Abstract

The application of humic substances (HS) to plants stimulates their biochemical-physiological mechanisms, growth and development. Humified materials exhibit structural characteristics that allow interactions with heavy metal cations dissolved in aqueous environments. Due to their high availability, agriculture-derived vermicomposts (VC) (agro-materials) are excellent raw materials for obtaining HS. Based on these properties, it might be possible to develop biotechnology processes that use agro-materials for environmentally sustainable agriculture. The present article describes the application of a biotechnological working protocol that uses cattle manure vermicompost (CVC) as a raw material for HS. The suggested protocol includes six steps based on the structure-property-biological activity relationships of all the resulting agro-materials. Both the CVC and the resulting agro-materials were characterized using various chemical-physical and spectroscopic techniques. The agro-materials not only increased the agricultural production of different crops at the optimal sowing seasons but also increased production under water and saline stress conditions. The residues arising from the protocol processes were analyzed and found to be useful as decontaminants of heavy metals in aqueous liquid effluents. In addition, the use of such products resulted in increased profits for small- and medium-scale farmers. These studies suggest that agriculture-derived composted organic materials are viable for sustainable agroecological use.

Key words: Vermicompost, humic substances, humic acids, stress.