Conservation tillage practices were tested against autumn mouldboard ploughing for differences in physical properties of soil, surface runoff, subsurface drainflow and soil erosion. The study (1991 -2001) was performed on a gently (2%) sloping clayey soil of southern Finland, with two replicates of the tillage treatments on 0.5 ha plots. The annual shares of surface runoff of the total flow (surface runoff + subsurface drainflow) were 8–42% for ploughing (depth 20–23 cm), 36–66% for shallow autumn stubble cultivation (depth 5–8 cm) and 36–82% for soil left untilled over winter. Surface runoff increased with decrease in the tillage intensity, and in line with the values of depressional water storage, macroporosity and saturated hydraulic conductivity. Erodibility of this gently sloping soil was at highest after autumn and spring tillage operations and decreased with time. Shallow autumn tillage produced erosion as high as mouldboard ploughing (407–1700 kg ha–1yr–1), but 48% and 12% lower erosion levels were measured from plots left untilled in autumn, covered by grass or barley residues, respectively. Eroded soil particles moved relatively freely to the subsurface drains, which carried 37–94% of the annual soil losses from the field. The study shows that even on the relatively flat clayey soils typical for southern Finland, tillage has a great influence on soil losses. The frequency of tillage needs to be reduced rather than the depth of tillage on clayey soils with poor water conductivity and structural stability if soil loss is to be diminished by conservation tillage.;

Conversion of dissolved P by ferric sulfate into a particulate form sparingly available to algae was studied in 15 ditches in Finland using stand-alone dispensers for ferric sulfate administration. Ferric sulfate typically converted 60–70 % of dissolved P into iron-associated form, a process which required 250–650 kg per kg dissolved P. Mean cost was 160 EUR per kg P converted (range 20–400 EUR kg−1). The costs were lowest at sites characterized by high dissolved P concentrations and small catchment area. At best, the treatment was efficient and cost-effective, but to limit the costs and the risks, ferric sulfate dispensers should only be installed in small critical source areas.

In this review paper, we investigate the management of the quality of stormwater in the Baltic Sea region. Current stormwater management practices, standards, and legislation do not accurately depict stormwater quality, resulting in an underestimation of its environmental impact. The digitalization and harmonization of stormwater management through the implementation of e-monitoring (online or continuous monitoring) allow for the collection of data. This data can be used to improve stormwater quality and quantity management, thereby reducing the environmental harm induced by anthropogenic activities. Based on the literature review, supporting tables and matrices are proposed to assist decision-makers and other interested parties in developing and implementing “smart” stormwater management solutions. In this article, we demonstrate that such systems can enhance stormwater management and system performance by leveraging data-driven operation and maintenance. Another advantage of the approach is that it contributes to a healthier urban environment and ecosystem well-being.