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POTASSIUREML EASING ANDS UPPLYINPGO WER OFS ELECTEYDE LLOWG REYE ARTHS OILOSF NEW ZEALAND A thespirse senitnpe adtir alf ulfilmoeftn hter equiremfeontrtsh ed egroefe DoctoofrP hilosoipnSh oyiS lc ienactMe a sseUyn iversity ARAVI ND SURAPANENI 1994 ii ABSTRACT Thes upployf s oiplo tassi(uKm)t oN ew Zealanpdas turiessc urrenbetilnyga ssessed byt heq uictke sKt ( QTK)a ndr eserKv (eI(., )m etohdsw,h icmhe asurseo il exchangeKa b(lKee xa)n dn on-exchangKe (aKb..elxer) e's pectiQvTeKl yi.sb asedo n a routisnoeit le satn dI(., isa na ssigneesdt imaatep proaptretoi thes oiglr oupN.o cosnideraitsig oinv etnot hev ariatoifot nhseK. .esxu pplwyi thai ns oiglr oupT.h e objectoifvt eh iresse arcwha st oe xaminteh e rKe leasainndKg supplypionwge orf selcetesdo iflrso mt hey ellow-gearthr ey( YGEgr)o up. A widev ariatwiaoson b serveidnt hem easurI(.,ed v aluoefst heY GEs oiilsnt he Nortahn dS outh IslAa ngdlsa.s shoeuxsep erimsehnotw etdh atth es upployf K..etxo ryegragsrso wonn t he1 3N orthI slaYndG Es oirlasn gefdr om0 -4m1g 100 g.a!n d thaotf t he6 S outIhs laYndG Es oirlasn gefdr om3 -3mg5 1 00 g.!T.h ee xperiment alssoh owetdh atth erwee rel owelre veolfsK ..exs uppliynt hep astusriet ecso,m pared tot hev irgsiint weisth r espetcott h eS outIhs laYndG Es oilThse.s er esulhtasv e implicattioto hneus se oft hes oiglr oucpo ncewphti cihs u setdo e stimaKt..eex suppliynt heC omputeriFseerdti lizer AdSveirvsiocr(eyC FASK) modelc,u rrently usebdy A gResearch. Ina labotroarsyt udtyh,et hreshKo llde veilnst erms K ocfo ncentraantdit ohne activriattyii not hee quilibsroaitsleo dl utiKoenxa,'n dt hea mounotf s pecifichaellldy K wered etermiinneo dr,d etroe xplatihnev ariatiinoKu nesxs u pplTyh.e t hreshold K levewlesre notr elatteotd h eK nexr eleaasneds upply. Theu ptakoefK byr yegrawsassa tbe stp oorltyom oderatceolrrye lawtietdth h eK extracbtyec du rrenmte thodosfd eterminKi nrge leapsoiwnegvr i zQ,T K and1(., . Theh ighessitm plceo rrelawtaisoo bnt ainferdo ma ni mprovaecdi d-reaxcttaKb le procedu(rre= 0.9P6< ; 0 .01Th)e. d ifferenicnte hse K uexu ptakbey r yegrafsrosm various wseoriebl est teexrp laibnyea d s implmee thod doeft erminisnogiKuex l i.e., steKp, t habny t hee xistI(.,i nmge thodA. m ultiprleeg resseiqouna tiwoint QhT K iii ands tep asKi ndeepndenvta riabelxepsl ai9n6e%d oft hev ariatiinto ont Ka l uptakea mongs olis. On theb asiosfK. .ext akeunp b yr yegrasisnth e glasshoeuxspeei mrenthte, 19s oils int hisst udwye reb roadglryo upiendt o ctawtoe gor(iis)eo si ls swtietKph v aluoefs lestsh a3n 5m g 100 g'a!n da K" rangoef 8 -1m0g 100 g'a!n d( iis)o iwlist sht eKp valugerse attehra 3n 5m g 100 g'a!n da K" rangoef 1 2-1m9g 100 g'!. Selectseodiw lesr ef ractioinnetsdoa nds,i latn,dc lasye paraatnedas c id-exttarblaec K leveolfst hef ractiwoenrsem easureTdh.e rwea sa wider angien tahcei d­ extractKa lbelvee almso ngt hes oiflosr t hes ames izfer actei.ognc. l,a ya,n df or differseinzfter actiwointsh tihne s ames oiLW henw eightaecdc ordtiont gh e partiscilzede i stribuotfit ohnes oitlh,es anwda sf ountdo c ontribu4t-e4 %5, s il1t0 - 40% ,a ndc la1y 5-8%5 o ft heK releabseydt hes umo ft he3 separatuessi,n tgh e improvaecdi edx tractmieotnh odI.na ll stohiel tsh,ec lasye pararetlee asethde m ost K peru niwte ight. An agapro tt ritaelc hniwqaused evelopteomd e asutrhee K supplypionwge orf th e soisle paratAelst.h ouognha uniwte ighbta sitsh ec laseyp aratsehso wead m uch greataecrt ivtihtaytn