Nutrient content of fermented fertilizers and its efficacy in combination with hydrogel in Zea mays L

Purpose The nutritional content of fermented fertilizers was determined, and the effect of its application in combination with hydrogel was evaluated in a bioassay with maize plants. Methods The fertilizers were produced in artisanal biodigesters and the bioassay was carried out in pots with CP-569 maize. The nutritional content of the fermented fertilizers was evaluated, and in maize plants growth variables were measured, along with N–P–K contents in the aerial and root biomass. Results The types of biol show different characteristics for organic matter, N, N–NH 4 , N–NO 3 , P, K, Ca, Mg, Fe, Cu, Zn, Mn and B, as well as physical characteristics. The terms of the bioassay, the treatments with super absorbent polymer (SAP), biol and biol + SAP, showed significant statistical differences in terms of plant height, stem diameter and number of leaves 30 days after emergence. In the dry weight of aerial and root biomass, no statistical differences were found. In terms of the contents of N–P–K in biomass, statistical differences were found for P in aerial biomass and K in both aerial and root biomass. Conclusion Due to their physical and chemical properties, biols are an alternative to fertilizers. With the application of biol and SAP, maize plants undergo significant increases in height, stem diameter and number of leaves. By applying biol and SAP, the contents of N–P–K were not increased significantly in the aerial and root biomasses in comparison to the control.