Forms of phosphorus of vermicompost produced from leaf compost and sheep dung enriched with rock phosphate

Introduction Vermicomposting could increase nutrientsavailability including phosphorus. During vermicomposting,a decomposition of organic substrates leads to theproduction of several organic acids, such as malonic,fumaric, succinic acids. Microorganisms both in theintestinal organ of the worms and the organic waste havethe ability to convert insoluble P into soluble forms. Littleinformation exists about the effects of vermicomposting onrock phosphate (RP) solubilization. Present study wasconducted to evaluate the solubilization of powdered RPduring vermicomposting.Results Vermicomposting and RP application increasedNaHCO3-Pi. Rock phosphate application in vermicompostingsignificantly increased NaHCO3-Po. Vermicompostingsignificantly increased NaOH-Pi in all of thetreatments. RP application and vermicomposting increasedHCl-Pi in both organic sources. Generally, vermicompostingincreased HCl-Po. Vermicomposting decreased pHbut its effect was more evident in the presence of RP.Vermicomposting increased EC in both organic sources.Conclusion Present study showed that vermicompostinghelps to enhance the transformation of P from RP intovarious organic or inorganic P forms, which would bereadily or moderately available, thus, increase the availabilityof P from both RPs.