rc potassium and ammonium a fixation in indian soils

3 ab rc Potassium and Ammonium CI a Fixation in Indian Soils

(A Review)

Potassium and Ammonium Fixation in Indian Soils

(A Review)

1. 6. GRWAL AND J. 8. WAR

F u r t u z ~ ~ i b Ihc king-pn olngricullun, and its intenstve and halanad ua is the only way lor providrng f d and clo~hiny to ~ h c cvcr growing human populatiun. But fertilizer\ being prvduclr ctf the rndustry are costly in- putr, pniculnrly in counare\ lrhc India. I t rr wcll known that Indian wi l t arc crtrcmell delictent tn nllrogcn und ~t 15 unthinkable to habe ~ I I+ furlory yicldr o l crop ntthoul thc ux of nmognou\ fcrtrl~acrc. Ammo- niscal fcr t i l i~ tn are the cl~ort icnportanl. Thc I~IS of nrlrogen through bching and volatrii~iitron put\ a scriou\ lrmita!ron on the economy of nkro- &nous f c f l i l i r r~ . Thc phcrlumenon of nrnmonra fixstron in bits Ilar both psil ive and ncytive itspet\ frum the p i n t of view crC effici*c) of nitro- *nous kflrl~m. I n thrl hullctrr~, i ~ n alltmpt has hccn nradrh revrcw the work d<me on ummoniu lirutron in Indran \orli and rts pructrraE)mplicatrons.

Nenl to nrtrogcn in i n lpwncc arc phaaphat~c and puuyc fertilrrerc. Thc phenomenon or phmphrlc lixrtron has k r n dircuircd h i the authors i n unothtr bulltlin publrrhed h! the I.C.A.K. In the p e n t huilebn, however, the situat~un urth npnrd to p las ium li.\alron llaa hren rebrcwed wh~ch is impomnt for Indrcln bttualions becnuv almost all'thc potisssic fcrtilrrers a n imported, and hcncc urc coslly 1npu13. %con%, the miyor ngriculturd soils groups bcirlp ullu\rul, with IIIIIC 1)pc of clr) m~ncrali, the polasrium lixnlion bcxomn a rrlous prablcm. 11 ha, r lot (IT practicctl implications. 'fhnc problrnlr, a, the) relate lo the Indictn s o l , have been discussed in chis bulletrn.

June 4. 1973 I. S. GRLWAL and J. S. KANWAR

Prefaa

SECTION 1

POTASSIUM FIXATION

1. Introduction

2. Pokssium Status in Indian Soils md ib Dwipion

3. Mechanism of Polassium Fixation in Soih and their Potassium Fixation Capacity

4. Facton nfecting Potasrim Fixation in Soils

5. Relea% of Fixed Polassium in Soils

6. Practial Significana of Potassium Fixation in Soil$ . .

AMMONIUM FIXATION

8. Ammoniaal Nitrogen Status in Indian Soils aad its De,. cnption

9. Mechanism of Ammonium Fixation in Soils und thcir Ammonium Fiation Capacity

10. Factors afecting Ammonium Fixation in Soils

I I . Release of Fixed Ammonium in Soils

12. Practical Signitkana t w i u r n Fiulidn in Soih . .

SECTION I

POTASSIUM FIXATION

THF phenomenon of pota~sium tisition in soils and clay n~incrnlv in well ntablished. Polubbium being one of the rnujor plunt nutrient$, its Ranlion in soils und clay mineriklr h:~c hren invcstipted from theoretical as well ~1

practical pints of biew throughout the world for over a century. Thc vubt literature on pot;~trium fixation in wllr rignific~ not only the importana of pota\sium lo pk~nts but illso thc dillicultici that arc k i n g cncounterd in intcrpretinp it\ prfi~rmancr in the roils. This is undcrstandublt whcn one consider, the prevalence of polsrrium mincralr in soils, its readily soluble nature and fixation in coils. .

Po~aairrtn Fi.ru/i(m. The.tcrm potas~ium fixation has k e n defined ar a proms, of cnnvert~ng exchangeable or water solublc potassium to modcrutcly nvi~ihhle potarsium which i c con$idered fi~cd. This definition of potastium fixation it dependent on thc tvpe of thc crop find the time fnctor. It is more prccite to define the lixc I potarsium ns applied potarsium which is not immediately replaad by neutral normal ammonium acetale solution. This definition brings the phenomenon of poletiurn fixalion into a more contirlcnt relationship to the r c l c a ~ of non-exchilnpble potassium, both nativc and fixed.

As early as 1887, the German tcientist Kcllncr observed that a Japanese mil whcn leached with dilute potassium hydroxide solution strongly fined p~ta~sium, which could not he removed with hailing norm1 hydrochloric acid. Dyer (1894) and Frear and Erb (1918) cdculated from crop balilncts of long-term field experiments that a greater part of the applied potassium W.IS llnavailable to the crops. Thic was supposed to hc fixed. Volk (1933-34) studied this phenomenon in detail and rtportul that there were a number of factors which dc~ermined the potas4um fixation in soil^ The most important ones of these arc nalure and amoud of clay minerals prcxnt, pH, exchangeable cations. potassium conantntion, wetting and drying, time for fixation and the amount and nature of the salts pment in the soils.

The clay minerals chieRy responsible for the fixation of pta~siurn are of the expanding types such as illite, montmorillonite and vermiculite. The mechanism that has bca considered Lo be active in this process, is the triipp in? of potassium ions between the lattice unils sheets of the enpandinglaflias when the% arc treated with solujle potassium. Some of the clays such as iliite can fix the placsium under moist conditions and others such nr montmorillonite can fix appreciable amoune of potassium only on drying ria

drying help in contracting tbe lattias.

The fixation of applid potassium in soils and Lhc rekaoc of the soil potarsium for utilisation by plants or its extradon rith various oalt solu.

ticlns dcpndr to a large eltent on the amount nfdlfcrcnt form\ of the pota- u5ium prrwnt in the soil. Thc nature and the form of the potassium prrrnt in a ,oil movtly dcpnd upon the minerals composition of thc soil, leachine. dcgm of weathering und the mcchaniwl composition of the wil. A knowledge rtpnrding the vilriou\ forma o i thc potar\ium in a toil and nn underu(:tnd~ng of conditlonr conlrollinp its availnhil~ty to prowlnp sops IS

imptrrtnnt for thc nppralbal of the ;cvailahlc potas~lum in thc soil. Accord- inp to rllc curmat r i ru thc u~i;tvailshle formr of potnrrium anount for 90 to 98 per nnt, the rlowl) ;~vaili~blc h rm I to 10 p r cent and rsedily availahlc farm I to ? pcr cent of the totill roil pcllassium. Since lhe\e formr of potac- \ium in wilr cxirt in quilihrium will) one nnnthcr and n dqplelion:ol' one form i c rtplrni\hcd by one or more other forms, it is impemlive lo have a Lnowlcdp of 1111 ~ h c form\ ofthe pcitnrsium and their rate ofrelc~\e for the sppraisd of p)tnt\ium rupplying power of the soil. I t is well known to ~ h c i~priculturirt\ and \oil rc~cntirtr that many soilr cclntainingjnrge ilmounts of total potilrrium rc\pc>nd m;~rbcdlk to an ilddition of thc pJLI~sium fcrtili- rer. Thw ir due to the \low release rate of the unava~lilhlc @rmr o I potcl* rium to thc avsilnhlc form\ of potnsrium.

Rahcja or 01. (IPSR) concluded from the simplc fcrtilizcr trials conduckd on cultivalon' lieldr In vsriou\ stater of India that then was a need to apply pnln\riun~ over und ilhovc Ihc optimum dose$ of nitrogen and phosphate to incnarc pri?Rr ill the present rate of fertililation ofthc vnrioun crops. Kan- war (1970) rcportcd that plmsrium deficiency was fairly widespread in India und was k i n g aggravated by using high-yielding varieties and un- halnnced u u of fcnil~~ers. He stretccd the use of balanad Rrtil~zericontain- inp nitrogen. pholphorus and potaoium in a strntegy of intensive cropping with high-yielding varieties. The problem of polassium manuring of crops ix mthcr II complcr one, rtquiring a comct understanding of the various soils and other factors which nlFcct the fixation and availability of potassium in diCnnt typs of soils.

Man) potassiumdcficicnt soils show a poor rrsponx to potash fertilizer. This phenomenon is causcd hy the potassium fixation in the soil material or other tacton. I t i s of great interest to know the potassium fixation in soils and ~ h c extent to which thc potassium M fixed is available to the plants so as to work out the optimum do* of potassium for various mops in diKe rmt typs, or soils.

The r~ud ia n r r i d out hy Pathnk (1954), Mehla and Shah (1956a, b and c), Mitm r r 01. (1958). Pathak and Srivastava (1963). Gnwal and Kanwar ( I W 7 a . b and c). hashad rt 01. (1970) and Mchmlra and Singh (1970J, ind i ted that Indian soils could fix conoiderable amounts of potassium which Was not easily availabk to plants. Brief nviews on potassium fixation in soils am gien by Rarnammrthy EI 01. (1952), Wiklandu (IPS),

R)TAS(IUM AN11 AMMONlIlM FIXATION IN INDIAN SO115 3

SchulTelen and M ~ r e l (1955) and Apnrwfll ( I W ) , Rcitcmicr 11951) h ~ s p m n l c d a review on soil potas~ium.

The purpose of this review is to hrinp up lo date and erumlnc crilicrlly the research done on the potassium fixatinn in Indian soils, lo idenlily thc @iy in the knowledge and ~upgmt futun linm of work.

2. POTASSIUM STATUS IN INDIAN SOILS AND In DE'jCRIlTION

RIIAEYILIM I! cnn~idcred the most abundant in soils particularly in alluvial uril%, ur comprml to c~thcr plant nutr~cnls. The range o l ' t ~ a l potartium In ur~l\ is ennnous and i t depends on the mineral composition of the parenl m;~~crirl, le:~ch~n~, type and dqree of wathering and the mechaniccil com- (x,sil~on of the \oil\, The hchuviour of potassium in the u)ils i s rillher complcr. Itr 5oluhillty range$ from ea'iily snluhlc form to inoluble forms, ~ucl l as prim~lry ant1 secondary mineral$. The snit polascium @n tx divided inti, four categctrlc\ vu., wlublr polr%ium. cxchanpeable hassium, lixed pl:1\\1um and I;~llicc pntnssium.

Snl~rblr kru\vi~cm. The potns~ium existing at any one Imc dirsolved in HII~C~ of a roll under field mo is tu~ conditions and relatkely unhnund hy ccrtrin e~c11;lnpe forcts. i s considered as soluble potassiud Its concen- tratlon vurie, &really from $011 lo soil and also in the same sdl on dilkren~ nccclclons, depnding on the vvcral factorb, such as the amou4 of adsorbcd potassium, the water content or the soil, kind and concentTion of other lonr present and it, adsorption hy plants. The soluble pota16ium is easily ~~vailahle to plant\ hut quantitatively it in not considcred important owing to its smn1I ilmounts.

Exchan~rahk Pomssiri~. The potassium which is aboorbed on rhc roil mrtcrial and ic replaceable with normal neutral salt solution, is considered cxchanpeahle potassium. The content of exchangeable pblassium depends on factora, such as the mineral composition ofthe exchange material, roil texture, water content, weatherin@ and leaching conditions, lertilization. liming, kind and canantration of the competing cations, ctc. The content or the exchangeahlc potassium in mineral soils is usually less than one per an t of the total potassium. In sandy soils, the exchangeable potassium is usually less than the heavy roils owing to bs weathering, lower exchange cnpocilg and more Iachinp. The txchangeable potassium is considered compktel!. nvailahle to plants either directly by MntaCl exchange or iltdirmly h) chansin~ into the soluble pomsium.

Fixed Portlrfiu,~. I f potassium added to n soil is so firmly bound that it i s not immedialely replaccable with ncutrnl ralt solution it is wid to bc fixed. Thc fined p a s i u m is onen included with the lattice potassium in the category of non-exchangcabk potassium. The fixed potassium re- pments actually a naturnl transitional sta@ k t w m the eachangcsble poussium and Ihc lattice potassium from wh i i it is difficult to distinguish it shaqdy.

Ldtin Polaim. The major portion of the tohl potasium in most mineral sob resides in the potasiwn kuing primary pad clay m i m b in

..IrA. UM ANV AMMN, JM t l U 1 1 0 N IN IkdAN WILE I

non-errchangeable form. The primary minerah ere mulcavite, blorilc llnd ptass~um fcldsp?rs. In theclay onl) lllitc ha\ auln~andal pobrriuni conlccn. The Ii~tticc potassium is made :lvailable to plunto by wcclthering ant1 thc nmount releaxd depend5 upon \oil texlure and environmenti~l cond~~~o~ i r .

Gcnemlly, the various forms of soil potas%ium u n rtlilted and comprije u bystem in which an increa\e in one form nccun at the expifinre of onc or more olher forms and in which thc net movcmcnt may (wur from Icrs av;lllnble to highly available states or the revere, depending upon the particular stress. The nvailuhil~ty to plnntr depends on thc um~unt tcnd relativc mob~lity of the d~ffercnt forms including the rate of rcplcnirlinie~it of dcpleterl through immediately available form by rescrvc supply. Thus the dillerent potas\ium fraction\ art.conridcreJ the chemlwl I~~ INI or thc potas\ium reserver, potar$ium rupplying power, itr liutlon ant1 ;~vailnhll~ty in soils. Reitemier (1951) has discussed thed~tTercnt forms o l ' w ~ l potarrlum :ind thcir availabll~ty to plant$. Raychaudhuri and Datva (1964) hriefl) reviewed the potassium status of Indian soils.

Foml uri(l Avuiluhle Poturri~im in Indian .SOB. Ukll and I>C~;II ( 1114.4) complled a map of India, rhowing the dlrtribution of total ptursium dl\- trict-wire which indicate\ that the districts particularly of 0omh;ly i~nd Madrar derived from D e a n trap and crystallins gneiss lends to hnvc lowtr d u e for total potarsium. Out of [he 137 dirtr1d;c from which the data war compiled. 17 district$, namely, Darjeeling, Jalpsiguri. Rajshahi. 24-l'arga. na\, le+sorc, Pnlamau, Angul, Lucknow. B a d , Parbhani. Ni?amab;~d. Medal;, Atrufi. Balda, Raichur, Warangal, Kurimnngar and Karhmlr north had value\ of total K,O grater than 1.0 per ccnl ~n sod, while 26 dlrtr~cfr, namely, Chittoor. Chingleput, South Arwt, Salem, Madura, Tanjorc, Ramnad. South Kanara. ~alabar, Broach. Surnt, Sholapur, Bljapur, Ralsg'lat, Rewa-Umari. Baroda, Navasuri. Jalrum, Hamirpur, Ilarriing, Sylhet. Ballatsore, Coorg, Amnli and Mehwnr had values less than 0.3 per K1O in their soils. Thus potassium deficiency could be mmt probable ~n the lalter group.

Oommcn (1959) prepared two maps, one on total potusium (HCI enmctablc) and the other for available potassium (Morgan's exlracknt) of dimerent plaas of India. The total polasrium of almmt all placer sludlcd by him was high, i.e. 3,722 kg K@ per ha and available K,O was low lo medium, i.e. below 112 kg K,O per ha to 280 kg per ha. Ramamoonhy and Bajaj (1969) pnplnd a map of available polassium on the result$ of mils testing services for 198 districts. They indicatad that thc soih in 36 districts are low, in 110 districts medium, and in SO districts high in thic nutrient. The soils of Gujanl. Kcnla, Orirsa, Tripura and Coahtal anas of Mahanshtn a n classified into low category with mpea (o the svaila. bility of potassium. The mils medium in this nutricDt a n mainly in Bihar, Havana, Myson, Rajastban, West Beaspl, Dclhi and Himaohal Pmdcsh.

R 1. I. GRFWAL AND I. 3. KANWAR

The rt~ilr of Madhya Pradnh and M~harrvhtra are generally medium or high in available palusrium.

Rumumwrthy rr ul. (1952) studied the availability of potash in Indian soilr in relation to geological origin of the soils, pH, total and available K,O

(available K,O x 100) and the pcrcentnp availability, Total K,O .

Thcy arc ofthe opinion that geological origin of the soil along with other l i i a t ~ r ~ urc rcspontible for great differences in potassium availahilities. Gi~np~~cnlluvium and the toils bordering thevindhyan system have generally low potnaium avuilability or hiph ptasrium lixation capaciw. The toil of the cry\ti~llinc gncirs or cnarhll alluvium bordering netaceow or the Oond- wnna \y\tcm hns hiph availability or low potassium fixatioi capacity.

Form qfpturtium in Indim soilr. Considerable attenti4 is being paid to thc d~ffercnt form\ of pc~tasrium in Indian soils to undcntpd the potan- ium rupply~ag pwer of the soils and the fixation of the a p p N potassium. The lnlirrmntion :~vailublc on thic aspcct is presented to proPIde the logical hilois to understand the hchuviour of potassium in these sdls.

Scn rr a/. (1949) was the lint to determine the different f m s of ptassium in 20 rcd and latcrite soils collected from various parts ~f India. The cxchangel~hlr potassium ranged from 1.56 to 33.32 mg with an average value 01'8.55 mg per IW g of soil, which is considered low. The citric acid soluble potasrium r a n d from 1.38 to 30.26 mg with an average value of 6.43 mg p r IM) g of soil. The exchangeable and citric acid wluble formt of poltlssium in the soils examined showed a correlation eo-efiient of r - 0.98. The hydrochloric acid soluble potassium ranged fmm 20 to SO3 mp w~th an average vuluc or242 mg per l W g of soil which i c rather low. The cxchanpnhlc potassium was 1.3 to 11.3 per an t with an avenge value 014.8 per cent of the total exchangeable cations in these soils and it generally increud with the depth or the profile in laterite soils.

Pwtjub. Harp~na ond Himocha/ Pradesh. Kanwar (1959. 1961) ported that clay minerals of normal Punjab soils contained 2.80 lo 3.86 per an t of total K.0 with a mean value of 3.31 per ant. The clay minerals crf Mine alkat~ $oils of Punjab contained 3.54 to 5.50 per an t K,O with a mean value of 4.64 pcr ant. From X-ray deferential thermal analysis, er- change Capl~cily, potassium magnesium content and other chemical alwlysis, he found that the dominant clay mineral in Punjab soils war illite with some chlorite. nKsc clay minerals are known for the high potassium fixation cawcity and thus can eRcd the availability of potassium in these soils.

