Selection of Switchgrass for Reclaimed Mineland.

A major advantage of growing switchgrass (Panicum virgatum L.) for cellulosic ethanol production is the ability of plants to produce high levels of biomass when grown on marginal soils not suitable for agronomic crop production.  It is not known, however, if plants can be selected for high biomass in prime soils and have similar yield levels when grown in marginal soils.  Therefore, the objective of this research was to determine whether selecting plants for traits in prime soils would reflect similar performance when grown in reclaimed mineland soils.  Seventy-five maternal switchgrass lines from both the Rutgers University and Cornell University switchgrass breeding programs were planted in 2013 at one location with prime soil (either Freehold, NJ or Ithaca, NY) and one reclaimed mine land with marginal soil (Philipsburg, PA).  Measurements included visually assessing the plants for vigor (rating scale of 1 – 10, 1 = very poor growth) and determining biomass yield at the end of the growing season.  Significant differences in vigor ratings were detected for the switchgrass lines grown in both prime and marginal soils.  Biomass yield ranged from 289 – 2,536 g DW plant^-1 at the prime site and 0 – 425 g DW plant^-1 at the marginal site for the Rutgers switchgrass lines.    Similarly, yields were significantly lower at the marginal site (14 – 340 g DW plant^-1) compared to the prime site (160 – 1040 g DW plant^-1) for the Cornell lines.  Overall, 16 lines from the Rutgers populations and 14 lines from the Cornell populations were identified as having higher vigor scores and better yields at both the prime and reclaimed mineland sites compared to all other lines evaluated.  This suggests that selection for vigor on prime farmland looks promising to improve biomass yield on reclaimed mineland.