Adaptation, and possibly a broad rethinking, of agricultural management is urgently needed for reducing carbon emissions while simultaneously maintaining economic viability of rural agricultural communities . Perennial grain crops may be part of the solution to these multilayered challenges. For example, intermediate wheatgrass (IWG), a new perennial wheat-like grain crop, has deep extensive root systems that can improve terrestrial carbon sequestration and soil functionality through reduced soil disturbance, continuous plant cover, and the fostering of functionally diverse microbial communities. At the same time, newly emerging markets for these perennial grain crops present a viable alternative to farmers wishing to diversify their cropping systems. In this study, we examined carbon budgets and short term microbial indicators of improved soil function of several cropping systems that include intermediate wheatgrass (IWG), a new perennial grain crop. As an additional factor, systems both with and without IWG include different plant diversity levels over time. Cropping systems were established in fall of 2016. Plant above and belowground biomass, grain yield, photosynthetic capacity, microbial biomass and activity, and carbon emissions were measured during the first two years of cropping system establishment.
Results/Conclusions
We see evidence that even in these early years of establishment, cropping systems that include IWG are storing more carbon. Although CO2 emissions appear to be higher in IWG cropping systems early in the season, this is offset by the increased leaf area index and biomass present in IWG cropping systems. Belowground biomass in particular was much greater in IWG cropping systems, representing a large carbon input into the system. Over time, there is also a downward trajectory of microbial biomass carbon in non-IWG annual systems, whereas microbial biomass appears stable in the perennial IWG. Intermediate wheatgrass supports active microbial communities that may mediate the decomposition and storage of the large carbon inputs in these perennial systems. In summary, these novel perennial cropping systems may lead to an improved agricultural carbon budget as well as other environmental benefits associated with that stored carbon such as soil quality and functionality.