CNPq PhD Scholarship - An Investigation of Plant Growth and Associated Soil Microbial Stimulation by Digestate Fertilisers

PhD Project on grassland microbiology. Investigated composition of anaerobic digestates and their effect when applied to grassland soils (both field and pot trials).

Anaerobic digestate is the by-product left over after biogas is made. It contains nutrients and microbes and can be used as a fertiliser. The project investigated the composition of digestate from various biogas plants and looked into whether they stimulated plant growth in field and pot trials.

Digestates varied widely in nutrient and microbial composition, but mostly met recommendations for fertilizer use and were found to stimulate plant growth. Plant-growth-promoting microbial species were detected in digestates, but they failed to establish in significant numbers once the digestates were applied to soil.