Start Date: Oct 16, 2007
End Date: Oct 15, 2012
An automated rainout shelter will be used to simulate drought conditions and test if early-season water stress and (or) defoliation following water stress will have greater impact on productivity of switchgrass or western wheatgrass or on mixtures of western wheatgrass and alfalfa. The influence of soil attributes on growth characteristics of perennial grasses will be determined with greenhouse evaluations using soil collected under native vegetation and under severely weed invaded plant communities at four sites between Mandan, ND and Pierre, SD. Field-based estimates of the greenhouse gases carbon dioxide and nitrous oxide will be used to determine if soil emissions of nitrous oxide offset carbon uptake by moderately grazed mixed-grass prairie. Satellite-based estimates of plant canopy carbon:nitrogen ratio will be determined for five native rangeland pastures and these estimates will be used to determine if they can be used to estimate forage quality for pastures on the northern Great Plains. Trials with cattle will be conducted to determine if grazing higher quality forages with supplemental flaxseed and (or) forages containing condensed tannin will result in reduced methane emissions per unit of beef produced and greater economic returns. Other trials with cattle will be conducted to determine if omega-3 fatty acid levels in beef can be raised substantially if fattening yearlings are fed flaxseed or flaxseed oil that is treated to protect the alpha-linolenic acid in it from hydrogenation by ruminal microbes.