Accumulation of microplastics (MPs) in agricultural environments has caused growing concern in recent years because of its detrimental impacts on soil quality, crop productivity and ecosystem function. This study was conducted to assess the impact of biochar on soil chemical and microbial properties in a MP-contaminated soil under two moisture regimes. Soil was contaminated with 1% (w/w) of low-density polyethylene MPs. Four types of standard biochar, that is, oil seed rape (OSR) biochar produced at 550°C (OSR 550) and 700°C (OSR 700) and soft wood pellet (SWP) biochar produced at 550°C (SWP 550) and 700°C (SWP 700), were applied at a rate of 5% (w/w). The control was maintained without MP addition. The samples were incubated in soil with two moisture regimes, that is, at 30% and 70% of the water holding capacity, and the soil chemical and microbiological properties were assessed after 100 days of incubation. OSR biochar application significantly increased soil pH (8.53–8.81) and electrical conductivity (0.51–0.58 dS/m) in both moisture regimes. The effect of biochar application on soil enzyme activity and microbial community composition did not show a clear trend. However, SWP 700 biochar improved soil enzyme activity compared with that of the control and improved bacterial diversity and evenness compared with those of other biochars, which was attributed to the high surface area available for microbial colonization. Low soil moisture content significantly reduced enzyme activity and bacterial richness even with biochar amendment, except for SWP 550 biochar. This study implies the suitability of biochar for improvement of soil quality in MP contaminated soil under both moisture regimes. However, further long-term studies are needed to get a clear understanding on the impact of different types of biochar on MP-contaminated soil.
Bibliographical noteFunding Information:
This work was carried out with the support of the Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ01475801) from Rural Development Administration, the Republic of Korea. This work was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. 2021R1A2C2011734). This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF‐2021R1A6A1A10045235). Authors also acknowledge Subin Kim for his support for his contribution for sample analysis.
© 2022 British Society of Soil Science.
- UN SDGs
- low-density polyethylene
- plastic mulch
- sustainable waste management
- waste valorization
ASJC Scopus subject areas
- Agronomy and Crop Science
- Soil Science