Browsing by Subject "perennial grain"

Now showing 1 - 5 of 5
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    Intermediate Wheatgrass Nitrogen Dynamics: Nitrate Leaching Prevention and Nitrogen Supply via Legume Intercrops
    (2021-07) Reilly, Evelyn
    We compared soil and soil water nitrate concentrations, root biomass, and yield in intermediate wheatgrass (IWG; Thinopyrum intermedium) and a corn-soybean rotation over three years. Nitrate was 77-96% lower under IWG than the annual system, while root biomass was higher. IWG grain yields were 854, 434, and 222 kg ha-1 for Years 1-3 and biomass averaged 4.65 Mg ha-1 yr-1. IWG effectively reduces soil solution NO3--N concentrations even on sandy soils, supporting its potential for broader adoption on vulnerable land. We also assessed grain and biomass yield and N dynamics in response to mineral fertilizer and six legume intercrops. Treatments affected N dynamics and IWG biomass but not grain yields. N transfer rates ranged from 0 to 27% but legume biomass was negatively associated with IWG grain yield, suggesting competition in addition to nitrogen supply. Overall, alfalfa, red clover, and birdsfoot trefoil were among the best options for intercrops.
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    Kernza® Perennial Grain in 40 Milestones
    (2023-06) Reilly, Evelyn C
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    Milestones in Kernza® Perennial Grain Development
    (2023-08-16) Reilly, Evelyn C
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    Root Structure, Biomass Allocation, And Legume Intercropping Of Intermediate Wheatgrass
    (2023-08) Griffin, Alexandra
    Intermediate wheatgrass (IWG; Thinopyrum intermedium) is a perennial grass undergoing domestication as a grain crop, whose deep roots can reduce soil erosion and nutrient pollution. One barrier to the viability of IWG as a grain crop is an interannual decline in seed production, the cause of which is unknown. Both experiments in this thesis aim to uncover plant density-dependent relationships associated with a decline in seed production and guide future strategies to increase yield stability. The first chapter investigates the effects of intercropping legumes on IWG in two row spacings. Intercropping legumes was not found to increase IWG seed or biomass production, however, rarely did intercropping impose net competitive effects. The second chapter investigates root structure and biomass allocation using minirhizotrons. Greater root abundance was not linked to lower aboveground productivity in IWG, which suggests that IWG does not experience a biomass allocation trade-off between above- and below-ground plant tissues.
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    Soil physical, chemical, and microbial community responses to two years of perennial Intermediate Wheatgrass versus annual maize/soybean management systems
    (2023-01) Link, Emma
    Intermediate Wheatgrass (IWG, Thinopyrum intermedium (Host) Barkworth & D.R. Dewey; IWG) is a perennial grain crop with a dense root system which has the potential to facilitate improvements in soil physical structure, fertility, and potentially soil carbon storage. An experiment was established in Rosemount, MN, USA to assess changes in soil physical, chemical, and microbial community responses to IWG system vs. annual corn/soy system management after two growing seasons. This experiment aims to 1) assess soil quality under four systems representing a gradient of perenniality, cropping system diversity and soil disturbance intervals and, 2) investigate relationships between soil microbial community characteristics and desired soil chemical and physical quality outcomes to better understand the mechanisms behind desired outcomes. In the first chapter of this study, we report the agronomic outcomes of the first two years of the experiment and examine how IWG vs. annual crop management affect soil chemical and physical properties over the course of two growing seasons. After two years, we find that the proportion of large water stable soil aggregates at 15-30 cm soil depth increased significantly in IWG but not IWG-alf intercropped systems compared to annual systems. We also find evidence of increased water use deep in the soil profile by IWG systems under drought conditions. In the second chapter, we investigate the responses of soil microbial community composition and potential function to two years of IWG vs. annual management. We find that after two years, fungal community composition varied significantly by cropping system and IWG systems are associated with increased arbuscular mycorrhizal fungi biomass and AMF indicator species. We also find evidence of greater extracellular enzyme activity in IWG systems and an annual system with cover cropping.