Using bioelectrohydrogenesis left-over residues as a future potential fertilizer for soil amendment

Area of Science:

• Agricultural Science
• Environmental Science
• Microbiology

Background:

• Agricultural straw wastes are abundant and pose disposal challenges.
• Current inorganic fertilizers are costly and can have negative environmental impacts.
• Dark fermentation-microbial electrolysis cells (DF-MEC) offer a method for waste bioconversion and energy production.

Purpose of the Study:

• To investigate the potential of DF-MEC residues as a biofertilizer.
• To analyze the microbial communities and nutrient content of the residues.
• To evaluate the impact of these residues on plant growth.

Main Methods:

• Utilized activated sludge in a DF-MEC system for agricultural straw bioconversion.
• Analyzed the microbial composition of the DF-MEC residues.
• Quantified macro- and micronutrients within the residues.
• Applied MEC-effluent as a biofertilizer to tomato, chilli, and brinjal plants.

Main Results:

• Residues were rich in plant growth-promoting microbes like Enterobacter, Paenibacillus, and Pseudomonas.
• Microbial communities capable of producing phytohormones (IAA, Gibberellins) and fixing nitrogen/solubilizing phosphate were identified.
• Adequate concentrations of essential macro- and micronutrients (N, P, K) were detected.
• Application of MEC-effluent significantly enhanced plant growth, flowering, and fruit production.

Conclusions:

• DF-MEC residues are a viable and sustainable alternative to costly inorganic fertilizers.
• This technology provides a novel approach for agricultural waste management.
• The developed biofertilizer is eco-friendly and cost-effective, promoting crop yield.