Location: Dale Bumpers Small Farms Research CenterTitle: The role of perennial forages in reducing spatiotemporal yield variability when integrated into annual cropping systems
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/8/2020
Publication Date: N/A
Technical Abstract: When incorporated into annual cropping systems, perennial crops can provide multiple ecosystem service and crop production benefits. Previous findings from a study conducted in Mandan, ND suggested that 3 yr of a perennial phase consisting of alfalfa monoculture (PALF) and 4 to 5 yr of an alfalfa-intermediate wheatgrass binary culture (PALF+IMWG) were needed to provide yield increases in a spring wheat crop as compared to fertilized continuous spring wheat (CWF) crop. Further, perennial forages provided near-surface soil benefits with PALF+IMWG and an intermediate wheatgrass monoculture (IMWG), specifically, resulting in reduced soil bulk density and soil acidification and increased particulate organic matter and water stable aggregates as compared to CWF. Production and soil analyses indicated high inter-block and inter-annual variability, especially between fields which had been historically used for grass breeding trials. This study will investigate the ability of perennial forage crops to reduce field variability over time (spatio-temporal variability). Further, we will conduct exploratory analyses to determine the role of perennial forages in stabilizing subsequent annual crop yields and enhancing resistance to climactic perturbations. Initial results suggest variability of perennial forage biomass production, as measured by coefficient of variability, showed the greatest and most consistent decline in the PALF+IMWG binary culture, from 31 to 7 % over five years (2010-2014). Declines in percent variability were also observed in IMWG and switchgrass (SWG) monocultures, from 25 to 15 and 36 to 21 %, respectively. Trends were more erratic in the PALF+SWG binary culture and variability increased in the alfalfa monoculture. Ongoing analyses will further decipher these trends and provide insight into a possible additional ecological service these multifunctional crops can provide.