Poloxamer-Enabled Thermoresponsive Biobased Controlled-Release Fertilizer for On-Demand Nutrient Delivery

Synchronizing nutrient release of fertilizers with crop uptake remains a central challenge in precision agriculture. Here, we present a novel temperature-responsive biobased controlled-release fertilizer (TRBFs) incorporating Poloxamer 407 (F127) as a thermal switch within a castor oil-derived polyurethane coating. The optimized TRBF10 (3 wt.% coating rate, 10 wt.% F127 in coating) exhibits a sharp, reversible phase transition at ∼20°C, matching the phenological requirements of overwintering crops. As quantified by digital refractometry, the 30-day cumulative nitrogen release is suppressed to 9.22% at 10°C (crop dormancy) and increases 8.7-fold to 80.32% at 30°C (active growth). This scalable technology overcomes intrinsic limitations of conventional diffusion-controlled coated fertilizers and offers potential for on-demand nutrient delivery with reduced environmental loss. Our work establishes sustainable strategies for climate-adaptive precision agriculture and offers new insights and design paradigms for intelligent controlled-release materials.