We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Impact of Microplastic Contamination on Phosphorus Availability, Alkaline Phosphatase Activity, and Polymer Degradation in Soil
Summary
Researchers studied how different types of microplastics at various concentrations affect phosphorus availability and enzyme activity in soil. They found that microplastics altered phosphorus cycling both by directly supplying phosphorus in some cases and by changing microbial enzyme function. The study suggests that microplastic contamination could disrupt soil nutrient dynamics important for maintaining agricultural productivity.
Microplastics (MPs) are emerging contaminants that can significantly impact soil nutrient dynamics, particularly phosphorus (P) cycling, which is critical for maintaining soil fertility and ecosystem productivity. However, limited information is available on how different microplastic types and concentrations specifically influence phosphorus dynamics and microbial enzyme activity in soils. Microplastic contamination may alter P cycling by directly supplying phosphorus or indirectly influencing microbial activity and enzyme function through changes in soil structure and aggregation. This study examined the short-term impacts of three widely used microplastic polymers-polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET)-on soil phosphorus forms and alkaline phosphatase activity (APA), a key enzyme in phosphorus transformation. Incubation experiments were conducted at two concentrations (0.5% and 5%) over 30 and 60 days. The results indicated that the impact of microplastics on soil phosphorus dynamics varied according to both polymer type and contamination dose. Microplastics increased available phosphorus (AP) and APA levels compared to control soils, indicating a stimulatory effect on microbial processes. This may be due to the temporary accumulation of phosphorus on MP surfaces, which can stimulate phosphatase activity. Over time, however, both AP and APA levels declined, suggesting that degradation products released from MPs and organic matter may have altered the activity of the microbial communities responsible for P cycling. FTIR analysis revealed clear degradation of microplastics, with PET showing the most pronounced chemical transformation. PP exhibited moderate degradation, while PE demonstrated the highest resistance to environmental breakdown. These degradation processes likely released functional groups (e.g., carboxyl, carbonyl, hydroxyl) and low-molecular-weight compounds into the soil, modifying microbial processes and phosphorus chemistry. Particularly in PET-amended soils, these degradation products may have enhanced phosphate complexation or mobilization, contributing to higher levels of available phosphorus at the end of the incubation time. Understanding the polymer-specific and concentration-dependent effects of microplastics is critical for accurate ecological risk assessment in terrestrial ecosystems.
Sign in to start a discussion.
More Papers Like This
Insight into the transformation of phosphorus in soil affected by microplastics: A review
This meta-analysis found that microplastics significantly decrease phosphorus availability in soil by 7-56%, driven by particle characteristics, soil properties, and exposure duration. Microplastics alter phosphorus cycling through adsorption, changes in soil chemistry, shifts in microbial communities, and modified phosphatase activity, with implications for farmland fertility management.
Effects of microplastic properties and dissolved organic matter on phosphorus availability in soil and aqueous mediums
Researchers studied how different types of microplastics from agricultural mulching films affect phosphorus availability in soil and water. They found that both conventional plastics like polyethylene and biodegradable plastics like polylactic acid significantly reduced available phosphorus in soil, with smaller and more concentrated particles causing the greatest reductions. The study suggests that microplastic accumulation in agricultural soils may impair nutrient availability for crops.
Microplastics and Soil Nutrient Cycling
Microplastics accumulating in agricultural soils can disrupt the natural cycling of carbon, nitrogen, and phosphorus by altering microbial communities and reducing soil enzyme activity. This review highlights that even at current environmental concentrations, microplastics may impair the soil ecosystem functions that underpin food production, though the full extent of effects on nutrient cycles remains incompletely understood.
Discrepant effects of microplastics on soil phosphorus availability under different phosphorus fertilizer applications
Researchers studied how polyethylene and polylactic acid microplastics interact with different types of phosphorus fertilizers in soil over 56 days. They found that microplastics reduced the amount of plant-available phosphorus in organically fertilized soils by up to 29%, while increasing it in soils treated with mineral fertilizer. The findings suggest that microplastic contamination in farmland could alter how effectively crops access essential nutrients depending on the fertilizer type used.
Assessing Microplastic Contamination Effects on Soil Microbial Communities in Agricultural Land
This study sampled agricultural soils with varying degrees of microplastic contamination to assess effects on microbial diversity, abundance, and enzymatic activity, finding that higher microplastic concentrations reduced microbial diversity and suppressed nutrient-cycling enzyme activity.