Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 11, 2011
Publication Date: December 14, 2011
Citation: Rocateli, A.C., Raper, R.L., Balkcom, K.S., Arriaga, F.J., Bransby, D.I. 2011. Biomass sorghum production and components under different irrigation/tillage systems for the southeastern U.S. Industrial Crops and Products. 36:589-598. Interpretive Summary: Successful production of large biomass crops in the southeastern US will be required to produce large amounts of biofuels. Annual crops such as biomass sorghum, could fit within existing annual crop production systems without excessively disrupting current markets. Research must be conducted to develop methods of production that don’t require excessive amounts of tillage or irrigation. This experiment compares several varieties of biomass sorghum against a grain sorghum and a widely-produced variety of corn for overall biomass production and also components that could be converted to biofuel. Results indicated that photoperiod-sensitive variety of sorghum produced the maximum biomass over the entire growing season, but if a shorter season was desired, a forage sorghum could be used and harvested in a much quicker time frame. These results should enable producers and biorefineries to make decisions about production practices, as well as, potential yields of biomass and biofuels using these crops.
Technical Abstract: Seeking renewable energy sources is necessary to reduce the US dependence on foreign oil. Sorghum (Sorghum bicolor L.) may be a reasonable alternative as an energy crop in the Southern U.S. because it is drought resistant. An experiment was developed to evaluate several types of sorghum as bioenergy crops in Alabama. The types of sorghum evaluated were: grain sorghum – NK300 (GS), forage sorghum – SS 506 (FS), and photoperiod sensitive forage sorghum - 1990 (PS). These sorghum crops and a forage corn (Zea mays L.) – Pioneer 31G65 were grown in 2008 and 2009 under irrigated and non-irrigated treatments, and under conventional (total disked area, 0.15 m deep) and conservation tillage (in-row subsoiling, 0.30 m deep) which resulted in a strip-split-plot design. The parameters evaluated were: plant population (PP), plant height (PH), sorghum/corn aboveground dry matter (ADM), biomass moisture content (ABMC), and biomass quality (holocellulose, lignin, and ash). Results showed that all sorghum crops had higher ADM production than corn; however, corn had lower ABMC than all sorghum crops. Lodging was observed in PS and FS plots, probably due to high plant populations (> 370,000 plants ha-1). Irrigation affected ADM positively in both years, but conservation system improved ADM production only in 2009. Holocellulose, lignin, and ash content differences among crops were lower than 8.3%, 2.0% and 1.9 %, respectively, for both years and considered minor. PS was considered the best variety for ADM production which produced 26.04 and 30.13 Mg ha-1 at 18 and 24 weeks after planting (WAP).