Hot Mess: Heatwave Effects on Controlled-release Fertilizer

Abstract

Controlled-release fertilizers (CRFs) are water-soluble pellets of homoor heterogenous mineral nutrients covered with polymer or resin that become increasingly porous as temperature increases, releasing water-soluble fertilizer through diffusion. An experiment was carried out at the North Willamette Research and Extension Center located in Aurora, OR, USA (lat. 45°1605100N, long. 122°4500400W) with six fertilizer concentrations of a CRF fertilizer that was designed to last 6 to 7 months at 70 °F. During the experiment, the Pacific Northwest experienced a series of early-summer (June) heatwaves that caused an unanticipated and excessive release of mineral salts. Extreme weather adaptation strategies are necessary to sustain horticultural production in a period with increased temperature volatility.