Microplastics (MPs) in soil can paradoxically stimulate microbial biomass in a highly context-dependent manner, potentially inducing decomposition and affecting carbon and nitrogen cycles. We conducted a global meta-analysis with 90 studies (710 observations of microbial biomass carbon (MBC), 354 of microbial biomass nitrogen (MBN)) integrated with machine learning to quantify MPs effects on soil microbial biomass. Field studies showed no significant effects, contrasting with controlled experiments where MPs increased MBC by 9.6% (95% CI: 7.2–11.9%) and MBN by 10.4% (6.8–14.0%). Biodegradable plastics (PBAT, PLA) induced stronger effects (36.1–67.6%) than conventional polymers (PE, PP, PS, PVC). Temperature emerged as the dominant factor, with a contrasting MPs effect on MBC (positive) and MBN (negative) at higher temperatures, suggesting potential decoupling of carbon and nitrogen cycles under warming conditions. Machine learning models (XGBoost, R2 = 0.62) significantly outperformed linear regressions (R2 = 0.02–0.05), revealing nonlinear responses and threshold effects. Stimulatory effects were most significant for medium-sized MPs (30–90 μm), at high concentrations (>10 g kg–1), and in soils with intermediate fertility, highlighting context-dependent risks to soil carbon and nitrogen cycling.

There is uncertainty in whether there is a common pattern of nestedness and modularity in plant–arbuscular mycorrhizal (AM) fungi associations, partly because of limitations arising from the use of ...

Data-driven scientific discovery requires iterative cycles of literature search, hypothesis generation, and data analysis. Substantial progress has been made towards AI agents that can automate scient...

Can we establish a culture of experiments to try out new forms of collaboration, research, and teaching?

During 2025 and 2026, Art Laboratory Berlin is unfolding the new innovative project CHRYSALIS. ARTISTS IN LABS with an interdisciplinary exchange between art and science in Berlin science laboratories...

Suzgun et al. find that current large language models cannot reliably distinguish between belief, knowledge and fact, raising concerns for their use in healthcare, law and journalism, where such disti...

Hopes of securing a United Nations treaty on plastics pollution are fading after the final round of negotiations ended without an agreement.

Increasing the speed of scientific progress is urgently needed to address the many challenges associated with the biosphere in the Anthropocene. Co...

Letter to the Editor

Letter to the Editor

Some thoughts....

Well, I think: never. But how this led to maybe a more interesting question....

And no, they are not a dime a dozen....

Long-term intercropping represents a key strategy to boost productive and ecological benefits. However, its potential to mitigate soil carbon-climate …

Applications for European research grants increased in 2025. Scientists say they’re feeling the competition.

Die Erde unter unseren Füßen trägt uns, ernährt uns – sie ist Grundlage unseres Lebens. Doch was wissen wir eigentlich über sie? Matthias Rillig zählt zu den führenden Forschern auf dem Feld der Boden...

Was wir "Unkraut" nennen, rettet Bienen - und "Schädlinge" pflegen den Boden. Unsere Sprache unterschätzt die Natur. Zeit für ein Umdenken?