Effect of potassium nitrate as modifier of the fermentation in an in vitro incubation using as substrate NaOH and/or lime treated straw supplemented with fresh cassava leaves

摘要

Theaimofthisstudywastoevaluatetheeffectofcombiningalkalitreatmentofricestrawwithnon-proteinnitrogen(NPN)fromnitrateinreducingmethaneproductioninaninvitroincubationsystem.Thetreatmentsinasplit-plot2*6arrangementwithfourreplicationswere:alkalitreatedstrawwithNaOH(0;1;2;3;4%)pluslime(Ca(OH)2)(4;3;2;1;0%)oruntreatedstraw,andasNPNsourcenbsp;potassiumnitrateorurea.Alltreatmentshadfreshcassavaleafasproteinsource.nbsp;Thequantityofsubstratewas12gtowhichwereadded240mlrumenfluids(fromslaughteredbuffalo)and960mlofbuffersolution.Theincubationwasfor24hwithmeasurementsoftotalgasproduction,nbsp;methanepercentageatintervalsof4;8;12;16and24hoursanddeterminationofresidualunfermentedsubstrateattheend.Theproportionofsubstratefermentedafter24hwasincreasedbyalkalinbsp;treatmentandtendedtoincreaseaslimereplacedNaOH.Totalgasproductionandmethanepercentagenbsp;increasedwithnbsp;incubationtimenbsp;andnbsp;werereducedwhennitratereplacedureanbsp;atallnbsp;fermentationstages.After24h,themethaneproductionperunitoffermentedsubstratewaslesswhennitratereplacedurea.Itisconcludedthatnbsp;lime)canreplaceNaOHasameansofincreasingthefermentabilityofricestrawandthatmethaneproductionisdecreasedwithpotassiumnitratenbsp;asNPNsource.