Enhancing Bioavailability of Fertilizer through Amyloid-Like Protein Coating.

Abstract

Foliar fertilization acts as a ubiquitous component of conventional crop production because the nutrients can be absorbed more quickly than soil fertilizers, which brings considerable economic and ecological costs. Due to droplets rebounding and splashing during spraying and rain erosion, low bioavailability of fertilizer results in soil salinity, heavy metal accumulation, water eutrophication and the greenhouse effect. Contrary to conventional fertilizer formulations with polymers, surfactants, and organic reagents, we herein present a method of improving fertilizer bioavailability based on a biocompatible protein coating. In this system, whey protein concentrate (WPC) can undergo amyloid-like aggregation after the reduction of its disulfide bond by the reducing agent tris(2-carboxyethyl) phosphine (TCEP). Such aggregation affords a fast formation of the optically transparent and colorless phase-transitioned WPC (PTW) coating at solid/water interface, with robust interfacial adhesion stability. Upon packaging with fertilizers through electrostatic and hydrogen bonding interactions, such reliable interfacial adhesion thereby facilitates the effective deposition of fertilizers on superhydrophobic and hydrophobic leaf surfaces, with excellent adhesion stability under sufficient exposure to simulated weather conditions. In this regard, the PTW coating shows the highest fertilizer retention capability in all known outcome, even under rainfall conditions that are 100 times more intense than those described in literature. High optical transmittance of the PTW also does not affect normal photosynthetic capacity of plant. Based on further practical farmland test, this work experimentally demonstrates that the application of an amyloid-like protein aggregation could significantly boost the bioavailability of fertilizers and decrease at least 30% fertilizer use in large-scale crop planting. This innovative strategy has the great potential to offer a transformative step forward in managing fertilizer contamination and overuse in future agriculture. This article is protected by copyright. All rights reserved.