Maturity indices as an index to evaluate the quality of sulphur enriched municipal solid waste compost using variable byproduct of sulphur

•Developing maturity indicators for sulphur enriched municipal solid waste compost.•Organic sulphur fertilizer prepared with MSW was well matured and stabilized.•Distinct variations were observed in sulphur fractions, NH4+-N, NO3-N and Olsen-P.•Sulphur enriched composts could be used as supplement of costly chemical fertilizers. The aim of this study was to assess the maturity indicators of municipal solid waste compost (MSWC) enrichment with different byproduct of (sugar and fertilizer industry) sulphur (S). The concentration of total S (TS), water-soluble S (WSS), HCl extractable S and available S were significantly different in composts prepared through different byproduct of S with MSW. WSS varied from 4.6 to 5.9% of TS after 120 days of the composting period, whereas, available S varied from 14.5 − 8.6% of TS. S enriched MSW compost had lower C/N, C/S ratio and higher nitrification index as well as lower phyto-toxicity, demonstrating that composts are properly matured and stabilised. Highest compost quality index (0.97) was recorded with S1 compost. Arylsulphatase activity significantly increased with compost maturity. Results stated that all S enriched products maintained a superior amount of plant nutrients and quality indices, indicating that S enriched compost could be a possible substitute for expensive fertilizers.