SUSTAINABILITY, cilt.15, sa.11, ss.1-17, 2023 (SCI-Expanded)
A high
pH, low solubility of bound plant nutrients, and negative impacts on microbial
communities are common drawbacks of biomass ash (BA) vermicomposting. In this
study, nutrient-rich BA mixed with cow manure was tested at three different
application rates to obtain final nitrogen (N), phosphorus (P), and potassium
(K) contents of 3.5%, 7.0%, and 10.0% for bio-based fertilizers via
vermicomposting. The results showed that all BA blends made with cow manure
increased fermentation temperatures and allowed successful worm activity during
the subsequent vermicomposting phase. The order of indicator enzyme activities
in all vermicomposting samples was urease (220 μg NH4 g−1
h−1) > β-glucosidase (95 μg PNP g−1 h−1)
> alkaline phosphatase (91 μg PNP g−1 h−1) >
arylsulfatase (83 μg PNP g−1 h−1) > acid phosphatase (60
μg PNP g−1 h−1). As an indicator of nutrient
bioavailability, high correlations were observed between enzyme activities and
microbial diversity in vermicompost samples. Determination coefficients (R2) obtained from multiple linear regressions between
enzyme activities and bacterial population for T0, T1, T2,
and T3 were determined as 0.90, 0.65, 0.73, and 0.90, respectively.
According to a novel metagenome-based approach proposed within the scope of the
present study, the stimulatory effects of Flavobacteriales,
Burkholderiales, Saccharimonadales, and Pseudomonadales
on enzyme activities for the nutrient solubility were found to be significant
and positive. The findings of this study demonstrated that worm composting
could be a sustainable bio-based technology for the production of slow-release
fertilizer from nutrient-rich waste material.