Evaluating nanocellulose from food waste as a functional amendment for sandy soils: Linking fiber structure to water dynamics, soil mechanics, and plant-microbes interactions

Micro and nanofibers have the ability to imbue control over water transport properties and mechanical cohesion to granular materials. These key characteristics are proportional to the fiber size, if finely tuned, and can enable soils to more effectively host life. Typically, requirements include a high organic matter content, a rich microbiome, and especially physico-chemical properties conducive to water dynamics. Herein, we developed mechanochemical processes to fibrillate food-waste-based biomass (namely, peels) into a range of fiber solutions. Macrofibers and nanofibers were obtained via mild processing steps and were fully characterized, the relation between the morphology as well as physico-chemical properties of the fibers was thoroughly studied. Three sand types associated with deserts were evaluated for their potential benefits from the fiber amendments. The compressive response of the amended soils and, more importantly, their water holding, water permeability, and evaporation rate were thoroughly evaluated. The resistance of reinforced soil matrices to biodegradation and dry-wet cycling was also used to evaluate long-term performance. Finally, this study provides an outlook on nutrient retention for agricultural endeavors as a function of fiber amendment type and content.