h eo theserp aratoensa weightbeads itsh,ec ontribuotfis oannsd ands ilste parattoet sh et otKa lu ptakoefM arto(n3 %8) M,a tapi(r4o1% ),an d Wharekak(a2 %5) s oiwlsa so fc onsideriambploert ancTeh.e resduelmtosn strated thatth er oloef s anadn ds ilste paradteesse rvmeo rec onsideriante isotni mating potentKi raell easainndsg u pplypionwge trh ahna sh itheberetno t hec ase. Thes tudayl saot tempttoe dre lK.at.eerx el ease andt ots hueps polimyli neralogy. Althoutghheg ross mineorfat lhoe1g 9ys oiwlass s imildairf,f ereinnct ehseK. .ex releaasneds upplcyo ulbde re latetdos ubtdlief fereanncdeg sr adual chiantn hgee s clamyi neraloTghye.X RDp atteornfst hec lays aw iK"t rha ngoef 8 -1m0g 100 g'! ofs oidli ffefrreodmt hoswei tah K" rangoef 1 2-1m9g 100 g'o!f s oiTLh el atter grouopf c laycso ntamionr eK bearimnign eratlhsat nh ef ormerg roup. Thep ractiicmapll icatoifto hnes measduirfefde reinnc� e vsa lue(s� xs upply) withitnh eY GEs oiglr ouwpe red ealwti thT.h em easure�dx suppliynt heN orth IslaYndG Es oirlasn gefdr om2 0-4k0gh a·y!r ·w!h,e retahse e xpecte�dx supply baseodn a na ssignK.:e vda luies3 0k gh a·y!r "!T.h ed ifrfeencbee tweethne expectaenddt hem easurK.e.ed xma yb es ufficieecnotnloym icsailglnyi fiacsta on t invaliadpaptley ian sgi ngK.:le v aluteoa soiglr oupP.o ssiibmlper ovementtsot he soiKl s upply compoofnth een CtF ASK modewle res uggestpeadr,tu ilcartlhya stt ep K valusehso ulredp lacK.:e int heK supplmyo del. v ACKNOWLEDGEMEN TS Iw oullidtk oee xepsrmsy s ienrcteh angkrsa,t iatnaudpd epecr iattioto hfneo llowing peopfloterh eciorrnbi tuttioowna rdcso metpthlieoo ftn h tihse sis. Mys upesrovrDisrs,l. H .K ikrmanP,. EG.rHe.g gA,. cH..R obearntsRd . WT.i llman frot ehivra lugaubildeea .Tn hcanyokfu o yro utri mpea,t iaennedcn euc roagement. Altlh pea satnp dr esesnttai fnf the DoefSp aorSitclmi eennIwtc o eud.l l ietk ot ake this onpiytpt oot rhtauinnkp ,a rtiDcrusNl..a SBr.o, l aM.nJ,H. e dlaenyd, B Aas.k er alolfw howme rree atdody i usscasn fdro wasrodu cnrdi toifct ihrseseem a rch presehnetreed. DrA..S .P almehre lfpoiirnn gcs loaicslas tiifiDorRn.., CW .a llfaroci ed eynitnigf primmainreyr aalnDsdr, S. .S aggfaorrrse iKn a nalysis. Thde epar'tstmc eehnntisctaahlfe fa,db eyLd a nCcuer riisae c,k nowlIew dogueldd. litkoe tMhiaknBeker thteoarnn Adn nWee sfto prr enpagr isdoimgaer aimnst his theasniMsda, l coBlomaf gro h ipsr oroaefd ing. DeniasneNd i cofrolt ah efirri ein.pd sh Almly f lelopwo stgartaefrods u tfhrieneidrs hip. The rtiFeliazenLrdi mRee sehaC recrneta nd Utnheierv sGirtaynC tosm mttiferoe fnudimnygs tudy. Katy andLe tuM sin keevf.eo rr gedta yotsfth heae l terntaetcail vueb . Lee, RosHieen,ra ynJ do hantt hDey naRsetsyt a.uT rhaefniirtre nddsuhirinmpgy et im att hDey nsatwya isn valuable. Yi My mothanedr b rothienIr nsd ianad, m yb rothienUr .Ss. Th ank youf oyro ur strengbtlhe,s sainndsg usp port. FinaIlw loyu lldi ktoe t ankh myf ami-mlyyw ifCeh,a ithanandym ay,so n,Th eja - for lookinmge s atfeatdefrad sutrlimyny gl asftew y earso fs tduy;e speciayloluy, Chaithafnoyyrao ,uh a vbee etnh rosuogm hu cshi nycoeu arrri vailn N ewZeal and . Ic anntohta ynokue nough. Thitsh eissid se dictaomt yedl aftaet ahnebrde lomvoetdh er. GLOSSARY OF TERMS USED IN THIST HE SIS K GENERALT ERMS Structural Stronbgolnyd Ke d int hec rysstatlrut curoef K minerIaitls vs a.r iocuaslllmyie nde raKl,n ative ineKr,tm atrKi,xo ru nweathered K, K. FixeKd K preseinntt h wee dg(ew -s)t,e( ps -c)r,a ck (c-a)n,di nter(lia-py)oe