Despite an increasing concern of consequences of using vast amounts of glyphosate-based herbicides in agroecosystems, their potential effects on non-target soil organisms and soil functioning are mostly unknown. It has also been argued that fields in northern latitudes should be under special surveillance as the short active period of decomposers may restrict glyphosate degradation. We investigated the effects of a glyphosate-based herbicide, Roundup, on the abundance of enchytraeids and nematodes, both essential groups in decomposer food webs, and plant litter mass loss and soil availability of mineral N in a two-year agricultural field setting in south-west Finland. Our experiment consisted of (1) non-treated weed plots, (2) plots, where weeds were killed by hoeing, and (3) plots treated with both Roundup and hoeing. We found that killing plants by hoeing had drastic effects on soil fauna and functioning, and apparently, distinguishing these effects from direct glyphosate effects is profoundly important when evaluating glyphosate risks in soils. In contrast, the effects of Roundup on soil fauna and functioning were minor and transient and no glyphosate remains were found in the soil at the end of the experiment. These results suggest that side-effects can be minor and glyphosate degradation effective also in soil under northern climatic conditions.

The feasibility of thermochemical biomass conversion technologies can be improved if value-added applications for all fractions can be developed. One of such approaches is the use of liquid by-products from slow pyrolysis and hydrothermal carbonization (HTC) in plant protection. Liquids produced from slow pyrolysis of pine bark, pine forest residues, wheat straw, and willow, and from hydrothermal carbonization of willow, were analyzed in this study. In particular, potential active compounds were analyzed, covering the main volatile, simple organic compounds and numerous phenolic substances. Effectivity tests of the liquids as pest repellent (Arianta arbustorum), herbicide (Brassica rapa), and insecticide (Rhopalosiphum padi) indicated that slow pyrolysis liquid from willow was the most effective pesticide, followed by the liquid from wheat, bark, and forest residues. HTC liquid did not show any pesticidal activity due to low concentration of organic compounds. High content of acetic acid and other carboxylic acids, and the presence of dozens of different phenolic compounds seem to be the main reason for the higher pesticidal activity of willow-derived pyrolysis liquid. Temperature-separated slow pyrolysis liquids proved to be suitable to be used as pesticides. Consequently there is possibility to improve the feasibility of thermochemical biomass conversion technologies remarkably by developing the liquid factions to value-added pesticides.

The impacts of climate change on ecosystem structure and functioning are likely to be strongest at high latitudes due to the adaptation of biota to relatively low temperatures and nutrient levels. Soil warming is widely predicted to alter microbial, invertebrate, and plant communities, with cascading effects on ecosystem functioning, but this has largely been demonstrated over short‐term (<10 year) warming studies. Using a natural soil temperature gradient spanning 10–35°C, we examine responses of soil organisms, decomposition, nitrogen cycling, and plant biomass production to long‐term warming. We find that decomposer organisms are surprisingly resistant to chronic warming, with no responses of bacteria, fungi, or their grazers to temperature (fungivorous nematodes being an exception). Soil organic matter content instead drives spatial variation in microorganism abundances and mineral N availability. The few temperature effects that appear are more focused: root biomass and abundance of root‐feeding nematodes decrease, and nitrification increases with increasing soil temperature. Our results suggest that transient responses of decomposers and soil functioning to warming may stabilize over time following acclimation and/or adaptation, highlighting the need for long‐term, ecosystem‐scale studies that incorporate evolutionary responses to soil warming.

Pesticide residues in agricultural soils represent an environmental concern that requires special attention due to their potential ecological and public health risks. We analyzed 614 pesticides in 188 wheat fields across Europe subjected to both conventional and organic farming systems. At least one pesticide residue was detected in 141 soils. Seventy-eight pesticides or their metabolites were detected. The presence of pesticides was significantly higher in both number and concentration in conventional fileds (up to 0.98 mg kg^-1) compared to organically managed sites (up to 0.40 mg kg^-1). A total of 88 % of conventional fields and 63 % of organic fields contained two or more pesticides. Conversion from conventional to organic farming does not guarantee that soils will be pesticide-free in the short term. Fenbutatin oxide was the most frequently detected pesticide in both farming systems, followed by AMPA. Other substances, such as boscalid, epoxiconazole, diflufenican, tebuconazole, dinoterb, bixafen, and DEET, were found in ≥ 10 % of samples. Some Persistent Organic Pollutants, including dieldrin, endosulfan sulphate, and chlorpyrifos, were also detected. Ecological risks were higher in conventionally managed fields, with 46 % exhibiting high-risk levels, compared to just 1 % in organic fields. Epoxiconazole and boscalid were the substances with the highest risk levels.

In the northern boreal zone, revegetation and landscaping of closed mine tailings are challenging due to the high concentrations of potentially toxic elements; the use of nutrient-poor, glacigenic cover material (till); cool temperatures; and short growing period. Recycled waste materials such as biochar (BC) and composted sewage sludge (CSS) have been suggested to improve soil forming process and revegetation success as well as decrease metal bioavailability in closed mine tailing areas. We conducted two field experiments in old iron mine tailings at Rautuvaara, northern Finland, where the native mine soil or transported cover till soil had not supported plant growth since the mining ended in 1989. The impacts of CSS and spruce (Picea abies)–derived BC application to till soil on the survival and growth of selected plant species (Pinus sylvestris, Salix myrsinifolia, and grass mixture containing Festuca rubra, Lolium perenne, and Trifolium repens) were investigated during two growing seasons. In addition, the potential of BC to reduce bioaccumulation of metals in plants was studied. We found that (1) organic amendment like CSS markedly enhanced the plant growth and is therefore needed for vegetation establishment in tailing sites that contained only transported till cover, and (2) BC application to till soil-CSS mixture further facilitated the success of grass mixtures resulting in 71–250% higher plant biomass. On the other hand, (3) no effects on P. sylvestris or S. myrsinifolia were recorded during the first growing seasons, and (4) accumulation of metals in cover plants was negligible and BC application to till further decreased the accumulation of Al, Cr, and Fe in the plant tissues. Graphical abstract