Biodegradable Polymers for Plant Nutrient Delivery and Recovery

The current use of fertilizers is inefficient and not sustainable. The majority of the fertilizer applied does not reach the targeted crop but is lost in the water bodies and into the atmosphere, with harmful impact on the environment. To enhance the efficiency and sustainability of current agricultural practices, it is essential to address two complementary challenges. First, nutrient delivery methods must be refined to maximize plant uptake. Second, the recovery of nutrients from wastewater and other waste streams should be improved to enhance the recycling of nitrogen and phosphorous and reduce environmental pollution. Biodegradable polymers hold great promise for the development of technological solutions toward more sustainable agricultural practices. This review covers the application of biodegradable polymers in both aspects of the nutrient cycle: nutrient delivery to plants through slow- and controlled-release fertilizers, and nutrient recovery from wastewater using membrane separation, adsorbent composites, and coagulants/flocculants. The most promising materials are highlighted for both approaches, identifying the research gaps and discussing potential future directions in this highly significant field.