BHUPAL RAJ, G.EBHIN MASTO, R.2018-06-082018-06-082000D6014http://krishikosh.egranth.ac.in/handle/1/5810050037Investigationsontheinteractionofphosphorusandmolybdenum onacidsoilsofhighaltitudeareasofSrikakulamandVizianagaramdistrictweretaken upwith soybean, anexpanding crop inthe area. These investigations include survey ofsoilstofindavailable Mo status, releasing pattern ofapplied M0 in acidsoils, effectofliming, PandMoapplication on thesoybean growth and yield.Theeffectofliming,PandMoapplicationonsoybeanuptakeandchanges inavailablePandMostatuswerealsostudied Laboratoryincubationandpot cultureexperimentwasconductedatAgriculturalResearchInstitute,Rajendranagar during 1999-2000. Thetreatments consisted two levels ofliming (O and 3.5 t ha"1basedonlimerequirement),twolevelsofP(Oand 10mgPkg'l)andthree levelsofMo(0,0.25and0.5mgMokg'l).Thetrialwaslaidoutincompletely randomiseddesignwithfactorialconceptandreplicatedthrice.Thetestcropwas soybean variety JS—335. The effect ofabove variables were also studied in laboratory incubation study as used forpot experimentinthree categoriesof soilshavingpHof4.35,5.03and5.7. Inthe84soilsamplescollectedduringthesurveyindifferentvillagesspreadover12mandalsinthehighaltitudeareaofSrikakulamandVizianagaramdistricts, about56percentofthesoilswereacidichavingpH_<_6.5.Therestofthesoils were either neutral oralkaline. Available Mo contentofthesesoilsranged from0.029to0.389mgkg"1withameanof0.17] mgkg‘l,DeficiencyofM0 was noticed in49.3percentofthesoilsamplescollected. Meliaputti mandal ofSrikakulamdistrictandKurupammandalofVizianagaramdistrictwereobserved tohaveModeficiencytoalargerextent.TheavailableMocontenthadasignificant positivecorrelationwithpH,EC,0Cand P content, butnegativecorrelation withtheclaycontent. Moapplicationtothesoil upto05mgkg'] favourably increasedthedrymatteraccumulation, podsperplant,seedyieldandcontentanduptakeofN, PandMo.HighestN.P andMouptakewasobservedwith IOmgkg'1 P. Liming@ 3.5 I ha'1 (as per lime requirement) significantly increased the dry matter, podsperplant,seedyieldandnutrientuptake. Limeandphosphorusinteractioneffectondrymatterproduction,podsperplant, seed yield and nutrient uptakewas significant. The highest seed yield (9.07 g pot'l) was observed with application of 10 mg P kg'] after liming, InteractioneffectoflimeandMowassignificantondrymatterproduction,pods plant' 1, seed yield and nutrient uptake. The highest seed yield obtained was 9.19 gpot"1 with application of0.5 mgMo kg.l after liming. A synergistic P and Mo interactionwas observed on dry matterproduction, pods plant—1. seed yieldanduptakeofN,PandMo.Highestseedyieldof9.ogpot'1wasobtained with 10mg P kg'1 applied alongwith0.5mgMokg?! Lime,P,Mointeraction was alsopositively significant ondrymatterproduction.podsplant—l.seedyield anduptakeofN,PandM0.Theseedyield(9.63gpot—i)obtainedwithapplication of10mgPkg'l+0.5mgMokg"afterlimingwassignificantlyhigherthanin all othertreatmentcombinations. Lime,PandMoapplicationsignificantlyincreasedtheavailableP andMo contentinthesoilduetoincubattoninthethreeaCldsoilsstudied.Theinteraction effectsofthesevariableswerealsosignificantinincreasingtheavailablePand Mocontents.HigherPandMocontentswerennullThesis