Grew111 and Kanwar (1966a and b) n u d i the d i R m t forms of potassium in 2.3 fepfCmlatiw wface soil samples c o l W from diRmnt soil zones o f Punjab. The range and mcla vdus 01 the d i h t forms of potassium is gim in Table I.

TABLE 1. DIPER~NV bORMS Ok POTASSIUM IN PUNJAB - .

Raw Avura$~ Potuuruni Fract~onr -

mnlK,O/lmo

The Punjab so~ls are well aupplicd wilh total plasrium. Ncarly 30 p r cent of the told plassium war prnent in the HCI ,olublc Corm, 6.1 p r cent in the fixed form, 0.98 F r ccnt in the watm ~l lublc und exchangedhk form\ and 0.93 pcr cent in the available form. Thcrc was highly yipnilicnnt prltlvc cornlation between ditercnt forms of potilaium ddermincd in this aludy as is indicated in Table 2 and Figs. I. 2, 3, and 4.

Av.ill- Pjtarsium Iracuon hhnnic. ubk Flwd zibk Total ,,,,

Walcr roluk 0-82 0.M) 0.30 0.111 0.76 Elchangwbk 0.73 0.47 0.25 0.93

Fimcd 0.77 0.39 0.56

HCI wlubk 0.13 0.32

This indicates that there exists an equilibrium betwan different form of potashiurn in thcse roils. The exchangeable potassium was 1.4 lo 7.72 per cent with a mean value of 4.69 pcr aat of thr ation exchnngc capacity of there soils.

Kanwar and Grewal (l%6a) studied the d i f f m t fractions of potpsiurn in day, silt and fine sand fraction of the reprwntative surlacc soils of Rmiab. The rangc and the aversge values are gvm in Table 3.

10 I 5. GRCWAI. AYD I . S. KANWAR

cxcww ~or~s%w mq /looq

Q ~ u . I . R o l ~ ~ l o l ~ l ~ i ~ klwn walcr mlublr and uchanye;lblcpot~em ar~lr

WTASUUM AND AMMONIUM FIXATION IN INlllAN XNU 11

v 400 boo 100 loo0

I:ly. 3. Rrlalion?h~p betwsn fired un4 llCl wlubk polavlum in wllr

Clay , , 5 to 4 2 1.65 S~lt .. 1.11010244 2.15 PIW und .. 0.95 lo lA2 1.21

Clay . . 1.45 lo 2.15 1.75 Silt . . 0.61 lo 0.85 0.65 Fine rrnd . . 0.16 10 026 0.21

N x r d (I NHNO,) K,O%

Clay . . 0.28 to 085 0.9 5111 . . O m lo 0.16 0.11 Fiw sand .. 0.01 lo O M On

Thc matcut of these form of p W u m M a negative sipififant codation witb Lhc sk of the soil partida. Tbe clay fnclion of the coils on an a v m g mtributcd 36.3, 52.6 and 12.8 per mt of tbc (otJl, HCI dubk wid Bned potaIsium mpedivdy.

12 1. 5. (rllliWA1 AND 1. 6. KANWAR

Pig, 4. Rclrtlonhip betwwn HCI soluMc md lou l potassiumin wils

Khanna nnd Prnhnrh (1970) btudicd the putassium status o l 75 soil simpla of I3 profile\ ul Hisur distric~ (Haryanu). The rdnp and average value or JiLrrnt Craa~ons arc given in Table 4.

TABLL 4. U l r t w r s r WMS ut WIWUI IN HISSAR (HARYANA) WIS - . -- . . . . .. . . . - - - . . - . .. . - . - - .- - .- -. -. . .- - . .- .

Pa~nauurn frucl~un~ Ranat Annrc . -..--

(rn.c. p r a a t )

HCI wlubk . . 4.29 lo 22.5 11.39 Crcbangmbk . 0 to I 0.42 WUI?~ SOIUM~ . . 0.025 10 0.25

- -.- -

The wwaler soluble potassium bad a positive significant combtion (rzO.574) with exchanpbk potassium which had a positin coneltion (r~0.517) with HCI rolublc potassium, indicating an equilibrium bwccn rhcu rhm forms of polarsium in t k soib. Thc HCI solublc potaorium had (I significant positive cornlsrion (1-0.748) with silt + day and thc

POIN OM AND AMMONIUM FIXATION IN INDIAN KUU 1)

exchangeable po(clrsium s h o d a siyifwanl prnitive wnr l r t i on (r 0.022) with clay content o f thsu soils.

Uffar Pnrdrrh. Mirhru cr ul. (1970) rcpunni d~llerenl f o r m o f potu\\- turn in 24 rcpmntr t ive wilr o f I8 doirias o f U t u r Prnde~h. Thc rangu and mcan value arc p e n In Trlblc 5.

Forms d Pc>~sw~um bn8c Amru#! . - . . . - - - . ..

Water wluhk . . 0.82 lo 7.53 2 3 I~tchanpcahle 7.49 10 75.66 21.0 Rud . 41.V lo 2Yb.7 119.2 HCI wlubk . . . UI.0 to W.0 546 0

Alluvial mils wrc compnrativcly rich ~n water wluble and HCl solulrlc pu~ursiurn, whercus the Vindhyan 5011s had morc poluvriurn in cxchilngcnhlc and fixed lcirms than thwc o f alluv~ul, Tarui and Bundclkhfid rcgiol,,. Mlsra and Shanknr (1970) rcporlcd that sot1 wmpks from vurieus m ~ l zunc, or Uttar Pradcsh on an average conhllncd 1.74 per ccnl K,O. Ncurly 6. I w r ccnl of !he total potawum was prcxnl In the fixed form and 0.77 l x r cent in thc cxchanyablc k)rm. The mean wutcr soluble powarlum con~ctlt of the* soil\ wJr 2.6 ppm. The dlstrihution of (bhe form, ol' phssiurn in vdriou\ 9011 Lone\ 15 given In Table 6.

Alluvial d l s (Central rsion)

Hill oils 1,654 129.6 IM.2 15.1 0.B 3.00

Slgnlficant pou~ i \ c correlation> were r h n d between rhc various forms of soil potassium dctcrm~ncd. They i nd i c t i l l tllat mutt o f thc Utcilr Pnldnh toll, poshes \uliir.~enl amounts o f potaa%ium l o m e t the demands of growing crop. Mchro ln and Slngh (1970) r cpo r l d l a t the \urfarr boil wmplsr of b r ~ s d roll g roup ol' l i t tar Prndcbh conca~ned on an avenge 2.29 pcr cmt of calrl pl l r \r lurn. Approximately hl.YS. 31.06. 6.19, 0.69 und 6.1 1x1 cent of the tocrl pitass~um waa prescnl as lattice, HCI $olublc, lixcd, txcl~angcahlc i ~ n d Hater \olublc pohr$rum rcrpnively. The mran vnlue o f dilkrcnt h r m ? ol' p)tilr>tum in dln'crenl so11 grwps is glvcn in Table 7.

I'i~.trc-yru~nr.d bbckv,~l . . 2.4 I$ I l h 743 1.470 2.415 ( I I I , 2.3 12 I?? 571 1,602 2,:16 Hr~,cnt r l I ! ~ \ l ~m~ C n r 1 1 1 l . 2 .8 IX 124 7% 1.441 2.116 Old u lhut~t rn

Thc dit~crcnt form, of pntaolum had sipnlliuant poritlve hrrelntions with ach other (Table 8).

T A ~ L L 8. ~~wIRII.ATIOS COCII.FICIENT ULTWElN \.ARIOlIS CORMS I* RITWUM IN SOllS

... .................

Poluslium fructwnr Clchmp Fixed HCI Laltlca Total ;~hlr Solublc

Water wlubk . 0.64 0.26 0.59 0.57 0.62 . . . . F~chariwbk 0.53 0.48 0.34 0.44

Fired . . , , . . 0.62 0.42 0 .9 HCI soluble . , .. . . 0.73 0.94 Laclice . . . . .. 0.99

s Jlh UM AND AMHOSlUM PIXAIION IN INDIAN XIIIS I !

Bihrr. Mukcrje (1955) rcporld the diflerenr forms of putur~lua~ in rcprcentat~vc surfice roil of B~har. Thc rangc and incrugc valuer ilrc glvcn In Table 9.

TABLE 9. FORMS UI IUIAS5lUM IH ~ I I+AR W I S

T~u.lrl ipr 01. (19671 repurtcd diLrcnl form\ofpu~urrium In wil \,~mplc* lronl hotlr \cdcntilry and alluvul roll groupr of Bih.tr.

In HhO, roluble, non.e%changc;~blc or fixed, cschanye~hls end 0.01 N calc~um chloride roluhlc potar5ium Iructlonc o l thex wilr on an rvcrilpc e)mpr~*ed 5.8 . 5.3, 0.45 and 0.2 per an1 of tocnl potassium. Kanke, ('II,I:- bara. (jir~dih. Putid2 soil, conuined low amounU of fixed potassium wlille Arar~a. Katihar and Suharsa \oil$ conlilincd high amllunlr of non-exchunpca- ble or lixcd prila>slum. The correlation coelfkienu ohrrvcd beluecn difirent forms of pora,3tum are given in Table 11.

TABLE 11. CORRLLAIIUS COtFFlCILEiT BLTWlN VARIOUS bW15 01

FUIASSIUM IN D l l M SOUS - .. . - . - - . - -- - . - -. . - . . .. .- . . . -.

Pousium lraiUons Exdmgc. Non INHNO, O.OIN Toul abk crcbmw- wlubk CsCl

a k wlubk

I6 1. S. GllEWAL AND 1. I. KINWAR

Ornerally alluvial wils of north Bihar a n richer than sedentary soils in total powsium. On the baris of thc amount of total and txchangeabk potarnium mat of the Bihar wils may be wnsidend as well supplied with ovailablepotausium. Prawd rral. (1%7a, b) reported that 14 soil sampla repreanling wilr of differen1 geological ori~inr of Bihar, varied in their contents of total and normal nitric acid soluble powsium, The potasrium varied from 1.09 to 5.24 p r cent K,O with an average value of 2.99 p r cent. Normal nitric acid soluble potassium varied from 0.059 to 0.351 per cent with II mean value of 0.183 jxr cent (Table 12).

T A ~ L ~ 12. AVERAGE VALUU Of TOTAL AND NITRIC ~ C I D SOLUBE

MTA.9SIUM IN L)IFFERENT FRACTIONS OP BIHM/+DILS - .- - . . -. - - - - -. -- . -- ....a. - -

Soil fructivns Taw1 K.0:: IN H* S O I U ~ I ~ qd:. - --. -. -- ---;---

Coaw und . . 0.25 0.W$ Finc a n d . . 1.17 O.M$ Slll . . I .ox 0.004 Clay . . 0.53 0.23.!

/

Sand and silt fractions contributed towards total pohssiun more than the dny whereps clay conlributed relatively higher in nitric acid soluble poless- ium. Fine sand fraction 01 almost all the soils contained quarlz, feldspars and mica in thc order of predominance. Kaolinite was the predominant chy mined followed by illite in sntentary soil whilc the alluvial soils contained illilc as the most dominant clay mineral followed by kaolinile.

R&sthan. Dhawan cr 01. (1968) reponcd the potassium status of the broad soil groups of Rnjrsthan. The average vducs an given in Table 13.

form 01 potnanrum Range Average

(GO W/IW I) - -- - - -- -- - - - -. -- .

Toul .. 187 to WIO.5 806.1 Wanr wlubk .. 0.15 lo 4.75 1.7 WamMc . . 10.0 to 38.5 20.7 N c i w A l a w b k . . B.O to lW.0 97.6

Them is a widespreud variation in the tokl potassium wntcnt of d8e- rent soils probPMy due lo ditfcnnoa in Ihe parent material. Medium black roils of Jhalawarand Kots co + i .d t - n ~ * ' i - 7, 1 P-

MTMSIUM AND AMMONIUM FIXATION IN INDIAN 3MW 17

changeable potassium, probably due to their higher clay content. The water solublc and exchangeable ptassium on an average was 0.21 and 2.54 p r an t of the tala1 potsssium, mpalively. The non-exchangc~blc potassium accounts Tor 12.1 per cent of the (oh1 potassium and had a~high p i l i v e cormliltion coefficient (r. 0.57) with l v k l ptlrsium, The correlation between cxchanmbk, nonznchangcable and lotal ptas$ium indicured the polribility olwmc kind urquilibrium between thew li~rms ( ~ f polursium in Rajaslhan roils.

Swami and Lsl (19701 reporled that 29 rcprcunlative soil9 of Rnjasthn contain thc folluw~ng amounts oT difirent Torms or potwium (Table 14).

Ran@ Avern&e (m*, per cent)

Lodhn and Seth (1970) reported the amounls or total HCI soluble and lixd pohnium in ci&t hroad wil group of Rajasth~n. The rvcram valuer for dllfcrcnt wil group arc glven ~n IS.

- .- .. . -. . ---- ---.-

Soil groups HCI wlubk ,mg prr lm ,) Fi"d

Medium Msck wil Wium rod and Mack wil htcdium rod and yellow wlh Undifmtirlai

wit alluvium Gny brown loib Yehw brown wils Gmy bmva aoib of riwr buia Ibrrl urib Anryc

All the L~rm< ol pta\uum were more in undtlferentiated alluvium und gray hrr~wn hiril,. The clay of undiRercntia~cd alluvium and paray brawn \oil+ eontnind vcr). high amounts of total potassium i ~ n d the prc- dominun! type of clay uppeared to be illitc. The average valtrcr of tot;~l IiCI. \~rluhlc and lived v~ut\rium in clay, silt and \:lnd f r a c ~ i o ~ ~ \ of soil\ wcrr a\ uelcr:

('Id\ . . 2,457 1,335 41'1

S~ll 1.417 52 1 176

I'IIIC unct 754 ?hl 2T ---

The tolrl HCI \oluhlc and tired potnssium decrcaced with the increltre is thc \ i ~ c of ~ h c particlea. The conlrihrrlicrn of t~rl i i l potl$\~uin wa\ more hy ch)\ In c:~+e of medium hlnck solls, mrxed red soili and red and yelluu roils. Whilc in ciisc ol'undillercntiatcd alluvium, ycllnw hmwn, prey hroun and dcrcrt soils, tlic contribution was more b) sand particles rrhlch could hc duc In tllc ptirr\lum hetlrinp primary mincralr. On an avcmp in d i r e rent ( o ~ l proup\ the pcrccnlagc contrihulion hy clay, silt nml fine sand frac tion\ tou:lrd lutal HCI roluhlc ;ind 6xcd pcitas\lum was rs under :

Clar Sill Sand

. .. . . ~- Total polaulurn .. 36.1 19.0 35.6

I k lwbhk plnuium 43.0 15.3 32.5 Rw4 paladurn . . 60.3 18.0 10.1

Mdhw P r d s k . Vcrmo and Vcnna (1%8) rrponed that available (water soluble $ exchanphlc) potsariurn content of different soil proups of Madhjn Radcsh varied from 0.064 to 4.65 m.e. pu I00 8 of soil. The ranp and arrrag of available potsssium for diffmnt soil pups wcrc as under :

POThSSIUU iYI) AHI)YIUW FlYhllON I V IYDI4Y SOIW 1')

Allnt:11 . . 0 40 10 1.11 0 (h lkrp hl.ak . . 0 10 lo l 2 5 0 79 McJlam hlxL . . 0 IH IU 4.65 1.31 Sh;~lh,u black .. 0 2 9 In 3.0 n 88 Mned red ;tnd hl.trL . . t I I 3 . 0 1 02 Rcd ;an,! ~clhb~. . I I t o 2 0.117

On the h:~qi\ of the \oil proups the i~lluvisl \oils hhnwd the tm8llcd amount of ilrailahle pot:~\\~urn and the medium hluck the hipheut. T l ~ c available pol.~\rium had ll~gllly ignificunt po\ilivr correlation wit11 p l i In the rcrl :tnd ycllow soil.;, wilh c:~lcium t;~rhonatc in d n p hlack, ~ncd~um hlack and rcd :lnd yellow soil\ and w ~ l h orgnlc motlcr in he alluvial and mired red and h l x k ~11s .

(;~ijarur. Uehln and Shah (1956a, h and cl reportcd exchan~~b le and h!Jrtichlorlc acd u~luhlc pI;l\\lum In hS \urfua soil# o f Ahmedahad, Rarl~da. Rrooch. Kaira. Meh~ana. Rlnchmshah, Surnt and Suashtra (11s- tricti Thc cxchanpcahle pit:twurn v:iricd from 0 35 lo 1.M m.e. p r I W p or .KK to 1,515,759 kp pcr ha. The hydrochloric acid u~luhlc potasiiurn varied Trim 3.56 lo 12.51 m.e. per I(X) p or >,It.? to IO,Y3X.718 kg per ha. The degree of pot;~\+ium uturatlr!n on cxchanpc complex varied from 11.75 to 9.W per ccnl. In >oil prolilc\ crchanpc;~ble p~ta$c~um dccrca\cd with the depth of thc profile. The c\chungeahlc potu\!um ind~caled sufficiency of svailable p ~ t ~ > $ i u m for thc crop growth In thac ubil5.

Kuralu. Money (1959) reported the pol;larum <latuo o f Nanjanad wils. The total pntrr,lum ranged from 0.052 lo 0.461 per cent, with an average valuc o f 0.167 per cent. The eady ava~lablc polilrsium variul from traces to 0.22 p r cent with a mean valuc o f 0.0093 per cent. Thc available potactium comprised 046 to 17.6 p r a n t of Ihc t n ~ l plusriurn with a mean value of 8.4 percent. I t was concluded that available pntntsium was very low in these roils because the potassium bearing minerals were generally feldspars which did not liberate enough pntasrium.

TamN Nudu. Rajakkanna I,: 01. 11970) reported that the hlrck, red and alluvial wils o f fam i l Nadu contained an an avenge 1.07. 0.53 and 0.46 m, e. o f availahk (Exchangeable i. water soluhle) pntauium per 1GU g of aoil respectively. Thc available potassium was significantly and positively dated to pH values in the rod and alluvial $oils.