sri toifow nesa thered micacmeionuesra analdms o rphcoluasy s. Non-exchaKn (gsetarubclKte up rlauflsI xKe)d. Also kansK.:o winnN ewZe aland. Kp resenotnp lan(apra- n)ed d g(ee p-o)s itoifo ns claysK saonrdb aeted x chasnigteoe nso rganic matter. K ins osioll ution. Available TheK takeupnb yp lanotrKs extrabcyt ed K chemimceatlh otdhsaa ti mt om imiucp take by plants. K avaaiblility Refleacc tosm ploefix n terdespeonaidnlepd nl ta nt procestsehsare tl eatseh Ke thaitst akuepnb y planItst. d iifsfi tcouq luta ntify. K releapsoiwnegr (Kr elseea) ReleoafKs ef ro�m/ reservfeo rtmoK eaxn �d forms. Anyc hmeicamle thotdh adte terminteost al "availabilsaem easoufreK releasipnogw er. K" Kerxe leapsoiwnegr (Kur elease) Ke xtrabcyct heedm imceatlh othdamtse assuorie l � andK efxo rmes. gN.H,4 0Ac-QKTuK,( also NH40Ac-extraCcatCa1b2l-reKe)esK,xi e tnt c. KlILxr eleaspiownegr (KlILrxe lease) K extrabcyt edc hemical metthoo ds believed measusroe�i xl ofd iffesreonltu bei.lngii,ttri yc aciKd ( HN03-Kr)e,sK i ent c. Kepxl uKslIL x releapsoiwnegr K extrabcyct heedm imcealt hotdhsma te assuoriel Keaxn dK uexe .gH,N 03-(Ka cid-extK)r,a ctable NaTPKB e tc. K fixation ReveorfseK release. Iti st hpeh enomebnywo hni cthh" ea vailable K" becomuensa vaidluaebt lofie x atiboync lay mineraanldcs a nn ot easileyx trabcyt ed be methoudsset doa sse"Ksexsr elease." K spuplyipnogw er (Ks upply) SuppolfyK top lantAnsy.b iolomgeithcoadl e.gar. y,e gproattsr sit ahlda,et t erm"iavnaeisl able K"i sa m easourefK supplpyoiwnegr . Kexs upplypionwge r (Kesxup pLy) TotKa ulp tamkien u�se xu ptake. K"�sxpu plyipnogw er (KMXs upply) Knexu ptake calctuoltaKat ulep dt amfkireno ums failnlN H40Aecx tracKte.ax ble K losses Thep rediacmtoeudon ftK losftr oam farming systbeylm e achpirnogd,reu mcotv eatlc . SoiKl s puply (SoKi lg ain) Thep rediacmtoeudon ftt otKa slu ppltioae d farmsiynsgt Ietmc o.n stistouKitelsex us p palnyd soiKl..e xs uppbluytm, a yorm ayn oti nclude fertiKl diezpeern odnit nhgce o ntienwx hti cthh e terimsu sed. TERMS USED WHILE REFERRINGT O THE METHODS THAT DETERMINEK RELEASINGP OWER K extrabcybt oeidl HiNn0g3 I•t am easuoref is difficsuolltulsbyol ie�l e x.I ti sa nalogous to constraantte K. K extrabcyat memdo niaucme t(aNtHe4 0AIct) . eitmheears usreosKi elp xl u�s o rK eaxl one. ThreshoKl lde vel CirtiKc caoln creaontntii nt heeq ubirlaitseodi l solubteilowonhw i Kc rhe lefoarmseK ..exs ocuers iisn itteida. SolountK i K mearseuidne qluiibr0a.t0Me1 Cd a Cslou2lt ion. Kd esoribnCea dCs lo2l uptliKuoe snx tracted with NH40.A c K-Caac tiviitney q urbiarltaiitsoeos dio ll ution. Gapocno ns.tT ahnigtsi vaem se aeso ufrr elative titgnheosfsb indoifnK g+i nr elattoio othne r cations. QTK QuitcekKs .tT himse ausersa pproxi8m0%a tely of thKec pxsl ou�i.sl NaTPBK K extracbtyse odd itueamtp rhebnoyrl(o Nna TPB) reagTenhtir.se agmeenats usreosKi clax n �dx . ResiKn K exrtactbeyad m iexdc atianodn a nireosni n memrbanIen.C hpate6ir w ta suse dt om easure soKixclp lu�.s Acid-extrKa ctable K exrtactbeybd o ilwiint1gh MH N03I•ti sa meaeso ufrs oKiclax n eda ssiollyu fbarlcet oifo n so�ixl. Step K A meaes urof� xs oobitla biyn eddt ihfreefen ce betwaeceindt -rtaeacxblaen KdKc rI itst heorerfe ac ompeudv talue. QSK Quicskte Kp. Thiissa measoufres oi�l obtabiynt ehdedif refenbceet waeceind r-aecxttable K anQdT K.I tis aac lospmoue tdv alue. OTHERS •• SignificaatPn <t 0 .05 • SignificaatPn <t 0 .01 Least-sdqfiufareerse nce LSD Nosni gnificant NS Coefficioefvn arti ation c.v