Biodigester effluent as fertilizer for water spinach established from seed or from cuttings

摘要

Asplit-plotdesignwasusedtostudygrowthofwaterspinach(Ipomoeaaquatica)nbsp;asaffectedbythetypeofplantingmaterial(seedsorstems)andbybiodigestereffluentnbsp;(0,50,100,150and200kgN/ha)usedasfertilizer.Freshbiomassyieldsafter24dayswerehigher(15tonnes/ha)whenwaterspinachwasestablishedfromseedthanfromstemcuttings(9.18tonnes/ha).BiomassyieldofwaterspinachincreasedlinearlywitheffluentNlevelwhenplantedfromstemcuttingsandlogarithmicallywhenplantedfromseed.TheNcontentofwaterspinachleavesincreasedfrom3.08to5.56%inDM(19.3to34.8%crudeprotein)nbsp;byapplicationof200kgN/haasbiodigestereffluent.StemsweremuchlowerinN(1.2to2.0%inDM)andthisindextendedtodecreasewithincreasingapplicationofeffluentN.WaterextractableNtendedtobehigherinleavesthaninstemsbuttheconversewastrueforthewaterextractableDM.WaterextractableDMinleavesandstemsincreasedwithlevelofeffluentNupto100kg/habutthendeclined.EffluentNlevelhadnoeffectonnbsp;waterextractableN.Itisrecommendedtoestablishwaterspinachfromseedratherthanfromstemcuttings.