Food security is a global concern that needs to be faced with strategies that allow actual and future generations to satisfy an ever-growing demand. However, our present agriculture practices to enhance crop yields use excessive fertilizers, which has a negative impact in the environment and resource conservation. In particular, phosphorus (P) is the second most important macronutrient for plants after nitrogen. When P is applied as fertilizer, its efficient use is reduced as a result of complexation reactions and leaching in soils, generating contamination of water and soils. Such environmental issues can be minimized by slow-release fertilizers (SRFs), which are fertilizer particles coated or encapsulated by a polymer matrix that enables nutrients to be released over an extended period, maintaining a continuous nutrient supply. Nevertheless, the current use of synthetic polymers as encapsulating matrices generates additional environmental issues because accumulation of non-biodegradable residues in soil.<br/>In nature, the outermost layer of plant surfaces is covered by cuticular waxes, whose varied chemical composition, crystallinity, and porous structure permit water and nutrient transport control. Therefore, we take advantage of these features of natural waxes to develop of slow-release phosphate fertilizers. In this work, Carnauba wax from a Brazilian palm tree and Candelilla wax from the wild candelilla plant of Mexico are used as encapsulating matrices for slow release of phosphate fertilizers. Using an encapsulation technology by spray chilling, microencapsulates containing 40 wt.% of phosphate fertilizer are obtained with distinctive molecular and morphological features that provide different slow-release behaviors. Considering the abovementioned features, new insights in fertilizer release mechanisms based on plant cuticle models are discussed.

Plant cuticular waxes as renewable encapsulating matrices for phosphate fertilizers: Morphological insights into phosphate release behavior

255th National Meeting (2018)

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