Establishment of an erosion-control plant cover in a sand pit under Arctic conditions using sewage sludge

This paper presents the findings of a prolonged field studies that ained to assess the feasibility of using the sewage sludges (SS) form a regional water and wastewater services enterprise to expedite the establishment of a resilient erosion-control plant cover in sand pits located in the Arctic region of the Russian Federation. The study confirms the beneficial impact of the SS on the seed germination, subsequent growth, and development of plants. The study shows that SS can be used in two ways: first, by applying a continuous layer measuring 5 to 10 cm thick on the soil surface or by fragmentarily applying a layer 2-3 cm thick. Second, through early-winter sowing of seeds directly on the soil surface (under the SS layer) or on top of the sewage sludge. In both cases, an annual enhancement of the qualitative and quantitative parameters of the artificially formed stand of grass was observed. This included a significant increase in its height and density, biomass, foliage cover, and thickness of the formed sod, in contrast to the reference sample. The present study investigates the characteristics of the floristic composition of the phytocenoses formed in a sand pit. The findings demonstrate that the use of sewage sludge (SS), regardless of the quantity and application method, accelerates the restorative succession in the sand pit. The thick stand in the experimental variants, resulting from the attraction of pioneer vegetation, promotes the complexity of its structure and species composition, rapid vegetation of inner bare areas, and the emergence of natural phytocenoses elements that are specific to the zonal type of vegetation. Additionally, the use of SS stabilizes erosion processes in the study ares. Consequently, the plant community formed in the experiment using SS can be classified as ecologically sustainable, with the potential for independent existence and further development. These results can serve as a foundation for monitoring efforts and the development of measures to optimize the vegetation of such ecotopes.