Intensifying the Corn-Soybean Rotation with the Use of Winter Rye Grown for Biomass Energy Production in Eastern South Dakota.

Among cereal crops, winter rye (Secale cereale L.) is known for its superior ability to overwinter and produce rapid regrowth in the spring. As a result, it is often the crop of choice for early-season ground cover and biomass production. This study evaluated winter rye biomass reproduction and estimated ethanol yield from rye grown after corn and before soybeans (i.e. soybeans were planted on rye stubble after the rye was taken off as a biomass crop at heading). The management variables evaluated were: i) growing winter rye after corn under varying times of corn maturity to allow for earlier planting of rye; and ii) broadcast seeding of rye at early dent stage (R4) versus direct seeding following grain harvest. Rye biomass yield was determined at heading and cellulosic ethanol yield was estimated. Agronomic field trials conducted in Eastern South Dakota (SD) between the 2011 and 2014 growing seasons showed that planting early-season corn lines in order to advance rye planting date cannot be justified due to significant decrease in corn yield without much benefit in rye biomass in the spring. The broadcast seeded rye consistently produced 10%-35% less biomass in the spring when compared to drill seeded. Overall average rye biomass yield was 3030 lb per acre and average estimated ethanol yield was 139 gal per acre in this study. The results from the study showed potential of winter rye to be a strong cover or bioenergy crop when incorporated into corn-soybean system.