3. MECHANISM OF PO'IA!SIUM rrXAnON IN WIIS AND THEIR POTASSIUM FIXATION CAPACITY

Mrrhasim nfpmvrium fixation in soils. The mechanism of potassium fixation in soil$ ha$ bccn inrcslipted hy a numbcr of workers and man) thc~irlo arc postulated to explain this phenomenon. The earliest explrna- inn of thc pourriuni fixation in wil wab ofkrcd hy Volk (1933, 1934) who from mincrnlopiwl. chtmicnl and X-ray analysir of Hagerstown silt I ~ t m soik from Pcnnrylvitnin rtulion experilnental plots, sane of which hnd reccivd 5.M5 kg per ha of potassium chloride over 4 period of 50 yeilrs, concluded that a portion of the ndded potar\ic~m had reacted with colloidal iillcxtc and kcume fixed in the form of muacovitc &us cnnvcrtine sddd availsblc potassium into difficult available form. Re theory har not rwived much favour from soil scientists as the korma@n of primary l~ydr~hhermal mincralr like muscovite under field conditionsi\ not en r a q matter. But ~t is likely lhal restoration of stme K ion5 in tw cryrt:il latticc mlty he porbible in some lypeofsuperficially weathered minerab like hydruuc mic;~ whose K mily enter the l r l t ia from exchanpe whition, bus becoming niin-excbanpeable.

Pugc und Buver 11940) explained the mechnnirm of the p1a\+ium fixi- lion by colloidal clay, on the h i s of ionic s in of pot;lssi@n. They put forward !he concept that potsssium fixation was due to the entrapment of the cxchangcnblc potassium in voids in dehydraled montmorillanire minerals. Ilurinp the drying process of montmorillonite with solution of ptua,ium u l ~ r , the shectr of the lattia contract. The potassium ions (r 1.33A') lose lhcir thcll of oriented water molecules and are forced into the open hcxn~onal holcs ktwcen the l a y (r-1.4h'). These incesligatori stated thet ions smullcr than the potassium ions were not fixed because they did not lit closely enough in the surrounding oxygen ions. The ions larger th'dn thc potashiurn ions could cnkr the hexagonal holes, thus they would remain loosely bound. Standford (1948) reported that micaaous minerals could fix the potassium under moist condition which increased on drying and montmorillonile did not fir potassium exaccpt on drying. Wiklander (1941) W M ~ U ~ C ~ that in micawus minenrls fixed potassium wui bound between the basal plane\, in hexagonal oxygen cavities, normally occupied by potassium ns r lattia mnrtitucnt. By leaching and weathering a part of the lattia potassium dose to the particle surface is removed and substituted hy other ions. On addition of potassium salts, the potassium ions migrate back into thew normul positions thus rebuilding the lattice end bwming fixcd.

War and White (1951) explained the mechanism of potassium fixation in clay minerals, on thc basis of tIr s t ronp and weaker negptive charges by

JIA. 1IM Akv AMMONIUM rlltAMN IN INl)lAN FOILS !I

which potassium was hdd on the crystal latlia. They rcpclrtnl !hilt whcn the exchange complax was saturalcd with plassium ions they were htld hv :~ttractive fo rm arisin~ from both w~ahednl and tetrahnlrill churper nl random distribution in the crystal ltltice. The kidellire and the illilc rli~yv have more of the tetmhcdnl charges, which give rise to stronger wltri~c~ivc forcer at chy surfaces. For illile it wns found that a large amount of p~tu\\. tum was already fixed belween the plan* which decrcaxd the ruhrcquc~i~ potnrrium fixation. The Wyoming bcntontte. po~mring ho~h ' \lrnng' and ' weak ' charges had only a trua of pntarsium prcwt a\ a part r ~ l ~ h c original crystal structure, thus it has a high cuprcity lo lix hrgc sniolrnlr of potassium. When a clay mineral i\ dried wilh exchun~ pcfiil~on\ trce- pled by polassium ions held hy randomly distributed ' strong ' i111d ' ~ c a k '

forces, a conliguration is formd with civh potnq\ium ion\ In I'ourtecn co-cirdination. I f enough of the% $table configurations exists hctwcen any too adjacent sheets. thc bonding action of Ihc potmiurn ions will overcome the forcer tending to Yeparate the sheel$. It IS no td that fourtccn crrdi- rlalion of ptarrium arc more st:tble when the potawium ion nrutr;llircr ;I lclrahedral charge than when it neutralins an octahedral chargc a\ in ~ h c Formcr cn~. the electrostatic balance rule is snti&d over a nhor~cr dir~ancc. Barrhad (1950) however, considers that the magnitude of ~nter-leyer churper rather thon the origin or the charge determinn ation fiuclion ; NH, or K ub.iorhed hy unground minerals with a chsrpc 01 200 or morc, m. c, prr 100 g Ir nearly all fixed : whereas w~th a charge of l lOor lerh m. c. nnnc Ir limed : mlneralr with charge in rangc ktwcen IS lM) m. c. Rxcd K morc srongly than NH, hul the f iut~on o l either lr not exlencive as in mcneralr wilh 11 chargc of m) or mon m, c. A decrealc in particle r i a through grinding decrease fixation only slightly in minerals with a charge of MO or more m, e. F r 100 g but II climinntc all fiution of NH, and a large pan of Rxation of K in the mineral with a charge of 150W 160 m. e.

A consideruble cvidenct has been accumula~ lo show that there is a c r i~ la l level of basal spacing below which Ihe displacing ations arc unahle to remove ions in between the layers in thecryshl l P ~ t i m of the clay mineralx. This critical level of basal spacing had hem fixdd at abut I 2 A . I t wa8 found that potassium saturated material had a mximum basal spacing of IZA", whereas, Ca, Mg and H saturated material had a haul vpacing value above IZA" I t is obvrved that potassium fixation in clay minerals ir d m m c d i f the basal spacing in the layers is kept more than I2A' by the introdudion of organic cations ( h g t and Ravn. 1940). 11 ic alw known that montmorilloaite can only i ix potassium on drying which is required to contract the lattices and reduce the h l spacing below 12A", and thus trapping tbe K ions in the crystal latlice. This rhaMy of cwtnclion of the shea laycrs of the clay ~mls on the introdudioa of the K ions and the pnrena of a critical kvel of (he interlayer spacing below which K ions a n

prerented from exchange reanion explain the behaviour of K fixillion found 111 vermlculotn ;~nd In open illilm. I t is found through X-ray diapmms and I)'rA;~nulyris that the latticesof vermiculite, a highlypotassium fixing mineral 1, n~ntn~cled from 15.6A' to 10.9-lI.bA, i f it i s shaken and dricd *~ th n \olulinn containing polusrium. Mare1 (19540 and h) showed that in .~mmer\,wltc (opn illite) from Dutch basin strong K fixer soils. the \hcets ,.,~n~r;~c-trcl on treatment with K salt. The contracted mineral llad I!IC same X.I.,I~ ;IIIJ I)TA diapram a y Ihe common closed illite Chcltcrler (1953) rep~wtctl th;~t Iprt III montmorillonite (I0 to I S per cent) coukl be cnn~cr~ed 1ntc8 ~ l l ~ t e hj rreilting this clay mineral with KC1 or KOH 8olution undcr ;~lL;~llne rondilion\ for Iwo months. Chemical anslyr~s indicakd thilt ~rot;~s\- IUIII c.intcnt of' the montmorillonite increased from 0.6 to I45 per ccot by K('I KOll tratmcnt and X-my study indicated that illilc line ( iOA ) w3c nlucl~ more stronpcr in KCI-KOH treatedcluys than In origiml. Ch:~ttrrice i111c1 R.1) (1954) riiTcred a possible explanation ol' pota\h lixiltlon ~n \~r~l!. Vr'hci\ ~nmrntmorillomte soils ore heavily fertilized w~th potil\shm, patarklurn vnter, 1n10 the blticc makc.~~p of the day minerill and iq thus dillicul~ly ~epl:~iv.ihle i.e. it is fixed. The Knolinite soil under si+r condition\ nlnnot lix potassium. A consideration of the lattice structun ~Fthcre three cl;~y minerals reveals that under suitable conditions the conversion of nnintmor~llonitc into illite i c possible hut tr:~nrrormation o l laoliaitc into lllile %ems to be very remote. Under Aeld and lahnratory condition\ it mlly not be possible to convert montmorillonitc into illite a\ ~tated by these \\orken hut potnssium fixation an reduce the haul spacing hetween the Iitttices ~tnd can convert the expanding minerals to nonsxp~nding fiirmc. (ircwnl (1964) reported that potnssium adsorption is the first step towilrds ~)(~n~\siun~ lirution. He found a highly significant pojitive correlation (r -0.914) helween the potnssium adsorhed and fixed in the Punjab toils (Fig. 5) . Nearly one-third of the potassium adsorbed was fixed by thew \oils. Raman and Jnckson (1965) studied that the mica cleavage morpholopy chnnpd during potassium release and fixation. The electronic microscopic b~udics ofthe surface of biotite micas beforc and after the weathcrlng treatment have provided a clue to the potassium releax and fixation properties of micacious minerals. On treatment with sodium tetraphenyl boron to rtmove interlayer potassium, the boundaries develop into frayed scrratcd edges and under the livering action of the hydrated cations. the layen roll hsck reslllting ultimately in the formation of a number of tubular rolls on thc surlhcc. On tmtment with the potassium salt these layers unscroll Glirly smiwth back owr the surface. The resulting surfaas have a smooth c ~ v y appearma which could be the mult of either breaking and loss of u l r of the layers or the pnsenoc of some trapped material in the inter- layers or both. The conapt of the flexibility of the individual layers, their rolling a t the e d p on potassium relcasc'and thc unrolling on potasium

R)TASSlUM AND AMMONIUM RXATlON IN INDIAN X1lI.S 25

fivalion explainc thc adverse efcctr o f surfaa tension on pcrtwnle rclcare on drying and providec a dirccl oburvali~in o f nn alignment of cr)rl:lllo- gr:~phlc ritc.; for K prcfcnna noled in m i a derived expanrihlc ni~stra~lr

Thcrc tire Icw rcfcrcnm to indicate Ihnt some of thc rmounl of ~II:I\~.

lilni Iix;htioci biles place through microhinl ;~gencin. Hum117 and Ratchclt~r i 104~1 found micrcibiolopial fixation o f potnrsium in u111e;lch:ihlc fc~rm up to 224 ?IX) kg per ha cln addin$ plant nlaterial to neutral \!It In;lm, Th~s t!pc of l ixi~tinn nlipbt he mcurring during moist cnnd~tion n l n1;111y roll\ 111:inurcd H I I ~ organic matter. Alcksandrc~v (10!0) :idduced c ~ ~ t l c ~ i c e 10

\II~IH th:~l m0hili7:1tion and fixntion o f potatrium in wrorrm ilnd chcrno7cn1 *n~ l t wcre due to hiolopiwl ngencies. Prcxniv or nldltlon or' org:rnlc m:ittcr greatly intcnrificd potn<cium fixation. Hc \liowcd thut k i t h fix:~tlon l ~ ~ ~ ~ i rnoh~Ii~:~tion were fundurncntallp hiologial in nature, k i n g elli.c~crl hy Ihr prcrcnce or organic matter, paniul cterilir:~tion and hci~ti l~p Ihe $011

. \ccnrdln~ 10 him Ihc mincrali~alion of orpanicr~~brt:~~icc$crin!;tlnlnp pclt;i+r ltlm W;I* hroughl i~houl hy thc ;iction of rillcute h:iclcri:~ which :~tt:~ckcd >rill nilncr;~h. c:nl\inp lirrlly lin:ltion i ~ n d \uhrcqucnfly n ~ i n c r a l ~ / i ~ l i ~ ~ ~ i o l ppt:crr.

gum. The abuve view i b however, not acapted by number of worken who constdcred fixation of potasdurn in .+u%mt quantities in the bodin of soil n i i c r w r ~ n i r m s a ~ dillcult lo accomplish. I n he acid soils when bacterial p)pulution do not h i v e well, the Axition of plassium is due mostly to inclrgmic rturtion. The organic matter was on the other hand reported to wllucc the inorganic potassium finktion. The simple explanation for this i\ thut he K salta of organic acids a n weak and ionise less, thereby reduc~ng the clTcctivc concentration of the potassium ions in solution which can be cnnvcrtcd inlo the excbnnpeablc form and from that into the Bxed cond~tion. I t I,I:I~ aI\o be p$Sihle thut the organic maltrr blocks the at t~ct ion spts in tllc ttiincr~l lilttias responsible for the potassium fixation a$ even prevent thc ihrinkage of the crystal laltia! which is found nmssarydbr some type of thr Inorganic potassium fixation.

Porus.~rrrrn firation ~pariry of In& mils. The potasriud fixation cnpa- ctty of mils varier greatly depending on the methods used f i j study. The nicthcds uxd for the dctcrminution of potassium fixing cadcity of a soil arc ormmonly h a d on the following procedure. A known amount of ncutrttl pol;~ssium salt is added to a certain amount of soil. F f t r r trmtinp Ihc aclil and aolution for the desired time (wet fixation). the sol@ion i s filtered OK The soil i s washed with the salt solution, which leaches &t soluble and e~chanpahle potassium. In the filtrate thc potassium is determined. In an untreated umple of the soil, the soluble and exchangeable potassium is determined by leaching with the same salt solution. From the amount of pe~aaium added and the potassium conantmtion of both the Icachates. the amoust of fixed ptarsium is calculakd. In care or dry fixation the roil and solution containing the potassium salt are quilibrated and dried atn predetcrnli~icd lempcrnture md then treated the same way as in the wet lixr~tion. This proccdurc is purely conventional, as (he amount of the added y~)tns\ium solution, the amount of soil taken. the reaction time, the drying prondurc and the silt solution used 10 remove the water soluble and the c\rhangcable potassium are chosen arbitrarily and their variation can effect ~ h r pc~ta\sium Rxation capacity of the soils.

Although it i b very difficult to mnke e comparison of the values of the potrfiium fixilkion capacities given by various workers for the different t y p n ill soils. as their values can differ with the technique used for this study, but the results obtained by different workers a n discussed below.

Chatter* and Ray (1944) repond that under alternative dry and wet ci~ndi~ions mon~morillonite can fix a wnsidcrable amount of potassium when the clay is tmaled with large amounts of p d u m salts in a filightly alkaline conditions. The potassium mateat of montmorillonite inncDxd f m n ~ 0.60 to 1.45 per ant. I n their later Mi Chttcr ja and b y (1958) reported that H-montmorilhite on Rplrtat treallnent with pntadum chloride and dsnmratioa Bxal nearly 55.0 me. of potwiurn per 1008 of

PuIA. UM ANU AMMONIUM HIATION IN lNDIAN W U 15

clay mineral which i n m a d the potassium wntsnt o f montmonllu~ti~c from 0.5 t o 3.01 per an t .

M i t n el a/. (1958) n p r l e d he po(ansium fixution eupcilin o l I a J ~ r s soils and clay minerals under wet conditions when potrssium wiis appl id u~ one aymmelrical value. The nsults o n given i n Tablc 19.

TABU 19. POTASSIUM UXATlUN CAPACITY Of CLAY MINLRALS ANI) WML INDIAN SMLS

-- . - -- --- . - . - . -- . .- - - -. h l i l y So11 group K. Pucd K , liard

(m.e./IOU 8 ) (p~cntup) .

Uclgnum Ssmi.uid red 0.2 0.W Co~mhtorc 4 5 25.54 hfdruloru I ium~d red 7.97 12.N Ralpr 0.00 0.W I)umlw 2.53 15.02 Padcgaon Scmi-nrid black 7.06 12.31 Sdurashtra 1.20 11.1 Iiy&ratud 3.67 9.1: Naypur Humid black 7.67 18.75 Knijrt 9.76 21.31 Alwaye Lntcnlc 8.79 11.62 K i l rn~ l A r~d B K~I-arid 1.93 21.1

alluvial Sunlmcrpur 0.95 11.9 Oclhr 4 , IW.7 Nabhn 0.34 3.47 Puu Humd alluvlnl 1.02 2o.M Or~rsa 1.75 24.3 Aduthwai 2.W 12.64 Burdwnn 8.45 18.35 Tnpura Prchum~d alluv~al ).a 1.29 Aunm 0.45 9.00 Manmn~ Forat roll 1.01 13.26 Rcntonifc Chy minerals k98 12.73 lllife 10.93 52.54 Kaolin~te 0.33 7.59

- . - - - - -- .- - - .

Thc potassium fixation capacity o f the t h m clay mincnlr diKcrcd greatly. being 52.5 per ant for illite. 12.7 per a n t for bentonite and 7.6 pr a n t for Iraolinite, The potassium f h t i u n capacity o f Indian wils n p r m t i n g the di6ercnt coil g o u p ranged from 0.94 to 26.84 pn m t with a mcaa value o f 12.87 per m L Thc arid r o d semi-arid coil$ o f KamaI, Summnpur, Whi. Saurashtra, Belgwm had on wet'a~ po tw ium fixation

capacity o f 12.97 per mt, the humid soils o f Malutcru, Raipur, Dumkn, BII~W Ns NU, Y-piat, M u l h u r a i , ~ pad Puso hadm averagepoW

ium 1iaa1ic)n capacity of 16.7 pcr cent whilc the prc-hum~d roilsol Alt+a!r. I rtpura aad A\\:rm hid an average potasslum fixatiim capcity or 7.3 Ixr ccnl. Tllc iltcnge potassiiiia fixation for red. blwk and alluvial boils was 10.0 pcr cent, 14.55 per ccnt and 14.9 per cent resplively. 'They ind~catcd Iha~ nalure ol' c l ~ y minerals and climutc determines Ihe pot~arium Iiaaliur~ apaci~~cr, of rolls.

