Ecosystem Services Provided By a Novel Perennial Grain Kernza Wheatgrass.

Perennial grain cropping systems may be able address a number of seemingly intractable environmental problems associated with annual crop production, such as soil degradation and subsurface nitrate leaching to waterways. Kernza wheatgrass (Thinopyrum intermedium) is a new perennial grain crop currently under development to provide high quality, nutritious grain and a number of regulating and supporting ecosystem services. In order to determine the ecosystem services provided by this cool season grass, we quantified grain and biomass yields, nitrate leaching, soil C pools, and energy use over four years of kernza wheatgrass relative to annual winter wheat (Triticum aestivum). Overall, differences between annual wheat and perennial kernza were pronounced and driven largely by yearly weather patterns. Annual wheat yielded greater grain, but produced less overall aboveground biomass than kernza wheatgrass. Total nitrate leaching was comparable in the establishment year, but kernza reduced total nitrate leaching in the subsequent years by 85 – 99% relative to annual wheat. Perennial kernza increased soil organic carbon and labile organic matter pools relative to annual wheat indicating greater allocation of belowground productivity. Although current yields are modest, the realized ecosystem services of this developing crop in the first four years of production are promising and opportunities currently exist for planting this crop in environmentally sensitive areas of agricultural farmland.