Soil denitrification stimulated by macroplastics in maize cultivation

Yanyan Zhang ¹, Joann Whalen ², Yuhang Liu ³

¹College of Resource, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China; College of Agronomy, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China; Key Laboratory of Investigation and Monitoring, Protection and Utilization for Cultivated Land Resources, Ministry of Natural Resources, China; International Science and Technology Cooperation Base for Efficient Utilization of Nutrient Resources and Fertilizer Innovation, Sichuan Provincial Department of Science and Technology, Chengdu 611130, China.
²Department of Natural Resource Sciences, McGill University, Macdonald Campus, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
³College of Resource, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China.
⁴Key Lab of Land Resources Evaluation and Monitoring in Southwest, Ministry of Education, Sichuan Normal University, Chengdu 610068, China.
⁵Research Center for Environmental Ecology and Engineering, Key Laboratory of Green Chemical Engineering Process of Ministry of Education, School of Environmental Ecology and Biological Engineering, Wuhan Institute of Technology, 206 Guanggu 1st road, Wuhan 430205, China.
⁶College of Resource, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China; Key Laboratory of Investigation and Monitoring, Protection and Utilization for Cultivated Land Resources, Ministry of Natural Resources, China.
⁷College of Agronomy, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China.

⁰College of Resource, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China; College of Agronomy, Sichuan Agricultural University, 211 Huimin Rd., Chengdu 611130, China; Key Laboratory of Investigation and Monitoring, Protection and Utilization for Cultivated Land Resources, Ministry of Natural Resources, China; International Science and Technology Cooperation Base for Efficient Utilization of Nutrient Resources and Fertilizer Innovation, Sichuan Provincial Department of Science and Technology, Chengdu 611130, China.

Journal of Hazardous Materials +

|

October 18, 2025

View abstract on PubMed

Summary

Macroplastics in agricultural soils harm maize root development and reduce nitrogen uptake. This can increase nitrogen loss through denitrification, impacting crop yield.

Area Of Science

Agricultural Science
Environmental Science
Soil Science

Background

Macroplastics (> 2 cm) are an emerging pollutant in agricultural soils.
Their impact on nitrogen (N) cycling and crop performance, particularly in maize cultivation, is poorly understood.
Maize-based intercropping systems are widely promoted globally.

Purpose Of The Study

To investigate the effects of macroplastics on soil-plant nitrogen dynamics in maize-soybean intercropping systems.
To assess the impact of macroplastics on maize growth, root development, and yield.
To analyze microbial-mediated nitrogen transformations under macroplastic contamination.

Main Methods

Mesocosm and field experiments were conducted.
Macroplastic treatments were applied to maize-soybean intercropping systems.
Soil nitrogen concentrations, plant growth parameters, and microbial N-transforming activities were measured.

Main Results

Macroplastics had minimal impact on aboveground maize morphology and yield but significantly inhibited root development.
Soil nitrate-nitrogen concentrations decreased, while nitrite reductase activity and 15N retention increased, indicating reduced N uptake by maize.
Abundance of denitrifying bacteria and genes increased, suggesting a higher potential for nitrogen loss via denitrification.

Conclusions

Macroplastic exposure in intercropped maize systems does not significantly alter aboveground growth but impairs root development and nitrogen uptake.
Contamination leads to soil conditions favoring nitrogen loss through denitrification.
Managing denitrification is crucial for improving nitrogen use efficiency and crop yields in macroplastic-polluted agricultural soils.

Keywords:

Denitrification Intercropped maize Nitrogen Plastic pollution Soil

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