1';itliab cr ul. (IYN) and I'athak (1954) studled the potash lixing r;rp,~. city 01 ~I,IIIII~C~ and unmunured soil, of Kanpur (Utlar Pradc\h) ;is aliened b) continuau\ cropptnp. They repurted that deatruction of (he org:inti irlatlcr isuret~rctl 11ic poli~stium fixallon In both the aoils. The rill and clu) Ihiuln)~~ ol'lllc soilr were lrrgely responriblc for potash fixstion and (111.

pola\riun~ lixi l~~on capacity of soilr increased in the lower Lycn 1.e.. 15.25 cm to 30.50 cnf and 30.54 cm to b l om. The silt frnctiun on ;in averape lined 6.H') ~ n g lwtaraium per I00g for the nanureditnd 6% mg per I(X)g l i ~ r thc unnlanurcd so~lr. The clay on an average had potash fixing capaclly ul'6.'W nfg Ixr ccnt Cor mi~nurcd and 7.10g per n n t for the llmanurcd rolls. Thc rn,lllurcd roil, on ;in Average 6xd 2.12 mg potassium pb 100 g and thC unmslfured \oII\ fixed 1.27 nig putiwsium per I00 g soil. ;The bdrugen perobtdc licatcd inunured soils hod 3.05 mp per cent and pmanured rolls h:ld 2.70 my per ccnt po(ilrsium Ixalion capacity. The 6ela1lcd rcsul~r arc glwn 111 Table 20.

TARLI. 20. RIIASSIIIM HXAIION OPACITY (MG 7;) OF ALLWlh: SOILS ,\\I) IllLlR MtCtUNICAL FRACllONS

Manured Unmarmred

Pelhali und Sharma (1903) rep~& that normal cultivated soils of Ksnpur (liltar Pr;fdesh\ fixed 40.0 to 73.4 per cent of the applied poras\iun~ (1.5 r)mmctr! tulue) with a man value of 57 per ant. It wus 42.82, 56.65, 73.42, 71.55 and 40.83 per cent, by ~ h c application of KCI, KSO,, KIN, . K,HP@ and KH*PO,, respectively.

Misra (1958) studied ac potassium finalion from potassium phosphate in thee soils of Allnhabod (UtW Radsb) a d h h m i r bentonite unhr

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28 I. S. GRWAL AND I. S. KA~. IAR

Mchta end Shah (1956n, band c) studied the polassium~fixation cap- cllles o f t h m wils of watern India, namely gorodu, kiuri and black cotton wils which are given in Table 22.

TAHLI 22. FIXATION OF WTMSIUM IN W ~ R N INDIAN SIIIIS . , . . . -.---.--------

Amttunl or K added Soil 11. E. C. Fixation 0lm.e. 1100 g Soil (prriod in b s )

m.c 11008 S l r~ l n1.s.1100 p

The rquil~br~um was ntrrblished in 210 days. ~ c a r t 20.2, 38.3 and 52.7 p r ccnt of the applied polaasium was fixed in goruI@ kiari and blilck cutton soils rc\pxtively. Chauhan and Singh (1967) stud the potarwm lixutiun ci~picity ul'bl~~ck. soil (Indore) and alluvial soil (Gw !r ior) of Madhya I'rudah. The hlack hail tixed nearly 59.3 per cent and qfluvial roil fixed 42.0 per ~ m t of the polavslum applied at the rate of 2.0 m, e. per 100 g roil as murlalc of potash. The detailcd results are given inTable3.3. Had~gcr and Vtntuta Rao (1969) rc?urtrd that black soils of Myson wrth 2 : I t ) p of clay mincrals fixed comprativcly more potassium than the red roilr uith I : I ~ y p of clay niincralr.

Prurad 1.1 nl. (1967a. b) rcportcd the potassium fixation capacity of repremtulcbc sedenlury and alluvial soils of Bihar unda wet condition. 'The result, ore pircn in Tuhlc 23.

The sedentary soil fixed 0 to 39.75 pr a n t of the applied potassium (1,WO ppm K) with an average value of 22.72. The alluvial soils fixcd 18.66 to 47.78 per ccnt of the applied potassium with an average value of 32.73 p r cent (1,000 ppm K). Tbc potsssium hation was high in Raxaul, S a h m , Patna, Newadah, Biluamganj,SPbour and KatiharJoiir and low in ChPibass,

FOIA UM AND AMMONIUM FIXATION IN IYDIAN WHIJ 20

Hamribagh and Arnria aoilr. Undcr allcrnarc weitin8 ilnd drying rond~. tion%, the potassium Axallon capacity of thc wil* v;lricd from !?.(I I~I XI 5 pcr crnt with a mew valuc of 56.41 pcr cent.

G m l and Kanwar (196711, b and c) reporrcd the potli\\lutn I I \J~I~>~ w p c ~ t y of23!,oils of I2 districts of Punlab, Hsryarul and ti~ni:~chz~l I1r;lde<ll undcr WCI and dry condition\ when pola$siumwar appl~c~l rl tbr rxlc 01' IJXMI ppni K,O. Thc pcrccnlagc poluraium fixnl~.)n I\ pivcn tl~\lricl-NIW III Tahlc 24. The polassium lixalion on ~ndividual \oil haw barled fmni .I.$( to 26.85 pcr cent, under wet uondirion\ wilh i t Incan value of I (L)5 pcr cctit. On dry~ng the soil UI 100 C, after addinp thc pola\$iunl *all% ;I( tlic rrlc o l IOOO ppln K,O, the vnlucs ranged fru~il 8 .00 to 33.98 per ccrt. nilh ;I maill valuc of ?0.0$ pcr cent.

~nlblld' Jullundur P~,llala

Grcwal nand Kanwar (1966) reported that Ihex boils i l l u ~ conlnlncd apprcciablc amounts o f native fixed potasium wbich vuricd from 7 0 5 ro 162 mg per I00 g sail with a mean value of 117.6 mg p r 100 1. Thee xr~l r contained mainly illite types of clay minerals which are ma~nly rcy)on$lble for the fixation of applied polasium. Hasan and Vebyutham (1971) reported that thc alluvial soils of Dclhi and thc black mil* of Coimhalorc treated wilh direrent concentralions of ptassium on an avcruge fixed IS ? and 11.6 per cent of the applied polab5iurn mpativcly undcr wcl conditions and 23.9 anit 16.4 per ant respectively under alternate welling and drying conditions.

4. FACTORS AFFECTING POTASSIUM FIXATION IN SOILS

Tnw.1 are a numkr of factors which affect potassium fixation in soils. The ~nl'orlna~ron ava~lrble OII ulmc of the impomnt faclor\ which ~nflucnw the potarrium lixut~on in \oil% 15 dtxus\cd below:

('11~ s~mrruls. It lr well known that the povdssiurn fixat~on capicily of KIII\ s~uch depend\ on the type of clay minerals pnscnt. The soils mtlpr~nlny ! : I type of clay mlncrals like illitc, vermiculite m d montmorillonitc can fix a~n\~deriiblc amountr of polussium. A btcrifc soil containing kaolinite type or cley mineral fixer very little amount of potassium. Stan- h1.d (1'14X) lbund thi~t mici~cctrus clayr like illitc can lix cor$idcri~blc amount of poras\ium under n161i\t conci~tlon whlch increa#e\ wh? drying cxcurr, wt~~lc tlie n1111erals ol'thccxpandinglultice~ l~ke benlontle ddnot l i ~ poraulum crcrpl H her1 drying occur.\.

Chanerjcc md Ray (1954) reported that under the akalinc cond~tlons mon~morillon~tc can lix a cotisidcrable amount of potasrim when the clay is trcatcd with large amount of potassium in sl~ghtly rllgline conditions. Tl~c K,O content uf Kashmir bcnlonitc (montmonllop~te) was r a i d from 0.W to 1.45 per ccnl by the pohssium trcitment.. But under the s~miler cond~t~oss Loolinitc could not fix i~ny appreciable afnount 01 polass- iuni. Chutlerjec .end Ray (1958) r e p r t d that H-montmoriionite on repeal- ed treiitmtnt wllh p~tissiltm chloride fixed nearly 54 m e. K p r lOOg of cluy mi~lcral which i~vre;t,cd the potassium content of montmorillonite from 0.5 to 2.01 per cent. Thus the problem of potassium fixation in-soils mainly ;Irtrc when they contuln illite, montmorillonite and vermiculite types ot clay minerulr.

/ ~ o t o , ~ . ~ i u ~ n c~acc~ntruricnt. The potassium conwntration in ,011 is an important hctor to influence the fixation and relcav of potassium. An inrrear in po~sssium co~~antrntiot~ is likely to increase the potassium firation b u s e more pra,sium goes into the exchange complex by mass action which is considered the first step ror fixation. Wiklander (1954) shred that in acsordana with the equilibrium formula, both the capacity and rate of potasium fixation should increase with the conantration of added potarb ium. A boil not 6x1n0 potassium at a certain concentration might fix it at a higher conanlrntion.

Mehta and Shah (IVSba, b and c) studied the potassium fixation in loradu roll of western India at various colloentrationr of applied potassium. The rrjulls a n prevnted in Table 25.

The pobssium fixation increased from 0.009 to 3.08 m.c. per 1008 mil ns thc applied pomsiurn increased from 0 to 15.0 m.e.1100 g. Thew was no further increase in the potassium fixation at higher d w of tk p o k u m applicution i.c. 20 and 25 rn. e. p r lOOp .&I. brim and Mlkk (1957)

rcporttd rncrcased total and prrccn!dpr ol' the pola+sium tlxalro~i In I .~\t krigal (now Bangli~dc$h) rorh ;I\ thc c o ~ i ~ . c n ~ r a ~ ~ o n of i~ppllctl potarrlual incrcad frum 135 11) 673 Lp per lid. I hc rerults arc rulxrricd III l'uhlc 20

Chauhan and Bngh, 1967, rcponed that pitrblum li \af~un In the bluck wi l (Indore) and the alluvral soil (Gwallor) cncrtawd with tllc incrcilr In potassium conccstrati~ln. The dEtrlllhl rc~uIt\ arc il\ under :

32 I. 6. GRLWAL AND I. S. KANWAR

Yrnud rf at. (1967a and b) reported that in the dcntary and alluvinl milr of I ltLr, the incrcasc in the ctlncentration or :~pplicd plassium from IW to W n l g K,O per IN)p ofsc,il incwxd the amount of polas\ium Aaa-

hut the pcrccntilgc of pta\sium fixallon was maximum at 250 mp K O applicution. Grcw;tl (1964) and Grewul and Kanuar ({%la, b and c! studled the potarrlum liaalroa capacity of the PIInjuh. Horyam and Himachvl Pradnh hoilr at 100, 500, I,O(X) 11nd 2,000 ppm K,O appllwtion. The rcrult, arc given in Tahlc 28.

There W:I\ increase in 1t3.c total 3nlOUnl o f pot;l\sium li.teJ wtth the incwascin the plussruni applicd hut thc perlrntagc putusrlum lixed dccrcil\- ed with the incrcue 111 the conmnlration of app l i~ i pta$sium. They indl. w t d that pot;~ssium Rvalion could be 6ttcd lincurly into langrnuirr adrorption isotherm. Where C is the equilibrium concestratlon,of appltrd polassium in ppm, 41nd X m i a the potassium fixation in ppni. All theit n$ults indicate th:~t the increase in potassium conoentrale in soils leada to higher potassium lixolicln.

H'rrlin~ and rlryir~g. The hndion of ~olas~iurn in the soils is strongly i~lf lt~ennd hy wctting and drying of the soils. There may he either fixation or relcau of the potab~ium in Ihc soils when they are dried. Cienernlly fixatic~~ occur; ~ l ~ e n the initial lcvel of exchangcahle and soluble potassium is high and releusc murs when the lwcl of such potassium is low. Appa- nntly the cfTectr of drying are associated with the attainment of an equilibrium in dirtrihulion of potassium among h e various forms in the soil. An increase in the pntassium fixation on drying at higher temperiture can he expected, >inn higher tempentun favours dehydration and contraction of the crystill lattice with ptassium ions in the voids. The drying of the soil also incmaw Ihc mnnntntion ofpotsssium ions in soil solution which lads to more potassium fixation. I t has been otaand by a number of workers that anain clay minemls likc moatmorillonite can fix the m i u m only on drying a b r the addition of potPrsium solution but some drys likc illilr 1 fi., some. of the potassic 11 dw moist co dilio .

POTISIUM AXIJ AMMOYIIIhI f lXAT l l Jh 14 INI)I4L; S ( I 1 \ 33

Grewal and Kanwar (19670, h and cl rep~rtcd t h l ~ the potneiun~ fixation in wils in Punjab. Hiiryunil and Himchitl I'rulmh i n c m d by drying the roils at dtkrent temptaturn after the add~tlon of polusdurn salts. Thc dctailed rc\ults ore given in Tithlc 29.

So11 <,mdll~un K . 0 liulllm Pc~~wlryc h ppm Iir.~l~cn

Mol<l I ? ~ c r r c Dr)~ng nl MY' 182 18.25 I l n ~ n y 111 100.C' . . W.4 ?c).nc ~llerndlr wzlllnll and drying r l IMo(. 226.3 22 - .. --

Prarad 01 a/. (1967a) reported that sedentary and olluv~ul \oil\ of Hihrrr on nn avenge R x c d 27.75 per cent of the applltd pol.t\\iutn ll.O(Y) ppm K ) under wet cundlt~ons and 5041 per ccnt under alW~~ate wcttinp i~nd dry~ng condition$.

Huun and Velnyutham 11971) reported lhat the alluv~ul soil\ of Lklhi f i~ed on an svcriige IS.? per cent of the applied pta\sluln undcr wcl cnnlli- tion\ and 23.9 per ccnt on allernale wcttinp and drylnp. The black roll, of Colmhatorc fixed 11.6 per ccnt ofthe applied ptasdum undcr wet conditiuns and 16.4 per cmt undcr alternate wetting itnd drying cond~tion\. Knrim and Malck (1957) slur reported that incrcdrc in the dry~ng lempcrilture of thc wils ~ n c r t a d pota(ilium l i ~ t i l i n .

PN. The c k l oIptf on the fixutiun of War\ium ie \nil\ ha, heen a con~ro\crsial cabject lor maey ycan. Thc re\uII\ or:^ I;trpc number 11f c\perlment\ to dctcrminc the nnlurc of rclat~on\hip bctwecn ui111 itnd pH a3.l potn\\ium firation kt\ heen contradictory in many case\. NanJy (1946) reported that it war only at pH 6.0 lo 7.0 thac Ihc potaolum fixation or the po~arsium rcleaa occurred wh~le l~ming rbe acid~c +ails of &npl. Thc liming libcrated the potacsium bctwccn pH 6 to 7 which recntrrccl the toils complex and was again fixed, if not removed.

Karim and Malck 11957) reported that In Eact &n@l (now Bunyl;~. desb) roils liming increaxd the potassium fixalion and the p h i u m lixn- tion decreavd significantly with lowering of soil pH. Thc application or 2.5, 4.5 and 9.0 tons of lime per acre to four soils on an avcrag increased the potassium fixation capacity of thew soil5 from 31.5 per cent to 40.0. 48.5 and 71.9 p r ccnt of applied potassium (269 kg'ha) rnpativcly. The d e w of pH of thee roils from 5.3 to 4.9 and 3.3 dccrcaxr the potastiurn fixation from 32.2 to 30.7 and 15 4 perm1 of applisd plarrium (269kglha) fcspeecivcly.

Omal and Kanwar (l%7a, h and c) found that pohcdum fixation i a c m d from X0.Z lo ?bh..l pfim with sn Incrcic%c In pH from 4.0 In 10.0 when I,O(Xl ppm K,O wr\ nppllcd. The dclailed rc\ult$ arc givcn in Tahle 30 and F I ~ 6.

TA~I.E 30. E l lcCl 01. p l l < lV PtnASSlllM TlXAllo\ I V P~INJAU AND I ~ A K Y ~ ~ A SOILS

In gcncr;~l i! 1s con5idcrcd that ;in incrcae In pH o l a >dl lei~ds to higher pitarrlum likati~in clnd ;I dccre;~r In pH decrease$ the petasslum fixation which in hydrogen-satuntet \oil\ may bccomc neglig~hle. Rut all the soils may not cxh~hit Incrcarr in the pt ;~s\ ium lixution. II' their pH ir incrcascd.

Lurhoi,ct~crhb' r urinrrr. Thc nature or the cation5 present on the soil ctchnnpe oimplcl plays II dominant rolr in dctermining their potassium lixulion ~ i l ~ i t ~ l l i ~ . Mchtn and Shah (19561. h and rl r ~ p r t c d ~ t h a t goradu soils or weslcrn Indian a;ttur.;lcd w ~ l h dilferent ions, had the potassium

I' 9 . . fixation r:lpc;l) in Ihe order N;I> Mgz C a r N H , r H. The delnils are eivcn in Tohle 31.

TABLE 31. Fl~brlON OF POTA%UUM IN $orah .FOIL SATURATED WITH INWbRKNT CATIONS

Poluaium uddcd rn.f./100y htasium fixation m.c. /lDO 8

Parhnk and Sharmn (1963) reported [hat the calcium saturated Kanpur roil? showed greater paastiurn fixation than hydrogen saturated or n o m d wik. Pnsad rt a/. (1%7a, b) nported that in the sedentary and PI1uYi.I

wilr of Bihar, application of mlcium (203 mg pcr I0 g \oil) tncrcn\nl the potassium fixation Rom 27.15 to 40.35 pcr ant. (irewnl ac~d Knnuur (1%7a, b and C) reported that 23 Punji~b. Haryuni~ ilnd H~mach:ll rullr with different muons on the exchunpc c o ~ t ~ p l e ~ liked the polaruunl in tile follow~np order N. t -C~>Mgr t ipNH, soil\. The diteritpc polu\rnlm fixation of lhc s.~lc s:tturntcd with difercnt n ~ t ~ o ~ r \ war nr under ~IICII K,O am applied ill the rrtc o i I.MN ppm.

N . I 194.5 plim K , O t t

Ca \oil\ 176.9 ppm K,O 4 t

MI uril\ 161.2 ppm K.0

Ht \oil\ 47.4 ppm K,O t

NH, \oils 14.5 ppm K,O

The Icrs potas\ium fixati~rn in prercna of NH, and H Ion\ ir

attributed to the fact that N(H, and H,O 140 ' HI ion, compete fi,r the same position in the lattice where polasvum ion\ arc to be lixed.

