Journal of Soil and Water Conservation

Salt-impacted soils are formed through anthropogenic or natural causes. In the northern Great Plains region of North America, salts that occur in the soil parent materials move upward through the soil profile due to changing land-use and precipitation regimes. If these salts accumulate in the surface soil layer, they impact the ecological integrity of a site, creating the need for ecological restoration. Common methods for addressing salt-im-pacted soil were developed in the irrigated soils of the southwestern United States and are often ineffective in noncrop areas and the northern Great Plains due to differences in soil properties, elevated gypsum concentrations, and poor soil drainage. Therefore, the objective of this study was to identify native plant species suited for revegetation in salt-impacted soils in the northern Great Plains region of North America. This field study evaluated the survival and performance of eight native plant species in soils with high, medium, or low salt concentrations. Survival was evaluated at summer and end-of-season sampling (five months total) and performance variables (plant height, basal diameter, number of flowering heads, number of tillers/stems, and aboveground biomass) were evaluated at end-of-season sampling. Seven of the eight species evaluated exhibited some salt tolerance and could be suitable for the revegetation of moderately salt-impacted soil. Overall, Asclepias speciosa, Gaillardia aristata, and Helianthus maximiliani grew in minimally salt-impacted soils, whereas Elymus canadensis, Elymus trachycaulus, and Pascopyrum smithii grew in moderately salt-impacted soils, and only Sporobolus airoides grew in highly salt-impacted soils. As these native plants establish and grow, they will spur autogenic recovery by stabilizing soil structure and improving water movement in the soil. These results indicate that salt tolerance must be considered when selecting species that could revegetate these areas.

Our prior study showed that a dormant seeded rye (Secale cereale L.) cover crop reduced carbon dioxide equivalence (CO2e) in a frigid submesic climate. However, this research did not discuss the impact of the cover crop on temporal changes in soil inorganic nitrogen (N), soil organic carbon (SOC), microbial biomass, and community structure, which is the purpose of the present study. In this replicated no-tillage study, winter cereal rye was drilled in October of 2018 and 2019 and terminated using glyphosate (N-[phosphonomethyl] glycine) on June 11, 2019, and June 8, 2020, at the V4 growth stage in corn (Zea mays L.). Rye biomass collected at termination was air dried and placed into fiberglass litter bags at a rate of 3,750 kg ha–1. Bags were placed on the soil surface at the original collection zone. Four replicate bags from each plot were collected after 87, 248, and 365 days. Following removal, the material remaining in the removed bags was analyzed for amount and chemical composition. The decomposing cover crop biomass increased the microbial biomass and the amount of soil inorganic N and SOC in the surface 15 cm at 365 days (one year after litter was applied). These results suggest that soil nutrient benefits from fall-planted rye cover crop may not occur until the year following termination. However, the N credit benefits may vary depending on the type of cover crop, such as legume or brassica; therefore, this should also be considered in future studies. Overall, these findings provide practical implications for cover crop management in frigid submesic climates, suggesting that growers’ adoption of cover crops can improve soil health, enhance crop yields, and reduce reliance on chemical fertilizers, thereby contributing to more sustainable and economically viable farming systems.