Decadal change in soil carbon and nitrogen with a Miscanthus × giganteus crop on abandoned agricultural land in southeast Ohio

Abstract Miscanthus × giganteus (miscanthus) is considered a beneficial biomass energy crop because of its carbon (C) sequestration potential and low fertilizer requirements, but few studies in the United States have measured long‐term C sequestration of miscanthus on suboptimal agricultural lands over a decadal scale, and none have been conducted in southeast Ohio. The objective of this study was to measure the soil C sequestration on abandoned agricultural land with a miscanthus crop that is harvested annually, the long‐term changes in plant and soil nitrogen (N), and the photosynthetic capacity in the tenth year of growth. This study was conducted over a 10‐year period from 2013 through 2023. A significant amount of C was accumulated in the soil ( p 0.05). There was no statistically significant change in the amount of N found in soil and plants over 10 years ( p > 0.05), but the variability in plant N was greater in some years relative to others. Even though miscanthus was grown without N fertilizers in this study, soil N at 0–30 cm depth was not depleted over 10 years of crop management. The photosynthetic capacity of miscanthus measured in this study indicated that the plants were thriving after 10 years, and C assimilation for growth was consistent with the findings of prior work that evaluated the maximum photosynthetic rates of this species. The combination of significant soil C sequestration, sustained soil N, and high photosynthetic rates has important implications for the sustainability of miscanthus as a biomass crop.