The nature or the cations in the extracting rcllul~on spin\! whlch the p~la#sium i s fixed in the roils alto has preill kdrinp on Ihc potilrrium h a - tian. Mehla and Shah (1956a. b nnd c) rcportnl that rn forudu roil of W ~ t c r n India, the prercnce of ammonlum iom In rolutlon reduced the fixation of ~ u s ~ i u m . The order of cornpcl~tive abil it~n II~ ionr In reducing

1 i t i i t potar\ium fixation war in the.L~llnwinp ordcr : NII,7Ca:+Ml(rNa Grcwal and Kanwar (1%7a, h and c) alw reported that ~ h c p)tarrtum finit-

lion In Punjab soil, vaned with the nature of the rcplrclng cation$ and 11 . + r . . 4 ,

dccrcoscd in the following ordcr NH12 H r Caz N a z Mg. The a - tent o i K,O fiwtion on an averapc war a\ under :

Ammonium ion$ - 159.5 ppm K& Sodium ionr . 131.1 ppm K,O Magn~ium ion% :,! 126.8 ppm K,O Calcium ions : 136.6 ppm K,O Hydrogen ionr -: 1N.5 ppm K,O

The diferena was sipnifimt except between \odium and magnnium ions. The high potasslum fixation in ~ o ~ l r against xmmunium and hydrogen ions probably is duc to contraction of the clay latl ia by there iont. The magnesium and sodium ions expand the lattices of the clay minerals and thus k l p in replacing some of tbe fined pdauium. As thc sire of the polassium ion is aa important factor in its fixation, similarly b impwtnnl

36 I . S. GRCWAL AND I. S. KINWAR

the rirr of thc c;ltion\ for rcplaclnp the fixed plaa\ium from tlrc u)il ex- chol~ge ntmplex. I h e wtront of \miillcr size or the hydrated ion5 c;ln easily cntcr inlo the clity let l im and rcplsct some of the fixed potasrium.

Tlmr. It is prcvumcd that potasalum fixation procmls from thc sur- fna\ nl~d migcs to the inurior of the soil particles and thc raw of lixation dcyntl\ on ion\ dlflurion. Potiltrium fixation 15 likely to he rapld in the kcpinning and continue lo slow down as the naction pravcdr toutlrdr thc cqsil~hrtum point. Mchra and Shah (195(,i1, b md 0 found tb;~i 111 rhc ,yorod~r. 1111r1 and black cotton soil\ of wcrrcrn Indra. ~ h c lwrasc ium liration incrcad with incrcahr in time contact up to 210 du)\ whcn thc potswum wa\ npplred at the rille oi 15 m.c. per I0 p o l r o ~ l (T;\hlc 2:). A h ~ ~ u l 94 pcr cent c~f Ihc pota\$ium was lixcd in 30 duy whiclr %a\ the ah<rrtc\t priod rtudrcd. The! li)und that Ihc cquilihrium War c\I:~hl~\hcd earl) i f thc nmount of poti~*\ium ;~pplied war less or the cstlon elchange c;~p;lc~ly of the 5011 W;I\ htgh. Kitrtm and Malclt (1957) worhlnp on thc cl:~y loam, rllt I ~ u m and unt i l loam soils of the Earr Hengal found that the potu*\rarn Cxution ~ncmirud h) increau in time up to 60 day\. Thc Intcn. rlty of the litiltion wn\ grc;ltc\t In the ltlsl day\. Thc p~~t:rwium litation on ;In ;tver;rpr !\:I\ l~l'tltc ordcr rd?J.V. !!.R, !Y.?. 49.2 :rnd M1.6per ccnt rrrthc f i~pl ln l puI;~\\ian~ (269 k; h ~ ) :~frcr 7, 15. 30.45 ;lnd M) d;ly\ rc\pxtivcly.

f " PI#, 6. llslrtiondrip tam pH and pamiurn BUliO. aplcily d will.

Chnuhan and SI I I~~ (19671 fouml lli;~t muxinlum fix:~l~t~n 01' 111c ;~ppl~cd potacsium that ttwk plilm In onc month in the hlach #oil oS Illdorr :III~

alluvial wl l of Gwalior *a$ nearl! 92 p r cent. The Jtl:~~lwl rc\clllr ,lrc glven in Tuhlc 32.

Grcwnl illid Kilnwar (1967) rcportnl tllat in the entwh~le Pun1.1h roll\, 90 pcr ccnl ol'thc pc~ta\bium lixal~on ttlnl plna in one d;ty i ln~l the cqoll~. hrium war c\t;thli~hcd in scvcn day\ Thcdiffcrcnce In the rate oflhe polo\\- ium Bxalion In different soil\ cttn he due to the nature of the clay mlncr:~lr present in the roll\ ;lnd the method ofdctermimng the prts.islum lixallon capacity. It means that ~herc ir l~tl lc danpcr of lor$ of yrlssh from Iwrlilr\- ium fixat~on on appllcatlon lo \nil\ as I! gets quickly rr:~nskrred 10 n#ln- soluhlc or fixed li)rnls.

Tcrrrrrt*. It ir well recognisecl that liner fraction5 of thr wil arc nl;un- ly rcrpon\iblc for the pol;i\\iurn.lixation in soils. Pathilk cr 01. (19%) reported (hat rill and clay Srac~inn+ of lhe KilnpUr (U.P.) roil* wcrc lar$cly retponrlhlc for the pou,slum lixi~ttoa. On an aver;lgc. sand, rill and clay fmclion5 fixed 0.33, 6.53 and 7.16 mp polarrium per I(X) g retpeclivcly. Mehra and Shah (19Ma. b and c) reported that in porrnlu snrl scpnnleo, the wtas\ium fixation decreavd with the increar in particle cvc hut the cosne fmctlons of soils alw cnntrihutcd la the total fixation of prtarrium. The details are given in Table 33.

- - -. . . -- . . . . - - . -. .. .,

So11 rparatn Per ant of roil Potauiwn fixation wprratn a.r.ilW g

Kitrlni and Maleb (1957) alm firund that in the Eart k n p r l soil%. the all1 ir,~ct~cr~i In addltlon to the clay Sractlrln a<<umcd a role in potasrium lixa- [Ion. Cinwsl itnd K~tnwur (1%7a, h and cl reported (hat in the cntwhile Punjah collx. XS.0 to 97.H per cmt ofthe ptaorium fixation war due lo the clily Sradi(ln only. T h w soil\ contained ill~te type\ of clay minerals which wcre rctponuihlc Sor potassium fixation. It iq not only the amount or clay hut ill\o the nillure ofthe clay which I\ impor~nnl In determining tlic pol;lr\- ;em li!iltion copncitier of the toils.

Anbnr. I t was generally conridered that anion\ had lillle clfcct on the p~t;~\riurn lirnl~on apacitin or ,011s hut thc studlc\ arried out h! Mehla and Shall 119563, h ilnd c) rcprtcd that In thc pnrudlr ~ i l r of Wc\lcrn Indi:i. thr potanbum lixotion rrom KHJ'O, was pru;iter ;ha$ from K('I i~nd K.$O, whcrca\ there was nodilTercncc in the potr\rium lixahn from K,SO, and KC'I. Karim and Malek (1957) reported that plas\ium lix~rli~vi In the I3rt 1lcnp;ll (now Uanghdcshl soil\ war highest from K,CQ:l ;I\ con~p;~red to K14;0,. KC1 and KNO,. Tlicrc was 11 strong rclationqkip kcween the c~chi~~l~cahlc ci~lcium in the soil ilnd the Ix,tsstluni lixatidn lrom K,SO, nntl K,('O, It was Sound that greater the amount of e*~npeahle calcium, more would bc tlie pras\ium lixac~on from K,SQ, itnd K,CO,. A similarity was round hetween the amount of the poussjum fixed from KC1 ilnil from K,SO+ Pathali and Sharma (1963) studbnl thc elTect of tl~lTcrcnl unions on potash fixing power of the normal cultivated sod\ of Kanpur (Uttar Pradcsh). They ohrerved that the potash as phorpha~e showcd greater fixation than the sulphatc or chloride. Among the diffcrcnt pko\pluter. K,I'O, showed thc highest fixation. The soil fincd 42.82, 56.65. 73.42. 71.55 and 40.83 per ccnt ofthe applied potas*ium (1.5 rynirnc Irk valucl fr~im KCI. K:SO,, K, W,. K,HPO. and KH: PO, resptivclj. Sonic !r.orkcrs have also reported that silicate Ions influcnccd the p~tatzium liruttnn in soils. I1 i s found that the clays treated with KISIOa liked niore p>t;wium than thc clags t m t d w~th othn potassium ralt'i.

Orytif~ic n~uffrr. Thc role of orpanic matter in the phenomenon of pola\\ium fini~tion i\ controvers~al. Previously it was wnsided that the organic nl:ttter helps the fixation of potassium in the bodies of m i c r ~ r g a - nlrm. hut now it is viewed that (he organic matter decreased the potar\ium fi\ i~t~on h! the inor?an~ccolloids. Pathak rr a/. (1950) reported that remottll ol' the orpanic mattcr from the manured and unmanured alluvial soils of Kanpur (U.P.l increased the pobssium fixation from 2.12 to 3.05 mg per 100 g in the nunured soils and 2.27 to 2.70 mg per 100 g in the unmanured soils. Karim and Mulek (19571 also reprtnl that removal of the organic mutter from b i t &ngal soils increased the potassium fixation capcity or the soils. The detaikd mults a n that on an avenge of four soik the removal of organic matter with hydmgm peroxide innwsed the potassium fixntian cnpcity from 32.0 to 47.0 pcr ant of the applied potassium

(26Y kfi>'ha). Pnud t? ul. (19678, h rind c) repc~rtnl l l ip l In \nientitr) and alluvial soils n f Bihar. Ihe removal of orpnic maller w ~ l h H,O, darcarcd the potassium fixation capacit) of w ~ l from 27.75 10 8.2 p r ccnt. Nciirly lhcrc was 21 to 96 per cent darcii\e in the potassium i ix i l r~ t~n o ~ p c ~ l y of soils with Ihc removal o f o r p l i c matter.

&~.rc r~rt.hun,ev taputiry. I t hat hccn rcporlcd h) a numkr or ~ o r k c r t ~ h a l when potiis\iun~ ion\ ;ire l ~ t e d on ntm-crchu~~prhlc form 111 thc lutllcrr o i IIIC c l q rn~neral\. thc ciilion cxch;lnpe r;~pitr~t! of IIIC cl:~) mlncr~lI\ I\ reduccd a~rreqx~sdlnpl!.. Mchva and Shuh l lY56;1, h :isd c) rcp~r~.Inl t l~n l thc potarrium tiration dccrc;ld IIIC base c\chanpc capacil) ol' tl\c ~ l w ~ ~ t k r . A~arr and black coltim s(i~I\ of Wc\tcrn Indlil but thc tlccrca\c III llic h:l% exch:inp capacll! Ha\ noi q u i l l to the pt~t:~\\~uni lixnllon c;lp;lc~t\ rrl'Il~c\e \oil\ (Ftg. 7). The! crh\crvril that rcl;i~t(rnrhip helween the p111iini11m Iltil- lion :~nd decrc;ire in the b;l\c e.tch;rngc c;tpacit> ua\ l~ncur l o p;~rli'ular point and hcjond ha^ valtln Ihe h;trc ckch;ln@ cap:lrlty rcmaincd prflai. cally rtcedy. ('hi~ltcrjec and R;I) I IO!X) ;llu~ np~r tcc l dccrca*c In llic b;lre exchange cilpactly III' t l . m ~ ~ n t m ~ ~ r ~ l l ~ ~ n ~ ~ z h! r cpc ;~ t l lcrchlne u l l l l ~OIII- uont of pol;lr\lurn rhloridc.

5 WELI:ASE OF YIXEI) YOIASSI{~M IFi SOILS

7111 rc lc i i~ of fixed p l i ~ ~ s i u m in wils, lhough a controversial cuh~rct, i s ,IS prtat ~mportnna, t inn it dcterminc\ the hannful cllccl of puss~um and il\ ;~vittl:~htl~ty 10 plant\. There urcdikrent approachn to jtudy the ratc :~nd ~~icch:~ni.;m(~f thc rclc:tu of the lixhl and no~~.cxchanguhlc potur\ium from ~ l \ ;111d cl;~! mincr:~lf. The importanl one5 a n : (i) Cropping (prolonged cropl1111;); (ii) rqu~l~hrium with prolon donor (dcplelinn with :~cid of d~lrcrcnt c~~nccntr;~lion~I : (iii) Rt1c;rv with exchange resins : ( ~ v ) I.c;lchtng w~th salt soluticlns . (v) Preeipilaticln of u~luhle pot;t,rium With \ome ren- ~CIII\ , and (vi) Krkaa on dwinp.

Clr.~n~inndc (1914)and others have observed llra~ tired potasstun1 W;IT

p r ~ l v \oluhlc in weak acids. This part of'thc lixcd pota\siub mav he #\at- lithlc 111 {he plirnts. Studin hy Cornfield and Pollard (195?).ind1c:1t~I that elrctroJ~:~lys~s could rclcate 53 lo 100 per cent of the G . ~ n l ptasrlum from \ail\. Thc! cunr~dered this parl of the fixed potar,ium to be mtdcr.rtcl!~ auatlahk to crops. Chaminnde (1926) found in NcuhaueZ~ expcrtlncnt\ th:~t ahout 16 lo 19 per ccnl of the Gxcd plnstium could be rcmokcd hy ~ h c o:tt d l i n g r from the soil which fixed potarsium atronply when Ircittryt w~th pltils\ium salt under moist condition. Kulodny and Rohhin* (IPJO) reportal that l i x d potassium hy wyoming hentonitc war only \Itghtly axti- lahlc to tomntcws. Evans and Attoe (19481 calculs!ed thu oats grown in h!i\tclicrlich pots in ninc months rcmoved 24 to 17 per cent of the pul;~rsium whtch w:rs tired. AIIix (1949) cletcrmined rlial 7 oat crop, of l h i hcrd~ng r t i ig is two years rcmoved 78 to 9R per cenl of the applied ptas\tum from [he Maimc si l t loam which fixcd up to XI per. ccnt ol' the potarrium appl~cd :rt ~ h c rate of XI and I I! kg per hectare.

Mcl..c;rn and Simon (19581 showed that pitasrium fixcd by drying waq

I.~rpcly r i ~ ~ ~ v c r ~ t h l r hj cropping hut that fixed under moi\l cond~titm\ N;I$

not w quickl! t~vn~lahlc. The inform:~tion on the e l k t of ~ h c tlpe of ch) minerals in wilr on the relcaxofrhc fixed pt:rsr~umisconflict~ng. Monl;~nd t.1 a1.(1957) obscn'ed that potassium fixed by vcrmiculi1e end montmor~l- lonttc was avuilrhlc for pbnt gro*th but not of illice. Marel (1959) stud14 ~uitassium tir;ltion h) illitc, vermiculite and montmorillonitr and found thrl ptassium was held weakly by illitc. the most common pta$sium firing ~nincral, sntl might kcomc avoilablc even in soils of high firing capacity.

The fixation ant1 rcleur of pobrsium war studied by DeMumbrum and Iio~ivcr (195%) under moist and dry conditions with clay and silt size fnc- tion\ of illitr and vermiculite as seprate minmls and in mixtures. The illite exhibited continuous release of polassium on wetting and drying. vhile rcrmiculite exhibited little change with moisture conditions. The data oblained showed that pomium fixation and subvgumt release an rcvw

POIAS?lllbI AHI) AMOIO'IILIM EIXATMY 1% INDIAN U)IIS 41

sihle i f hoth illrlc (a r d c i ~ u mlncrult and v a m ~ c u l ~ ~ e ( u lixlnp nrlncr:rl) arc prercnl in the sptcm. I t we\ elso Ibund tllal I I I C ~ ~ ~ I ~ In c\c)ri~n~olt,lc po(;lr\iunr t t ~ ~ ~ k place on dch)dr.~tlon and rckcr$tun ~II' ~I;I\~IIIII t~ 111,:11 form on rcmol\lcrlng only i f r c r ~ l r ~ c ~ ~ l ~ l e I\ prewnt tn tho \OII and II~II 111 11,

ah~cncc. The pr<~hlem i\furtlicr ccrmpllci~lcil h) Ihc l.ia ~h.it no1 t111lt ~hccl,~. m~ncr.~l\ hdl the primary mrncr.lI+ .ll\rl relcilu nonsrch:~npa~hlc ~N$I;I\~IIIIII

Sen 1.1 dl. 11949t \lud~cd thc rle;l\c u f ncin-enchanpcahle litc,l p t ~ t ; l ~ - luni of Ind18n rcd und l ~ l c r ~ l c \oII, allcr \haking wilh one pr.r teal cllrlc .=id. The) found t t la~ the t111:tl arnounl 11f po(a\\rum In lilur rctccc\rt\c Ic.lching with c~lr ic ac~d b r ekcecdcd the anrount ofcxchungci~hlc pcrtaa~~alti .lnd In ur~irc slbil5 cven ulicr 4th cxtr;lctton on apprec~ahlc ;Inrrlunl ol' c\. cklngesblc pulwtum w.\\ lcli In thc n111,. Thu\ cvldence war, ps~~\n lcd of the crlristloll nl'a dcl~nl~r. ,IIII~ILIIII o f per~irt\~uni hy cltrtc ilclrl 1rn111 IICIII-

c\ch:tnpe:~ble portir~n The ;~siount vilr~erl Irom \oil to roll h u ~ atnlc IIII,, \olu~ioti cvcr) timr the u)~l with cnractcd wtllr acctlc actil. Irrc~pccIIw III IIIC prcrnGt iald amoutrt u l the cxch:tngc:thlc potasaturn. Tlw appls.~tlcr~r 111

nitr~~pcn and phr~\phal~c fcn~lt/cr\ ;~pparcd lo makc ;I Ii~rgr s tnt~un~ 01' non-c~changc.~hle pcita\,lum ~ v i l ~ l ~ h l c III rtcc crop.

