Characterization and Use of Absorbent Materials as Slow-Release Fertilizers for Growing Strawberry: Preliminary Results

Anaerobic digestion is one of the most important and advantageous processes in livestock manure treatment. Digestate, one of its byproducts, contains particularly high nitrogen levels that determine storage and disposal costs. Excess nitrogen can be managed through sequestration processes. This study assesses the potential of natural zeolite to adsorb ammonium ions from a simulated ammonium-rich digestate, and to verify its absorbency and efficiency to release fertilizer slowly to strawberry plants. The assessment considered the effects on the plant, fruit quality, prokaryotic abundances and relative abundance of bacterial and archaeal functional genes related to nitrification. Our results confirm that ammonium-enriched zeolites possess positive implications for strawberry plants and favorably influence bacterial nitrification. Natural zeolites demonstrated high sorption properties and were shown to be an efficient carrier of N to plants.