The plastic shells from polymer coated urea persist for more than 12 months in the field.
![](https://eatlas.org.au/sites/default/files/styles/m_very_large/public/nesp-twq-5/5-11/residual_PCU_granules_12_months_after_application_Silkwood.jpg?itok=4F8Z4Ufi)
Photographers: Bronwyn Masters
Description
Controlled release fertilizer products have used plastic or polymer coats to regulate fertilizer N release into the surrounding soil. Granule coatings are slowly permeable, allowing N to diffuse into surrounding soil over time, but the residual plastic shells can persist in the environment long after the N has been released.
Image produced for the project