Mch1:r and Sliah (IU5hd. h and t t rludlcd ~ h c rele:~u. ~ r f n~~n-crclritnpa~, blc ( l i \cd] pr,tanlum in the grrruilu, Aruri ;md hlacl wrtlr~n u ~ t l r trl' Wsrlcrr~ Indl;l The roll\ wcrc giver, a prcvrou\ pol;trrlum l iwllon trcatrnclll urllr drlkrclil quanlllter rlf prbt;i\\ium unil thc rclcax 111 non-cxchunpcdhlc prllcrk. tuln determined. Ilurlng IN-m~rnlh prlaci thc untrci~ml ~trrirdrr, kr?ri and bliick eltton \or15 liheralcd 2X0.2.W to 34 kg. 428 222 to 461 kg ,rod 5 2 5 to 533 L y 111' no~irxuhr~rgcahlc ~nr t r \ \ iu~n pcr ha rmpecl~vely. 'Ihe ~ l l , afh~ch had li'icd Inrge quantltic9 or prlta\rlum dur~ng pnta\rium trr;rlmenc\ ~ 1 \ t 1 I~kr . t~cd large q u a ~ i t ~ t i c ~ 'of pot.rr\tum. The hlghc\t q r ~ i t t ~ l ~ t ~ c ~ ,d,o I~bcrrvd-in p(;lr$ium l rw ta l ulll\ wcre 7K3.579, Kh4.211 itrrd IlKc kg pcr hecran for nortrr111 R~ori and bbck u)tloe %oils, rc~pcct~vel) during !$-month period by six cucw\ive leeching with normal amnubn!um acctnlr. Thr prankigc rcreledr of the fixed polasaium war of the ordcr 20.0. 7.4 and 7.7 in goradu, biorr and black cotton urlls mpcctively. Thc rclcau of non-exchanguble polastiurn war more whcn the wil, wcre kcpt in dry condition than in motat stale. The quuntitin ofnon-cxchanpblc pe,ldruum r c l u d i n Na+ Cat 11' and NH', wllc wa\ in the dccrea-iap rrrder. Skrilized soils libcrdted polaa\ium indicating tlral microb~ological faelor Wac not responsible for the relcax of non-exchangeable polauium. During vx cantinuour cropping o l bujri in 18 months on gurodu wll, the cx- changeable po~u.dum taken by crops war 123.310 kg pcr ha and non- exchangeable 528 kg per ha. The cxchlrngeablc potasrium dacreaud from 374 to 249 kg pr ha whcn plants actually extracted 264 kg o f polatsium. The yidd o f &hi was no1 a f l e d but the perccnlap o f po tw ium in plants dsmrd.

42 I. s. GREWAI, AND I . s. KANWAR

Hantrp (IVSB) invest~goted the releau oS fixed potassium from k w ho~lc hy lcachtng with ummonium acctatc. It was found that fixed pohuium war rclea\ed at an almort un~form rate nlier the first two leaching, The lcuchcd $oils wlicn ruhjcuted to nltcrn~~le fm61ny and thaw~ng d ~ d not \ h o ~ ally r c l c a ~ oS lixcd putasrium indlrating thnt licering and thau~np had i~rtlc or no cAic~ on thc rclc:l\e or fixed w)tac'iium I'rom rc~ils. Grewal and hawar (1967a) delcrtntncd the nrailah~l~ty u l the nattrc 6%ed and thc fcrlill- %er fixed potarrium In the Pucijab soil\. Thcj reported that rycf (Gruminc;~el ssdllnfl grown aaord~np to Neuhaucr's ~cchntque could uttlirc only 2.h pcr cent ol'the native liheil potasrium and 10.5 per cent oftkc fcrlilircr hxcd potar%luni. Duttu and Mukerjee (1970) \tudicd the exuhpnpe txhavlour of polnrrlum In the puti~sh brdrtng atncrals. They Ibuy that ag;llntl a parliculi~r cntracting matcriill, H resins or H-clay. thc dikrcnt miner;ll\ yicld K ' 111 thc order: B~ot~tc > Mioil > Microline. :

'Thc case w~th HIIIC~ the non.er;chinp.cable or fixed phsrlum can hc util~sed hy thc crops from a soil under equal condilionr air6 ur ic* with Ihe nuturc ol'the crops. Murel and VcneLamp ( 19.(51 obwrved Illat the poturr ium tiaed by the w l a Srom potassium Prtil~rer applsat~on *a\ ava~bblc to most a l thc plantr but not to pota~oc~. With the umc cro& thc uptalc or l i d pit~\,iani J r m d \ upon the soil conrlit~onr. Thc eadier $011 faulors rcvieu~d ~ h r c h influccict the fikatlon of potasalum in roaa are the ones which control the ;~v~ilabll~cy of the liked povas\ium to the plant\. In gcnerul, the ptusrium uptdLe in Ncuhauer'r and pot e~peritncnla is greater than ill a so11 under m~rmal cond~tiuns. For this re;lbon it IS very d~fficult to lind exact figure, l i ~ r the upti~ke of fixed pata\aium undcr field wnd~tlon\. Moreover oncc ~>o~;l\\ium gets tixed in the \oil. it is difficult lo dist~ngulth bctuecn the l 'rrt~li lerl i~td polussium and thcnat~vc nun-exchangeable p)tasr iuni so Ibr a\ !he p+t;\sslum rcleau ir conccrncd. I t ir genrrully bcl~eved that Scrtilltcr lid ptus\ium i, more available to plants than the netlve non.e.tchangcc.able potiinium.

Thc nun-rxchsngcahle or fixed potaaium a n be wnvtned into ex. chnngr;~hle potursium ~f thc l e d of the c~changeablc potassium in boils is decrcusd h) croppine or h) extmcting the cxchangcuble potassium with some exlracrantr. The rate which fixed plpssium can be converted into available form to meet the crop rcquiremcnts is an imponant factor which determines the pructiwl aspect of this phenomenon. The nature of potas* ium fisatiun and i h rate d rebx depends upon the potassium status and the nature of the clay minerdl present in tbe soil. I t is considered that many soils have the capcity to fix large quantities of applied potassium which is not readily arailuble to plants but this h t i o n also savm the leaching of applied ptasium to the lower layer of the soil profiles. The availability of fixed potassium to planls requires thornugh invtstige~ions for predicting the rcspunrci of the crops to the applied potassium.

TIII. phc~~om~t~un of p ~ l t i l r r ~ u ~ ~ ~ liratios In wll, ib o l ' g ~ . ; ~ ~ pr,tct~c~l Import. anw ;I\ it plitjs an Imporldlil role 111 the polas\ium nkrlrtllon (11' tl~c pl:lnt\ and thc econom! of the pota\\lun (irtilltcn I1 IIII, oh\c.rvnl h! the an11 icient~\t\ and aha h) the iigr~eulturi\lc thnt romr pota,rluln dctict~~it soil\ rhoa a poor re-ponw to porarh I'ertill~rn. 'I'h15 ma) l v tluc tin l l~c l i ~ g l ~ lioki\\Ium liration c;~pi~c~l~es of [how 5011s. A \ revicwetl 111 ('~I:IOICI 4, numerous invcatig.~tioo\ harc hcen carried out 10 stud! the h:lrnlljll ellect of poktssium liriltlon and the avu~lsh~ltty of [he lihed pi1aulu111 to pl.~nt\ but the rcrults \dry w~th the type of the 5011 itnd ~ h c liitturc 01' !kc r r q i It is considered th.tt pot;lr\runi liiatton ln a nidcr;ite degree 111 cerlilltl \o~l \ ma) no1 be h;~rmful a? I! lu.romc\ a mean\ for holdlnp the ;lppllrd ~~I~.I\\I~IIII

ay;lin\t 1e.lching. Hut i f the pota\rtom liral~on wp:~c~ttc\ of tliv \IIII\ ;ire

h~ph, then hr,~vy doses oI'pot;irriun~ Scrt~ll/er arc requlrcd flu tliv ~~pttnntln crop productiu~i rc\ultllig into rlre In crrst ~rl'crop prtxluctlrrn ;111d thc t+;l\t;lpe of potsr\lum fcrulirer.

The r u ~ l factorr, >uch a* l y p 111 the cia! mineralh, Icmpcrdtllrc, II~III~.

turc ctind~~lons, pH, ekcl~mgcablc caltilnr, tcxturc and orp;rsc 1n;ittrr ,trc ltkely to knflucnce the hehaviour ofthe potarrlum In wlls ant1 11s uptilhc h, the [il;lnB Tl~c elfecl of the* factor5 on the l iullon of pola~r~um 111 u~ l l r and cia) mineral\ i\ dirur\cB In ('hdplcr 1. Scmc of the* f:rctlrrr c;ln hc modified to increalc [he aveilab~l~l)' of pcrt.lr\ium in prohlcm \I,II\. A few pocnt\ ol' pract~cal inlpurtan~c relalerl to thcu fucton arc ~CII~IUIICJ bclow :

I t 15 con+tdered thi~t the uctlvl~y of potawum ions I\ vcry low In 01111+

whlch 6% potaaslum rtrungl) One of the nrsqucnces of rbl* I r iw ;~clrtlty is an un,u~uhle rdtio of poubaium lo other cations. Thls ratio I$ u~lf:~rltu. rable for the healthy growth ofthe crop. Thur the roils uhlch fix potu\6ium btrongly are very likely to glve poussium deficlmt crops. I t ha$ brcn ohrcrb- d that an Dutch soils uhlch tix polasrlum rtrungly and have r poor rtrur. turc, the yield of the potato is low, despite a moderile pusdurn watcnt of the lei~vcs. There the poor soil structure may be the reiiwn for rcturdcd potassium upfakc as well a poor condinons for plants growth. Acti~tiun, temperature and moisture content of the mils have a great b r i n g on the availability of the potassium in soils. 11 has been found by a numkr of worken that higher oxygen content of the soil air and a hvourabk wl l temperatun inneased the potassium uptake by the plants. I t has ban reported by khu&n (1954) that in a wet soil the Ca/K ratio deercawd in relation to the same roils under dry wndilionr i n h d n g low availvbillty of pomium undu dry fonditiom. The agricultural cxgnicaa in Nelhcr-

44 1. S. GRlWAL AYI) J . 5. KANWAR

land alu) *bowed that the ctTect\ of potas\ium finalion were more pronoun. ced III drv years.

111 iidd~tlon lo thc ulil filclon, inllcrent plant tdctors arc also very im. p~rtnnt for the uptake of ~?iltr\\ium from the coil. The planta with rools of low cxchengc ci~p;lcity have a preference for the uptake of monovalent

ton\ l~kc K whcrc;~\ the plants with roots of high cxchangc capacity have a t 5

prckrcticc fur thr. upti~lc of divalcat ionr like Ca. The spcilic ad\orplion 01 ion\ hy d ~ f i r n i t crop5 IS alro tib\crved hy various workers, Ion uptake I, r very compl~catcd phenomenon wluted to crop and soil, i t depcnds upon the gcneri~l rules .{lid spxific proprties.

Tile placial wil\ of Finlsnd end Norway have $1 very hi* Cxing cnpacity for p~t:tsriun~. But In thcx countries somc harmful cda;ts of potassium fixuln~n hi~vc Imn bund on Ihc yield of crops. Appsrcntly6uficient poluss- iua~ mil) bc obtained hp (he pl~int roots in these soils fromthc silt fract~onr which conlrtncd ~~cathcrcd K &Idspars, h~otite and hydpbiotitc. Marcl and Vcndamp 1105.0 fuu~ld that in the high potassium fixing soils of Nethrrl:~nd:~ppl~icltion of300 to 400 kg K,O/haan take caw of the potassium ncrudt al'licld crops, such a, sugarbcet, mangolds, oats, llorlcy and whest, but 8 Itr 10 yean of potassium ~ppl iat ion at this rate is lleceslilry to take the optttnunl yeld of potiltms.

I'ron~ the bariou\ studies it can be concluded that fixed potassium ic not wholl! lost to the plantc, i t ir like a fixed deposit in a bmk which under fuvourahlc r.ondttion\ can bc mobilixd by thc plant,. Potassium liution lo .I ntder~tc dcgrec ma! cven be beneficial as it tend, to retain tempurarily the :~p l~ l~ rd pota\\ium III an unlcachahle state. In orchi~rds on heavy tcxtur- cd soil\, which fir potitasiu~n strongly, the applied potassium fertilizers ale mnutntriitcd in the top soil i~nd potassium is not leached into the subsoil. In thip ace rhc potils\ium is lost for h e plants and consequently large amounlr of potassium fert~lirrrs arc ncedtd. Under circumstances of unhvourahle ion ratio and poor structure the potassium fixition can be detrimental k a u s c the response to potassium fertilizers is slight. Under these conditions it ma) be c~sier to c o r m the properties of thc soil, than to try to k~tisfy the K fixing capacity of the soil by poulssium fertilizer applio- tion. I f the tnatmcnt of the soil is not possible, the practical advice is to chanp Ihc cropping pattern. Crops with rwts which have low exchange capacity should be grown, us they can take up more potassium than the crop with roots with high excbangc capacity.

SECTION I I

AMMONIUM FIXATION

ALr!iouGti i t i s WCII known that soils can f i x cc1nridcr:thle amotlntr ufnmmc~. mum ionr but the pllcnomcnon ill amrnonlum tiutcun tlar not rrvt~tc.ti i t *

much attention ar potasrium or phosphorus litatlo11 In \ ~ ~ l l r McUctk l I9171 rccogniscd that under the molrt cond~titmr romc \ollr l i tr l l ~ppllcd i~mmonium in o form that could not he renovcd b!. alL:~l~nc JI\~III;III~II or cxlracuon ulth 10 pcr ~CII~ hydrochlor~c acid and thus hr~~ l tph~ 11it0 pr,1111t. nance the phcnomcnon of ammoncurn Rxatlon in \LIII\. Reccr~t tn\crttp;l. tlon hilvc shown that tnany roils contic~ning llllte, n~~~ritn~clrillunitc ulld rcrmiculite type\ of rl;~y minerali have thcabil~ty 111 l i t conrldcrable nmoulltr of ammonium and that the iimmclnlum lirutlcin CII~UCII~ tncrruvd w~th tllc depth of the \oil profile. I t ha> alro heen rcpwtcd trhat \ubrtant~dl pnrtlon ofthe total nltrogcn In troplul and Rotham\trud soil, 19 lield up In the I;lrnl of the Lkcd ammonlum (Rodrigucr. IYW: Rremncr. 1959).

Ammonlum lixatlon In tolls w u r s when cxdi~ngcahlc or uater u~l~rhle ummonium Ion, arc converted Inio a form that m ~ ~ n o t hc rcictl~ly ertractcd with a neutril u l t solution, such a* potar\iurn chlorldc. Th~r limn rll' ammonlum ir con$ldcred io he d~flicull) ;~vallilMc lor ~~~t r~ l i ca t~un ;lnd lor plant nutr~tiiin. Thc mahanism of i immn~~~um 6xlc11o11 III soil\ ~ceern\ tu he thc wme as that of the pota\\ium firation. The ammonium lonr repland lotcrl;~)er c:~tlonr ruch a6 culcium. mngnc$lunt, btc.. In the cxpandlng I~IIII. cc\ of the clay m~aerrls and that causer conlractlon ol' thc cr),tal lattlu., and e~llrdpping ol' the ~nlerla>cr ammolitum iotn. Thnc etilrappcd ammonium ion\ cannot be elrily replaced with other autntnr and ilrc a~nrldercd as lixcd. The clay mlncral, chiefly nrpcrnr~hlc for the ammonlum lixatlo~l are illite, vermiculik itnd muntmorillon~te. The sull\ chich f i x pota\\ium wn alu, fix amtnonium. Standford and Pierrc (1947) fcrund n posttlve hlglt currelalion hetween the ptabsium and ammonium Cxiltlon ciipiicltleb of Weh5ter silt clay loam roil (U. S. A.) under thc maid conditions. The aval. lability of the fixed ammonium lo n~trifylng bateria IS of fundrmrntal imporma and has been studied by a number of worken w~th wnflicllng mults. Greual and Kanwar (1%7a. b and c) found that the ammonium lixation capacity of the Punjab (India) soils i, also quite high and Illere ir an appreciable amount of native fixed ammonium in thcx wils. Moreover the availability of native and fertilizer 8 x 4 ammonium 15 alw q u ~ u low.

The impomnce of the fixation and releirv ofthcammoniau~l nitrosen i n soibis increasing with the rapid inerase in the uw of ammonhl lcrtilircrr or tbe organic fertilizers whicharc m i l y convertdinto ammoniwl form in dls. Tbe studies carried out by tbc viviou, workers on thne spec& needs to be critically aramiPcd to make the brst UK of ammoniaml nitrogen for the pknt pwtb.

In ~ h c prcwnl \lud) ~ h c work done on the variou\ aspects o f ammonium Axation with part~cular rcl'crcnce lo the lndlrn soilr is discus& under the following hc;id\

I Arnrnr~nlaci~l n i~ r t i gc~~ rlulu\ and dewriplion o f Indian soils.

! Mechanism (11' ;~mmonlum 8r;111on in a0115 and the ammonium fixntion capactly or lndiun soils.

3. Fact~~rr ;~lli.cting ammonium Sxalion In rolls.

4. Htlea\c (11' fixed 81m111onium from the ulils.

5. Procticiil <~gnlfialnce of ammonium fixalion in sQils.

8, AMMONIACAI, NITROCK.N STATW IN INIlIAN SOIIS AND ITS DESCRIPTION

THE tot31 nitrogen content of a011 depends on uvcr:rl factor\. \tach a\ temp. rature, rainkill, so11 Iexlurc, type or Ihr c1t1) m~ner,rl prc+c~ir and vcgelstr~in. In Indla. most or the \orlr :Ire Ill* In tatul ~ind irv,i~l,rhlc rlllrttactl irnd r t

ir conridend to he the lir\t lirn~ting nutrlrrlt h r rropr ~ICIUII III J~Iknnt regions of the country.

