Microplastics (MP) are being released into the environment at an increasing rate, causing extensive pollution in soils and affecting biota and processes. Although the use of biodegradable plastic has increased, its effects on the soil microbial community are not yet well understood. A controlled mesocosm experiment was conducted to investigate the response of soil microbial communities to increasing amounts of starch-polybutylene adipate terephthalate MPs (PBAT-BD-MPs) added to the soil. The experiment included microbes, earthworms, springtails, and plants. The PBAT-BD-MPs were added to the soil column at doses ranging from 0 to 0.8 % w/w of soil dry mass, and the columns were incubated for 11 weeks under controlled climatic conditions. Bacterial and fungal amplicon sequencing was used to investigate the dose-dependent response of the soil microbial communities' alpha and beta diversity. The alpha diversity indices of the bacterial and fungal communities increased with increasing PBAT-BD-MP concentration. Bacterial richness was highest at the highest MP concentration (0.8 %). A similar trend was observed in the fungal community, with a significant increase in fungal richness as PBAT-BD-MP concentration increased. The alpha diversity of both bacterial and fungal communities significantly increased in MP treatments compared to the control treatment. At the highest MP concentration (0.8 %), the abundance of the bacterial phylum Planctomycetes showed a significant increase, while Firmicutes showed a significant decrease. The abundance of the fungal phyla Ascomycota and Mortierellomycota also significantly increased at the highest PBAT-BD-MP concentration compared to the control group. Alongside changes in the soil microbial community, we observed a rise in soil respiration as the concentration of PBAT-BD-MPs increased. Our three-month mesocosm study demonstrates that the introduction of biodegradable microplastics into the natural standard soil environment in realistic concentrations (0-0.025-0.05-0.2-0.8 %) and particle size distribution alters the soil bacterial and fungal community.

The increasing use of agricultural plastics (APs) and resulting accumulation of microplastics (MPs) in soils potentially affects soil organisms. This study assessed the effects of polypropylene MPs derived from commonly used black ribbon and white fleece mulching fabrics on four soil invertebrates. Animals were exposed to MP concentrations of 0.005 % - 5 % in Lufa 2.2 soil to assess effects on survival, reproduction (Enchytraeus crypticus, Folsomia candida) and behavior (Eisenia andrei, Porcellio scaber). Both MP types dose-relatedly decreased soil bulk density, and increased soil water holding capacity at high concentrations. The MPs from white fleece mulching fabric also increased soil pH at all concentrations tested. Reproduction was affected more by MPs from black ribbon fabric than from white fleece mulching fabric, significantly affecting enchytraeids at 1 % and 5 %, and at 5 %, respectively, and springtails only at 5 % for the black ribbon fabric MPs. Earthworms avoided soil at 5 % of the first or 0.5 % and 5 % of the second MP type. Isopods seemed attracted, but also showed different walking behavior at 5 % of black ribbon fabric MPs. MPs derived from commonly used APs were shown to affect soil properties at low concentrations and the reproduction and behavior of soil invertebrates.

Today's agriculture faces many challenges. Due to intensive soil management, the widespread use of pesticides and fertilisers, biogeochemical fluxes are being disrupted, biodiversity is being strained, and soil degradation is becoming a major issue. Therefore, regenerative agriculture (RA), amongst other measures, has gained increasing attention. It aims to improve soil health and ecosystem services, needed to enable reliable food production with fewer negative impacts. However, field research on the impact of RA on the agricultural environment is scarce, especially in Europe. This research therefore investigates that impact, focusing on soil, plant health, and pesticide residues. The investigations took place on oilseed rape cultivated fields in the Swiss Plateau. The results showed a slight trend towards more favourable soil parameter values in the regenerative fields than in the conventional fields. This trend is underlined by significantly higher soil organic carbon values and, once site effects were accounted for, a significantly higher soil health index. The plant parameters showed no clear trend. Pesticide residues in the soil of regenerative fields were generally lower than in conventional fields in terms of the number of substances detected, their concentration and ecological risk, but varied considerably among the RA farms studied. Building on these findings and a review of recent literature, we propose refined, graded criteria for practice-based RA scoring. Together, the results support RA's potential to improve soil health and reduce reliance on pesticides, while highlighting the need for further research into yield trade-offs and a standardised definition of RA.