Understanding the Impact of Polymer-Coated Fertilizers

Marine plastic pollution is a pressing concern, shedding light on the necessity to manage plastic disposal in agricultural practices. A recent study in Ishikawa Prefecture, Japan, delves into the seasonal and daily variations of microplastics from polymer-coated fertilizers in agricultural rivers throughout the irrigation period of April to October for 2021 and 2022. The findings are enlightening.

Key Findings:

Microcapsule Concentrations: The mean microcapsule concentration ranged from 0.0 to a striking 783.2 mg/m3 over the study period.

Seasonal Variations: Notably, concentrations exhibited distinct seasonal patterns, reaching their peaks in late April and late May, with median values of 55.5 mg/m3 in 2021 and 62.6 mg/m3 in 2022.

Correlation with Outflows: The timing of this concentration increase coincided with the outflows from paddy fields, strongly suggesting that microcapsules flowed quickly from the paddy fields to the sea after the outflow.

Microcapsule Size and Distribution: The microcapsules typically measured 2-4 mm, corresponding to primary microplastics.

Accumulation and Transport: The use of polymer-coated fertilizers leads to the accumulation of primary microplastics in paddy fields. Some of these microcapsules degrade in the soil, resulting in the formation of secondary microplastics.

Sustainable Solutions and the Urgency of Microplastic Separation Technologies:

The application of plastic materials in agriculture has significantly strengthened crop production. One prominent advancement is the use of polymer-coated fertilizers, which offer precise control of component diffusion, reducing labor and overall fertilizer application. However, the challenge arises post-fertilization, as the removal of polymer coatings, referred to as "microcapsules," from fields is both time-consuming and costly.

The Critical Need for Microplastic Separation Technologies

The separation of microplastics must be seriously considered in agriculture. The development of efficient microplastic separation technologies is essential to reduce the impact on the environment and ensure sustainable agricultural practices that are in line with the well-being of the planet.

In conclusion, this study highlights the urgent need to apply microplastic removal technologies in agriculture. On the path to agricultural progress, it is of utmost importance to achieve a balance between progress and sustainability. Through continued research and innovation, we can chart a path towards responsible agricultural practices that ensure a healthy environment while supporting agricultural growth.

Reference : https://doi.org/10.1016/j.envpol.2023.121422