Nitrogcn In sorlf, is m:~inly prcrcnt in oryunic I'iirmt. \uch ;I\ protan, amlno nc~dr, chitin. purine\, p?rimrdrne\ :and ~~trclcrr ;lrldr ~ l i ~ c h ~n dwttm. position givc r i x to ammonlilc;~l nltnigcn. Thr ammonr:icLrl Iutrogcn i s ul\o applied to the soils in the l'orh~ ol'I'er11l17err The i~mm~in~:~c.~l nrtrtinen on nitrification forms nitrrte nltrngm in tlic rorI\. The IIrtrillcI :Ire 1111 dr\rolved in soil solution and are rcadilj ar;tilL~hlr lo ihc pl.~~it\ hut the imtiunt of nltrate prctenl is gncrally \mall. Thc irmmon~acal nltrcbpcn rs held on lllc soil exchangc complex. Many roll\ ca 1 hold amnioainciil IiltroCren ro ttnit. ciouhly that il i c relc;r\ed \lowly lo mrritrrirp~nism\ ;~ntl plan(\. Thu\ the ammoniacal nitrogen can he dibided inttrc~cl~rnpe.~hlczlt~mos~um wh~ch Ir readily avallahle to plant\ and fixed ammonlcrm vhrch I+ slorcl) :rvi~ilahlt to plants. Rodrrgucs (19541 rcported that In the prntile \irriiplc\ or troplc;ll soil, 14 lo 78 per cent nitrogen war in the Tctrm ciTlixctl itmmonlum. Steven- son and Dhariwal (1959) dctermincd the natur;tlly fixed iimnltlnlum rn thc representative profiles of several \oil groups whrrhdid not rctervc any ammonium fertiliren. The amount of lixcd ummonlum In subsoilc runged between less than 0.05 in. e. per 10 g in pod/~~lrsnd grt~und water prdil)ls. and greater than 1.5 m.e, per 100 g in pray hrown pcd~r~lr wrih rnlcrmcd~ate values in grass land soilr, brunirems, planotolh chcrnoicm and chfflnut roils. The amounts fixed are related to Ihc amount iind krnd of Ihc clay mineral present rather than to the conditions of dra~nuee and leaching. The amounb of fixed ammonium in rurrace a i l \ were rmrller than rub soils. The pcrcenlage of nitrogen present as fixed amm~in~um was greater in cropped roil than in uncropped one. Brmncr 119591 obuwd in Rothamstcad soils that on an average 5.6 per cent of nitrogen in the surface and 21.5 per cent in the subsoils was in tile form affixed ammonium. Thcsc studies indicate that considerable amount of nitrogen in roil$ a n occur in the form of tixed ammonium.

In India very littlc attention has bai pa~d lo lhrr asp1 of wi l nilrogn. Thc available information on this aspect in Indian toil* is d iwusd in thc following pgcs. Kaushal and Verma (1967) dncrmined the amount of naturally fixed ammonium in the alluvial and mcd~um black ail profile of Mldhya Pradcsh. This fonn of i~mmonium ranged from 0.52 to 1.29 ma. p 10D g soil. The naturally C a d ammonium war more in the subsoils of

ull tbe pmfi lc~ +~udted e x n p only oae. Thr delltiled resulls an givm in Tilhle 34.

+ O~PA~IIC Pwd NH,

L ~ x u l ~ o n I)CIIIII SU~IIYC csrh)n (n1.e. per pH per cent cent)

(ircwal (1964) and Grewal and Knnwar (1967a, b 8pd c) dctcrnlined the total nitrogn, rvrilnble nitrogen, nitrate nitrogcn, mchnngcablc and fixed urninonturn In 23 Punjab soils. The dtlailcd results aft pivcn in Tables 35, und 36.

hrrmr of nllmyrn N/100 1 WII Rrcenlr@c of total nltmgon -- - .,-- R.lngc M w n Ranee Mciln

Tornl nilmycn 22.9 to IM.8 51.2 A\.z~iluhk nitro#cn 3.78 to??.U) 5 11.67 to 37.08 18.74 Nttrutc nirm8en 0.w to 2.70 0.19 0.12 to 4.98 I.# E~chnnycablc NH, 0.M tn 3.00 1.12 0.97 to 4.97 2.40 Fitcd NH, 105 to 6.85 2.66 2.20 lo 10.68 5.49

TARLF 36. IVTFRRELATIONSHIP OF DIFFERENT FORMS OF NITROOEN IN

POWAS wls

Eshangc- Fixed Anilabk Total Clay Forms or n i t m abbNH, NH, n i t m ~ m n i t m m prrirntage

Nitntc n i t r w n *chuycrbk NH, Fildd NH, , Aniiabk n l t r m Total n ~ w a

POlASEIUM ASD AMMONIUM .lltATION IN INDIAN WILL 51

The exchnngtable ammonium content of the Punjub wilr r a n d from 0.50 to 3.0 mg N with a mean value of 1.12 mg N per 100g,oil. It form4 0.97 to 4.97 per cent of the total soil nitrogen with u meun r111uc of :.a p r ant. The f ixed ammonium content of the* snll\ riln~cd hrtn 1.05 to 6.85 mg N with a meon valuc of 2.66 mp N p r lOOg boil. I t ftrrmcd 2.20 to 10.68 per cent of the total soil nitrogen with a mcnn valuc of' 5.49 y r cent. The tixed ammonium had signiflcitnt po\itlve correlrtion wlth the exchilngcahlc ammonium (Fig. R) and thcclay content ~ r l ' thc mil\ (he. 9) This indicates that exchangeable and fixed ummonium arc ill qu~l ihr~um with each other and clay is the main scat of fixed unimonlum Chauhun and Singh (1967) reported that the black roil of lndore nnd the alluvtol u~il of Gwalior (Msdhya Pradcsh) contuined 1.74 and 1.63 m.e, per I(W18 o f ~ialurnl. ly lixcd ammonium. .

Prasad cr a/. (1970) determined the difcrcnl forms c~fnmmnniacal nilr+ gen in the sedentary and alluv~al wilr of Isihar. Thc rhullr arc prvcn in Tahlc 37.

T A B L ~ 37. FORMS (IF AMMONIUM IV RIHAR VJII~ . . -. --- . - -. . - - - - . .-

Forms of ammonium Alludal Scdmrary Man wiln WII,

Walcr wlubk m.e. p r cent.. . . 0.016 0.047 U.M7 Elehongclrhk m.c. per anl . . 0.203 I 1 l . l O Z N~rive Rncd rn e. pcr cml . . O.M2 D71c 0.670 Noncxchan~abk m.e. per ant .. 0.6115 0 (115 0.652 NHNO, wlubk m.e. per an1 . . 0.928 U.Wt 0.MS Watcr wlubk p r an! o l tolal N ' 1.1 1.1 1.1 Ex~~han~~Mepncenloflotalnilropn, . . 4.5 4.2 4.3 Narin fixed per ant of total nilrpm . . 14.1 1T.V 15.0 NHNO, wlubk perant oflotnlnitrapor .. 20.8 1U.H I9.H

. . . . . .-. . . . - . -. . . . -

The alluvial and sedentary soils did not differ much with rnpect to various forms of ammonium. Thc water wluble ammonium vt~finl from 0.01 1 IO 0.103 m.c. per an t corresponding to 0.2 to 2.5 perccnl of the total nitrogen, the averalp values urn 0.047 m.e. per cent or 1.1 p r cent of total nitrogen which war equivalent lo 18.8 kg N pn hectare. Exchangcahlc ammonium ran@ bawcen 0.036 to 3.53 m.c. per an t with an average value of0.192 m.e. per ant. I t constituted 4.3 per ant of the total soil nitrogen mmponding to 76.8 kg N per h a r e . The fixed ammonium in lhex wils varied from 0.425 to 1.29 m.e. per an t with an avmr value of 0.676 mr. per ant. It f o d 8.1 to 20.3 per cent of the Wl soil nitrogen with a lnan value of 15.0 pm a n t oomponding IO 270.5 kg N per heccaw. The aon.&~ngabk ammonium amlent fan* from 0.448 to 0.972 m*.

I. 9. GREWAL AND I. S. U N W U

WTilWlUM AYD AMUc)YIl!W FIXAl"I0N IN 1NI)IAN Wl.1 53

per cent with a mean value 010.652 m.e. per nnt. I t compr~ud 1.U.4 LF N per hectare, The native f i x e d ammonium was significantly mrnlutd w~th the organic matter. total nitrogen, normal nitric acid wluhle nmmnnium and the ammonium fixation wpncily of soilr.

Thew preliminary 5tudler indicate thnc considcrublc nmounc rrl nifrlipen in Indian \oilscxirtq in the Form oFfixedsmmanlum:~nd 11 ir incrcu~~np W I I ~

the use of higher dow, of ammnniacal Fert~lircn or organic mitnurh 'Ihc nvn~l:~hilil) lo planlr OF th1.i form of ammonium In % r r ~ l I\ douhtlll. I 1 i, of practical impart:~nce to fir~d the amount\ of liwd ilnlm~rnium III d~llc- rent cyp\ of roil, and the av:lil:thtlity 01 fixed ammonium ca pl;~n~r.

9, XfF,CHANISM OF AMMONIUM FIXATION IN SOILS AND THEIR AMMONIUM FIXATION CAPACITY

M I S , hanimi of om~nnnium Qsarinn in moi1.s. Thc mcchanivn olammv. nium fini~tion ~n \oil$ and clay mincralrap~nrs to he thc rame as that ~ ~ f t h c pl>lil,rium fixallon. Stuntlfclrd and Plerre (1947) found a iipniticant correla. tiof1 ctvliicicnt or 0.87 between the am~iionium ;inti pOt:~\~ium tixrtlon airdcit~c\ of Wcbder IU. S . A,) high lime soils under moist conditions. Prior fi\;~tion 111 the ammonium or pota\sium had a dcprcnfinp clfcrt on the \uhxqucnt fixation uf the other cations, LC., NH, or K.i Crrev.al (1962) tllro rrln,rtcd a highly \ignilicanl posilive correlation (r 6.88) hclwcen the Flp~ariulil iind ammonium fixation capacities of Punjab roils (Fig. 10). Chiiuuhm and Singh (1067) rcporteci that the applica1ion of thc pcrta\\ium dccrcnctd the amount of nulurally fixed ammonium in dbe black roil, of Indore and i~lluvial aoila of Gwalior in Madhya Pradesb.

11 i s considered that ammonium fixation is a result c# the rcplnccmenl of cations ruch us calcium, magnesium, clc, in the cxpandnp lattlccs of the clay minerals by NH, ions which ~ u r m the contraction of,~hc crystal lattia nnd enlrapmtnt or the inlerlaycr ammonium ions not w i l y exchangeable and are termed fixed (Barshad 1948, 1951. 1954). T& expanding ~ypc of clay minerals likc vermiculite, illite and montmorillonitc are mainly responsible for ammonium likation. Wiklander (1950) concluded that ammonium ions having similor sue and valancy as potadurn ion$ showed rhc same behaviour nod were fixed in the normal potasrium poiitions in the werthercd micuceaus minerals. 11 is considered that the hollows arc formed in 2 : I type of clay minerals in the moleculnr facer that encloses their inter- hyer space. NH, ions can casily penetntc these hollows because the width of thc ammonium ion is 2.86 A which corresponds to the diamcler of the hollowr formed hy the surface of Ihe ovygen atomr. The ammonium fixt~tion cannot take plnct in I : I type of clap minerals such as kaolin be- cnutc ammonium ions cannot enter the laltice and thcre i s no space to hold [he cations. Buswell and Dundcrbostel (1941) and Allison rt ul. (1953a, b) considered that in H-soils contining large amounts or or~anic matler, thc ~mmonium fixstion could take plna by formation of NH,-organic wm. plcx. The amount of ammonium fixstion by the organic matter may be of temparary nntun and is likely to bccome available to plants on the decom- position of organic wmplcxes.

Melhods for /hc drtc.rrninarion of fixed urnmiurn in sob. DiRennt methods haw been uKd by the various workers to determine the ammonium fixation capacity of soils and the naturally hcd ammonium in soils. All these methods are of empirical natun and are bridly discussed. IlcFord- ing to the basic principle of determining the ammonium fixation capacity of

roils the cations like K, Pb and CS cannot replace thc lird ummulilunl a, these cations contract the lstt im and thc other cations, ~uch RI (.(I, ~8 nod Na a n nplaa the fixed ammonium by expndinp the Intr~ctr.

Bower (1950) proposeda method in which knownamountr orilrnm~1111um are added lo a soil and the nmmonium not repliecad h) nornmal initar\ium chloride ir considered as fixed. hrrhud (19211 propc)rcd nn ull:~llnc dlrllla- tion promlure in which the ammonium salu:ated soil umplc i\ ~I\IIIINI etth sodium hydroxidc and a duplicale umple i s distilled with p~rlu\rium hkclrtb aide. The amount of limed ummonium I\ cukulntcd I'rom the tl~lkrcnrc hetween the amounts distilled by d i u m hydroxidc untl pcltalsiun~ Iltdro- xide. Allison FI a/. (1951) p roved a mcthcxl whcrcin the roil I\ ri~turdtcd

with nmmonium ions. and then frce and readil! e~changcuhle ammonium ions arc removed with nrirmnl pulrsium chlurlde roluuun. The ditTcrcnrr in the total nilmgen of the ammonlum trcalcd and control camples is conri. den<! fir lixd ammonium. Rodr~guer (1954) propoud u method for thc detcrminatinn of nulurally lixed fimmonlum In roll In lhls rnelhod thc %oil iu (n.alcd with 4 : I mlrture 0141 p r cenl I~~tiroliu~iric acid and 50 p r cent Eulpl~uric mid l i ~ r onc hour The ammonlurn In the cxtract i\ d ~ \ ~ ~ l i c d with alkali al'lcr rc.,i.~v;~l of hydrofluor~c acid w~lh wlphu~~c :acid. Ihe ammunium rclc.tml hg th~r mclhod i\ con\~dcreJ :I\ (ired ;~~nmonium, tlremncr (1959) con\lderctl t l r ,~~ thul mett~od mipht no1 rclcd\e all thc k c d amm~in~um from clay miner.rlr and was l~kcly lo cclnvcrt \omr ol' thc a@:lnic:llly bound roil nltrolell to ammonium nitrogen. He prc3poscd i111(1ther me1111X1 for the determ~~ralion of fixcd amm~in~um in wil. Hc c~in\~dcrd thnl the d~lle- rencc in thc umaunt of ammonlum rclea$cd from the \oil h$ treatment with normal hydrofluor~c acid 4 normal h ~ d r t ~ h l o r ~ c ;~c~d ;~nd the normal potass. ium chlirri Ic in the lircd ammonillm.

Anrrno~~i?tn 11 rotfon i.~~pcrr.ilr nf varh. The arnrnlinlem h l t ion c:tpacity of soils varlc* wi~h the method urn1 for its dctcrminarlon :~nd il is not dcaira- ble to compilre the nsul1.r reported hy v:~riouf worLers using different methods. In India only a few studies havc hecn curried old on thir a s p t In the purl hut with the increase in the use of ammonluni fcrtili?tr, thi, arpcct nmls more ilttention. Pnthak and Srivasta\'a (19h3) reported that nmmonium lixation capcity of Knnpur (U.P . ) soils icgainsl magnesium oxide distil- lnt~on varied from 1.2 to 4.0 m.c. per an t with a mean value of ?.I m.e. per ctnl. On the pemntage hasib. 9.6 to 31.8 p r an t with an average of 15.4 p r mnt of the adsorbed ammonium vas fixcd h! the soils. The cloy fraction of the roils lixrd the highest amount of NH, i.e. 7.5 m.e. per cent and contributed nenrly 6R.2 per rrnt of Ihe ammonium fixation capacir) of thew soils. The contribution of silt WPS 10 per cent and that of sand 18.3 per ecnt. The ammonium fixation by wnd hction was attributed to the ns&;nnotion of some clay minerals with the and purtich.

Gnwul and Kanwnr (l967a, band c ) studied the ammonium fixation capacity of 23 representative roils of the I! districts of efltwhilc Punjsb under we1 conditions by applying different wncen!rictionr of the ammonium ions from ammonium sulphate. The percentage fixa~ion of the applied ammonium ions district4x i s presented in Table 38. The ammonium fixution was lowcst in Kanpre district where the soils wen acidic in nature and i t was highest in Ambala district where the soil was clay in texture. The percentage ammonium fixation decreased wlth the increase in the applied ammonium concentration, but tbc total quantity of fixcd ammonium imascd with the i n o w ~ e in the applied ammonium.

Kaushal and Vem (1967) studied the ammonium fixation capacity of the alluvial and medium black soil pmfiks of Madhya Radah. I t

T ~ n u 38. AMHU~IUM HXAIIIJX CAPKIIY 1, PIINJAH SIIIS A 1 111IllR1\1

('OhCl hlH4IN)hS 01, AMMO)KlUM MlNY

. . . . . ...... -

Krnpra <i~~rd,~\ l tur tlmhlrrpur Arnba1.1 Jullund~lr Prlrdlr Kdrnal Ludhlrnr Arnrlrwr Rnhiuk tc~otcporr H~ rwr

IUI ppm h' ppm N I,O(Yl ppnl N :.IXitil,pn~ h . .

tpcrtcnm48c llt.lInnl

ranged from 0.X.l lo ?.NO m.c. per 100 g roil with a mc;ln vuluc ( i f 1.M) m.c. per l W g . The :lmmonium lixullon capacity was hlghcr In rubwilr 1ha11 In

surfacc so11\. The de~allctl r ew lh are gvcn In Table 39.

. . . . . . . . . . . . . . -. .

Bhrnd Suri4c.r. Alluv~al 675 l,55 S u h l l h!X) 2.M

Morena I Surlau 7,YJ 1.42 Suh\oll 8.W 1.Y

Morcna ll SurLcc 7.M 1.40 Subr I 7.70 1.W

Jattilpur Surface Mcd~urn Mack 6.W 0.M Suhwrfdr.~ 1.75 1.16

&I Suriacc 7 90 1.22 Suhrhce 824 1.40 ~.~ . ~ . ,- .-

Prmd e l ul. (1970) stud~cd the ammonium fiwtiun capacity of the alluvial and dentitry mils of Bihar. In alluvial soils the ammonium Bur- tioncapacity ranged from 0.554 to 1.710 m.c. per lOOg wilh a mean valueof 0.915 m.e.perIOO& It f ~ r d 15.8 to 31.5 per cent ofthc lwl suil n i t r w

W 1. 9. UREWAL AND 1. 9. U N W A R

wit11 n mean value of 19.8 per ccnl. I n scdenlary soils the ammonium Am- tion crpucity varied fiom 0.573 to 2.853 m.e. per l W g with a mean value o f 1.115 m.c. per 100 8. I t comprised 14.9 to 79.9 per ccnt of the local soil nitrogen with u m a n value of 32.2 F r mnl. The overall mean value of ummon~um Iixatlc~n in lhe\c so11 wns 1.027 m.e, per l W g soil which amount- ud t 25.6 pr cent of the total roil nitrogen. Ammonium fixation had a 3igniticmt porltivc correlation w~ lh thc organic matter content of the soils. hut hud no a,rrclution with Ihe clay conlent of the soils.

