0
Meta Analysis Tier 1 Environmental Sources Human Health Effects Marine & Wildlife Sign in to save

Do Added Microplastics, Native Soil Properties, and Prevailing Climatic Conditions Have Consequences for Carbon and Nitrogen Contents in Soil? A Global Data Synthesis of Pot and Greenhouse Studies

Environmental Science & Technology 2024 53 citations

AI summary Read the abstract

This meta-analysis examined how microplastics affect carbon and nitrogen levels in soil, which are key to soil fertility. The results show that certain types of plastics — especially smaller, fiber-shaped particles — can significantly alter soil chemistry, potentially affecting crop growth and soil health.

Study Type Review

Microplastics threaten soil ecosystems, strongly influencing carbon (C) and nitrogen (N) contents. Interactions between microplastic properties and climatic and edaphic factors are poorly understood. We conducted a meta-analysis to assess the interactive effects of microplastic properties (type, shape, size, and content), native soil properties (texture, pH, and dissolved organic carbon (DOC)) and climatic factors (precipitation and temperature) on C and N contents in soil. We found that low-density polyethylene reduced total nitrogen (TN) content, whereas biodegradable polylactic acid led to a decrease in soil organic carbon (SOC). Microplastic fragments especially depleted TN, reducing aggregate stability, increasing N-mineralization and leaching, and consequently increasing the soil C/N ratio. Microplastic size affected outcomes; those <200 μm reduced both TN and SOC contents. Mineralization-induced nutrient losses were greatest at microplastic contents between 1 and 2.5% of soil weight. Sandy soils suffered the highest microplastic contamination-induced nutrient depletion. Alkaline soils showed the greatest SOC depletion, suggesting high SOC degradability. In low-DOC soils, microplastic contamination caused 2-fold greater TN depletion than in soils with high DOC. Sites with high precipitation and temperature had greatest decrease in TN and SOC contents. In conclusion, there are complex interactions determining microplastic impacts on soil health. Microplastic contamination always risks soil C and N depletion, but the severity depends on microplastic characteristics, native soil properties, and climatic conditions, with potential exacerbation by greenhouse emission-induced climate change.

More Papers Like This

Meta Analysis Tier 1

Differential impacts of microplastics on carbon and nitrogen cycling in plant-soil systems: A meta-analysis

AI summary Read the abstract

A meta-analysis of 3,338 observations found that microplastics increased soil CO2 emissions by 25.7% but also boosted soil carbon storage through increases in total carbon (53.3%), soil organic carbon (25.4%), and microbial biomass carbon (19.6%). However, microplastics decreased plant aboveground biomass and reduced nitrate and ammonia volatilization, suggesting that while soil carbon sink capacity may increase, agricultural productivity could suffer.

Meta Analysis Tier 1

Global hierarchical meta-analysis of microplastic-induced changes in the soil nitrogen cycle

AI summary Read the abstract

This global meta-analysis found that microplastics significantly disrupt soil nitrogen cycling, with high concentrations (>1%) and smaller particle sizes causing the most severe effects on nitrogen transformation processes. These disruptions to soil fertility and microbial communities could ultimately reduce crop productivity and threaten food security.

Article Tier 2

Effects of microplastics on soil C and N cycling with or without interactions with soil amendments or soil fauna

AI summary Read the abstract

A meta-analysis of soil experiments found that microplastics significantly disrupt carbon and nitrogen cycling — the fundamental processes that keep soils fertile and regulate greenhouse gas emissions — especially when microplastics interact with fertilizers, heavy metals, or soil animals like earthworms. The type of plastic and the presence of other stressors compounded the effects, with some combinations causing substantially greater disruption than either factor alone. This matters because agricultural soils are heavily contaminated with microplastics from mulch films and other sources, threatening both food production and climate regulation.

Meta Analysis Tier 1

Global Responses of Soil Carbon Dynamics to Microplastic Exposure: A Data Synthesis of Laboratory Studies

AI summary Read the abstract

This meta-analysis combined data from 110 studies to understand how microplastics change the way carbon moves through soil. The findings suggest that plastic pollution can disrupt natural soil processes, which may affect soil health and the planet's ability to store carbon.

Meta Analysis Tier 1

Effects of microplastics exposure on soil inorganic nitrogen: A comprehensive synthesis

AI summary Read the abstract

Meta-analysis of 216 observations from 47 studies showed microplastics exposure significantly reduced soil nitrate concentration by 7.89% overall, but had no significant effect on ammonium. Microplastic polymer type was the strongest predictor of nitrate effects, and exposure above 27C actually enhanced soil nitrate, highlighting a concerning interaction with global warming.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper