grazing occurs on about 40% of Nebraska's 3,700,000 ha of corn land, primarily for feeding of beef (Klopfenstein et al, 2013) and may increase to meet future feedstock demands for ethanol production (Cantrell et al, 2014; Alternative Fuels Data Center, 2014; DuPont Cellulosic Ethanol. 2012; Biomass Research and Development Board, 2009).…”

Crop Residue Considerations for Sustainable Bioenergy Feedstock Supplies

“…Precipitation and temperature patterns were highly correlated with stover composition indicating that in addition to their effect on biomass yield, weather patterns may have multiple effects on potential biofuel production. Cantrell et al [16] provides a final insight regarding the use of corn stover for bioenergy by quantifying gross energy distribution within various plant fractions. Based on 4 years of research, they conclude that harvesting 25 to 100 % of the above-ground biomass could supply between 30 and 168 GJ ha −1 depending upon annual rainfall.…”