Evaluation of Biomass Production by Perennial Grasses in Eastern Ontario.

The abundance of marginal land in Eastern Ontario and its proximity to major industrial areas in the heart of North America could give this region a golden opportunity in the production of biomass grasses. The objective of this study is to evaluate the effect of species/variety, planting densities and nitrogen fertilizer rates on biomass production. Two switchgrass (Panicum virgatum L.) varieties, two big bluestem (Andropogon gerardii Vit.) varieties and one Indiangrass (Sorghastrum nutans Nash.) variety were seeded in 2009 in eastern Ontario to evaluate their biomass production potential. The crops were seeded in a loamy sandy soil with three seeding rates; 10, 14 and 18 lb PLS/ac, referred to as SR1, Sr2, and SR3, respectively. No fertilizer was added in 2010. In 2011, treatment N2 received 50 kg N/ha while no nitrogen was applied to treatment N1. The crop biomass production and harvest moisture content were determined in November 2010 and December 2011.

The two higher seeding rates slightly increased biomass production in 2010 for switchgrass and big bluestem. Southlow switchgrass was the highest producer in 2010 with an average biomass production of 6.51 Mg/ha, followed by Cave-in-Rock switchgrass. The two varieties of big bluestem produced around 3.00 Mg/ha, while Indiangrass averaged only 2.30 Mg/ha. With regard to 2011 production, N application increased production only in big bluestem, while seeding rate had no effect. Cave-in-Rock switchgrass production topped all grasses, with an average production of 11.8 Mg/ha for treatment SR2-N1. Prairie View big bluestem ranked third with production as high as 7.88 Mg/ha for treatment SR3-N2. Moisture content at harvest was not affected by the seeding rate or nitrogen application, but was rather species dependent. With the stands reaching their peak production, this study shows the high production potential for some of these grasses under Ontario conditions.