Various sulphur fractions changes during different manure composting

The simulation experiment of aerobic composting was adopted to explore the various sulphur (S) fractions change during six manure composting. The total S, various S fractions and available S concentration was markedly different among six manures because of different animal species and diets. Total S concentration decreased especially during 0–14d composting for all manures. The change trend of water-soluble S, adsorbed S and available S concentration firstly increased, then decreased during different manure composting, and the change trend of organic S concentration was opposite to above them. HCl-soluble S concentration has been increasing during composting. High concentration of water-soluble S, adsorbed S and available S was gained as an effective S fertilizer when composting was stopped at 28 d. During composting, organic S and HCl-soluble S were main S fractions to affect total S change, and available S could come mainly from water-soluble S and adsorbed S.