Can forage sorghum types be grown as feedstock for bioenergy in northern latitudes?

Authors: BERTI, MARISOL - North Dakota State University; Anderson, James; SAMARAPPULI, DULAN - North Dakota State University; CECCHIN, ANDREA - North Dakota State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 8/5/2021
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Forage sorghum [Sorghum bicolor (L.) Moench.] cultivars and hybrids have been selected for forage yield and nutritive value, for many years. Forage sorghum is used primarily for silage and grazing. Generally, farmers use a single-cut strategy that results in the highest biomass yield at the lowest cost. In addition, currently private industry and institutes are breeding forage sorghum and sorghum-sudangrass hybrids for northern climates. Some of these new cultivars are photoperiod sensitive, which can increase biomass productivity due to the longer vegetative stage. The objective of this study was to determine the biomass yield potential of forage sorghum cultivars and hybrids grown in northern latitudes of North America and its correlation with accumulated growing degree-days (GDDs). For this study, forage sorghum yield trial data from several US states and Canadian Provinces (above the 40-degree latitude) was compiled and correlated with accumulated (GDDs). In addition, forage sorghum yield data from European countries in latitudes above 40-degrees was obtained from available literature. The data was used to conduct a meta-analysis for determining the locations were high yielding forage sorghum cultivars and hybrids have potential to be grown as feedstocks for biofuels. In the northern Great Plains, dry matter yield of biomass sorghum in trials (2009 to 2019) ranged from 8 to 30 Mg ha-1 year-1, depending on cultivar and GDDs accumulated during each growing season. In the northern Great Plains, the mean dry matter yield averaged across all locations and cultivars tested was 13 Mg ha-1. However, with many cultivars yielding above the mean in most years, there is great potential for improving dry matter yield. In Europe, Germany, and many eastern European countries sorghum is increasingly being grown as a feedstock for biogas production to replace the use of maize (Zea mays L.) silage. Raw sorghum biomass has the advantage of lower lignin and ash content compared with maize and other perennial grasses used for biofuels. Environmental impact analysis of cropping systems have further demonstrated that integrating biomass sorghum has the added benefit of reducing the carbon footprint and eutrophication compared with maize in monoculture. In conclusion, high yielding forage sorghum cultivars can be used for production of bioenergy feedstocks in northern climates. More research focused on integrating biomass sorghum into current cropping systems is needed to produce food, feed, and energy, and to attain long-term sustainability and resilience of agricultural production in northern latitudes.