10. FACTORS AFFE(TINC AAlMONlllM FIXATION IN SOllS

THF ammnnluni f i~ir l lon in soil$ I\ ~nflr~cnced h) a numbcr ol'Ihctnr\. 'Ihc impclrvalil onel arc di\cussrd helow :

I ' 1 n 1 i 1 f 1 The n;llurc ~ ind :I~I~IUII~ of clug nlirlerul5 Ilrcrcnt III s1)llr are known to pl:~y iI domiwent role in iimmonnlm tiaallon, rlic cliry minerdl\ chictly re\pon\~blr I;lr am~nnn~um 1ix;ililrn in \oil\ ;arc II~,~II crpal~d. ing t)pe. The observi~t~ons ol'sclnle of the rclcarch !corlcrs on 1h15 l r p c t are a, under :

Fixation of ammt~nium by bentonite upc~n drying wil\ irhw~vucl hg Page and Baver (IY40), Jotfc :lnd Lcvi~ic (1947) and Hallway ( IYSb) hul la!

by Wear and White IIYSI). Hanway (1956) rcycirled !hut h c ~ ~ t o ~ i ~ t e dlrl not lix ammonium under wet conditions. Allison rrrrl, (1951) a~nclutled tllat ill the Harpter clay lo i~ni roilr, alnmorilum fixntion u~idcr molrt c~rntl~tlunr war due lo ~llite, whereas untler dry condition\ it war due to ho~b ~ l l ~ t c 411d montmorrllonile. Aornine and Wada (1952) reported that In thc I.ukun~;r andy soils (Japan) ammonlum tixi~tlon war ciluscd by r c r~n icu l~~c 111 inter. stratitied layer, of micn and vermiculite.

Allison CI ol. (1953a) concluded that the clay mlncrul5 c~IL'R) rerpon\l. blc for Ihe firation o f aninroniuln In sciila arc vcrmrcul~~c, m t~n t~n~r~ .~ l l t ~n~ tc and illite. Verrnicul~te rolls lixed nlorr. irmmosium under moi\t or ;llr dry conditcons, but whcn hcatcd, i l l~ tc soil\ ahsorbed more ammonlum ; III soil, where montmor~llon~te prcdomlnated, the iimmoniuni lixatlon v.~lue\ were about half o f those for illitc ,oil\. Alll$c]n a ~ i d R~lllcr (1'1551 l i~und that monlmorillonitc fixed 6.3 m.crammonium per I W g and ~ll t tc i ~nd me1:r- bentonite 1.0 m.e, ammonium per I m p whcn leeched hith normdl alnnlo. nium chlorrde solution and heated at 100 C. T h y concluded that h~gh liaa- l ion o f ammonium In many toik was due to vermiculitc and mon tmor i l l ~~ nitc formed from illitc as a result o f weathering and with accumpan)in$ lurr o f potassium. Hardn and Kutsuna (1955) cottcluded that ammonium fixation by residual wils rrom crystalline vhisls at Yolatahama W:I\ d w to degrdded vermiculite apparently developed from Ehlor~de during wealhcrlnp o f schist. Stevenson and Dhdriwal (1959) rep& lhal n;ilurally lited ammonium i n great soil groups was related to the amounl and kind of clay minerals present and order o f ammonium fixation war illtte ,. monlmorillcl- nite > kaol~ni~e. Grewal and Kanwar (IYh?a, b and c) attributed lhc ammonium fixation in the Punjab wit3 to the presence o f illite clay mincnls i n these soils. brad el 01. (1970) considered that montmurillonitc along with illitc clay minerals were mponsible for ammonium fixation in the black wils o f Putida (Bihar).

(ii) Anurr~nium Cmcen~ru/ion. The increase i n the concentration tlf NH4 ions i n soil solution g e d l y lads IO an i n c r w i n ib fixation due to

M) 1. S. URLWAI. ALil) I. $. KANWAR

mars nclion. Aom~ne (1951) round a correlal~on coefic~enl of 0.W betwen the fihed and ud$orhcd nmmi?nium h) roil, of the south cnrtern provinces of lapan. Allison far 01. (1951) okrvcd that under hoth the uct and dry cond~t~ons the amount of ilmmunlum fixation increased bul the percentage fixat~crn dccrcuscd when the ammtrnlum added to Harprtcr clay loam was lncreud, Harda and Kutruns (19%) repl~rted that under thc moibt mndi- tlons the Increw In tfw amount of ammunium added to Yahatahamn soils [Inpan) incrcarcd the fixcd ;~mmonium. Noolmik (1957) rcportd lhat in hci~vy clr) rolls the ~oti l l alnlnonium fixatio~~ increased and Ihc pcrcentag fixnlwn decreased w~th the Increase in concentrntlon of ammonium from I lo 40 m.e. pcr 100 g roil. Grcwal and Kanwar (1961a. b and c) studied the ammonium firatiol~ of Punjab soilr at dilTeren~ cmantrationa. Thcy okcrked Ih:~t total anluunt ofsn~mon~um fixation incr)used as the concen- trutli!n or Ihc applied ammonium increased but the pprcenlapc fixation of the appl~cd rrnmonlunl decrea*ed with the lncniise in IRc concentration of uppl~ed ammonium. Thc aberape values of 23 mils arc plesentcd in Tablc 40.

T A U L ~ 40. AM~IONI~JM PIXATKIN IN PUNJAR WIIJ ~1 UI~~ERLNT

CON~LNIRATIONS 0 1 AMMONIUM IONS . -~ .. . . .. . -. .. - -

Aninlnnlum Ammon~un, Ammonium ilppl~cd tixed f i x 4

(ppm N) (ppm N1 wrwnbgc . . - . . . . - - - . . - - . -. . - - -. - - -

They also reported that ammonium fixed in thcx wils could he fitted linearly into Langmuir's adsorption isotherm. where C was the quilibrium concentri~tion ofthc added ammonium in ppm, and X m was the ammonium fixed in ppm. A close relationship between ummonium and Langmuir isotherm shows that ammonium adsorption is the main cause of its fixation. The ammonium adsorption in turn depends on the ammonium wncentra- tion in soil solution.

(iii) I f i ~ r r i n ~ anddrying. The wetting and drying of thc soils aflcr the addition of ammonium salts is likely to influena the fixation and release of ammonium. The studies carried out by Allison n a/. (1951) indicate that the ammonium fixation capacity of the Harpster clay loam soils i n c d when the soils wereuir dried aner the addition of 1. 5 and 25 m.e. NH, per 1006 soil, under moist conditions theamount fixed was 37,10, and4 per cent nspclively of the added ammonium while on airdrying the fixation rose to 56, 26 and 10 per ant mpxiwly. Repeated wetting and drying did not

mlAUtUM AHD AMMONIUM FIXATION IM INDIAN 90115 61

further increasc the fixation. Allison r l nl. (195311, b) further n p n e d that five subsoils fixed I .6 to 4.0 m.e. ammonium p r 100 g on airdrylng und 3.1 to 6.3 m.e. ammonium per I00 g on heating at 100 C. Thc \oil% conbining high amounts of vermiculite pve the highest value undcr moirt ccrndlt~onr but when heated the illite soils absorbed thc moat of ummonlum, Alli,on PI 01. (1953a, b) ohservcd that ammonium liriltion cc~pilc~ty or vermt- culite was not markedly uhcted by alr doing or hy l~wtlnyl at IW'C.

Aomine (1951) rcportcd that the ammonium fixation In sonre \oils from south eastern province of Japan increased whcn the soilr were drlcd after treatment with ammonium salt but thc heuting herore nmmoniu~n treatment did not effect the hxalion. Similar results wcre ulro r e p o d hy Harda and Kutsuna (1954) Scrr rcridual mils derived from the cryshlllne schists of Yukatuhamn (Japhn). The* studied indicutcd that drying of the soils after adding ammon~um alts would incrcnse the ammonlum lixu. tion. I t is also rcportrd that v)il Lcatcd lo 200'C may loow its ummontum fixation capacity becau9e layer of aome m~ncrals at thi? temperuture may exfoliate and xparnte to such an extent ur to remain d~$oined. L~ttle work has been done on thi5 typc of study in lnd~a although i t has a great benrlng on the availability of ammonium fertili~ers to plants.

(iv) E.rcl~anji~ublr c.atinnr und ration rvrhaylr i'y(~ci!l.. Ammonlum fixation has been reported to be allected by the nature orthe cation\ prewnt on the soil exchange complex. Banhnd (1950) observed that thc ationx such as K. NH,. Pb and Cs a)ntracted the Iat~ica and werc less acccs\ible to displacing cations. On the othcr hand Mg and Ca uturatcd sampln of vermiculite in a dry condition expanded the lattices equivalent to about 2 layers of wakr molecules, where* Ba, L i and Na saturated samples expand. ed the lattices to a distance of about one laycr of water mokcules. The cations which expand the lattices are easily replaceable. Aomlne and Wada (1952) reponed that ammonium fixation ia boil8 satunled with d l t b m t cations dareased in the following order : Na> Ca z ti z Mg 7 B z H: Ha& and Kutsuna (1954) found that K, Al and H ionc application dccrcased ammonium fixation, Ca, and Ba and had slight cRwt and Na had none in the soils developed from cryrlalline schists at Yahatahuma (Japan). Nommik (1957) reported in Sweden soils containing high amount$ of vermiculite, the ammonium fixation decreased in proportion to the poWe ium application. The application of o lhn eations d a r e d ~ h c ammonium fixation in the following order H > Li > Ba > Ca > Mg > Na. Scngupta el d. (1971) reported that prior addition of polassium and phor phate deemsed the retention of amrnonircal nitrogen in alluvial mils of Delhi while in the acidic alluvial foils from Dinbata reduction was voiy litllc and i n the Pusa calcarious soils retention was either d a d or remained (bc same. The results were wnftrcned in the pot experiments.

Bomr (1950) rtportcd tbat fixation of ammonium by wmc mils d 5

62 1. I. OREWAL AND I. S . KANWAR

~ m i s r i d regions 01 California caused a wmsponding nduclion in the at ion exchange capacity. The neutral normal ammonium acetalc method lor the delcrmination 01 cation exchange capacity gave lower values when applied to soils which fix ammonium under moist conditions. Harada and Kutsuna (1954) also found that ammonium fixation was accompanied by reduction in cotion exchange capacity 01 the soils derivai lrom crystalline $chis& at Yahatahama (Japan). Pratt and Holowaychuk (1954) also obscrv- ed that ammonium acetate method underestimated the exchange capacity of soils and the barium chloride buffer gave exchange caplcity values which correspondd with the sum total of the enchangeable cations.

(v) Depth. Soil layers have bcen reported to diver ia their ammonium Axation camcity. Allison ct 01. (1953 a, b) found that @ ~ c tcxtund, non- knolinittc soils of U. S. A. fixed much more ammonium i8 the subsoils than the surface roils. The ammonium fixation cnpacity of 11) surface soil was 0.4, 0.7 and 2.1 m.e, per I00 g under moist, air dried and kating tnatmenb of soils respectively. The corresponding values for the aubsoils wen 1.7, 2.8 and 4.6 m.c. per 100 g. The bubsoil fixed about low times as much ammonium as the surfacc soils when not heated and abjDut two times as much when heated lo 100'C. Aominc (1951) also fourYi that in general ammonium fixation was higher in the subsoils than th4 surface soils of south-castern provinces of Japan. Brcmncr (1959) repor(ed that the sur. f a a roils of Rothamstcadcontuined 5.6 per a n t ofthe tohl nitrogen in the form of fixed ammonium, the corresponding values for the subsoils were 21.5 per cent. Pnthak and Srivastava (1963) observed that ammonium ha- tioa ulpacily of the cultivated soils of Kanpur increased with depth but the lrcnd in uncu l l ive~ soil was not consistent. The detailed mults are pre ecntcd in Table 41.

TABU 41. AMMONIUM FIXATION CAPACITY OF KANPUR S(W3

Soil typc Rrantd m.o.pucunl adf~rbod

lmmonium

. Cull~vated wil 0.6' 1.4 10.3 6"-I' 1.7 9.6 I I-2' 4.0 18.3

L Uw mil 0-6' 1.7 20.4 6 -4 ' 1.2 12.9 1'-1' 2.4 32.8

mASSiUM AND AMUONIUM FIXATION IN INblAN SOIU 61

K l ~ b r l and Vema (1967) observed that the ammonium fixation spa. aty of the subsoils w u higher than the suiface soils in the alluvial and medium black roils of Madhya Pradcsh. The lower ammonium fixatron in the surfaa soils might k due to the presena of ammonium and polarrium ions already fixed in the clay minerab and to the interfering organic matter.

(vi) pH. Nommik (1937) found that the ammoniumHan~~onm~rkedly decreased with the decreasing pH of the Swedish rolls contuning high amounts of vermiculite in the clay and silt frnctionr. Grewnl and Kanwnr (1967 a, b and c) also observed that the acidtc soil of erstwhile Punjab $om Kangra district fixed less ammonium as comprcd to the alkaline eolls from other arms. The low ammonium fixation in acidic wils is due lo thc presence of higher amounts of H and Al ioni on the exchange complex.

(vii) hxrure. Theclay frattion of the soils i s considered to k the out lor the ammonium fixation. Barshad (1951) found that Inrgc part of the ammonium fixation occurred in the coarser fract~ons of the soils arsoc~ated with vermiculite like minerals. Nommick (1957) reponcd that the nmmonium fixation was highest in 1-2 fractions of Sewdish mils containing vermiculilc in clay and silt fractions. Pathak and Srivashn (1%3) reported that clay fraction of the Kanpur soils war the main xat of the ammonium lintion and contributed nearly 68.2 per an t oflhe total ammonium fixation capacity o l these sails. The silt and rsnd fraction contributed only 10.0 and 18.3 per cent of the ammonium fixation capacity of these mils. The ammonium fixation by sand fraction was attributed to the arsoeiation of rome clay minerals with sand particles, The detailed results are glven in Table 42.

TABLE 42. AMMONIUM FIXATION IN VAMWS tWCTION8 W KANPUR W U

Ammonium fiutlon Soit 1ypc - - - -.- --- -- -

Per cent m.a pr ocnr of C. E. C.

I. Uwr mil Sand 0.7 3.0 Silt 1.0 3.9 C ~ Y 10.0 12.0

1. Unultiwtaf mll Sand 0.4 4.4 Silt 0,LI 1.3 ChY 6.0 1.1

Onwrl and Kanwar (1%7a, band c) obrerved that ammonium fwtion wu ~ ~ ~ p a r u l i v d y more in heavy iextured d h containing iUitt typc d dsy minds Ulm IIK light tnturul wilr of Punjab.

64 I . 8. GREWAL AND I. 8. KANWAR

(viii) OrganL maurr. Sohn and Pcech (1958) reported that someof the ammonium fixation wpacitie, of the representative New York soils can be attributed to orgnnic mntter. Prasild cr a/. (1970) found a significant positive wrrclntion ktwccn Lhc ammonium fixation capacity of the ulluvial and d c n u r y soil, of Rihar and their organic matter content. The ammonium fixation by organic mutter may be due to the formation of NH,argimic complex in acidic soils containing large amounts of organic matter. In mineral &oils thc orgttnic mutter may sometimes decreare the ammonium fixation by blocking the entrance of ammonium ions into the clay lattices.

(ir) Rrluriun rfanrmonium fjxnrion wirh purossitrm fipliun copacilies of soilv. Stanford and Pierre (1947) observed that the Webster (U. S. A.) loam, silt luan~ and silty cloy loum soils with pH 4.8 to 7.5possessed a rather definite capacity to fix potis~ium and ammonium. They round a significant politivc correlation (r. ~0.87) between the potassium and ammonium fim- lion wpacitiea of these soils when the ions were supdied in equivalent amounts. The amount of the emmonium or potarsium.Fxation decreased in inverse proportion to the amount of potassium or mmonium already fixed in these soils. They wncluded that ammonium *d potassium are fixed by the same mccbanism. Bower (19%) studied thainfluens of addition of potassium on the ammonium fixation in some soils of semi-arid rcgions of Cal~fornia. They found that application of ptassium reduced the fixntion of ammonium but the totnl of potassium and ammonium fixed was pmctically the some. They also wncluded that undct moist conditions the soils studied fixed these ations by essentially the $am$ mccl~ani~m. OrcwaI(1964) also reptlned highly significant correlation (r.z.O.88) between the potassium and ammonium fixation capcities of Punjab soil (Fig. 10). I t indicates that potasrium and ammonium ions in the soils are competing for the same position in the interlayer lattices and tho amount of their fixation depends on their concenlration in the soils.

11. RrlLrlASE OF FIXED AMMONIUM IN SOllS

THE practical importanct of ammonium f i~ i~ t ian Ilo in two c\pctq : (1) itc unavailability to plants as it determines i ts dircct ucefulnr\c to plHntv and (ii) prevention of losses of ammonla in leuchi~~g. Chnnllnadc (19~0) found that the clay colloid\ of soils fixod ammonium which was ~ n a v # ~ l ~ h [ ~ to plants and rnicrosrganlms. Bower(1921) reported thal 13.28 per cent ofthedifficulty of exchangeable ammonium (fixed) wn\ nitr~ficd untl 1.1 to 25 per cent was available to barley plantsgrown by modified Neuhauer's trchIli. quc in the semi-arid soil, of California. I t indicated that the p l i ~ n l ~ were unable to utilirr any fined ammonium In excetr of that mude wvilililblc by nitrifying bacteria.

Allison rt nl. (1951) reported that only 10 per ccnt of the ammonium fixed by the Harpster clay loam soils was nitrified The ammonium fixed under the moict condition was more available for nitrifiution than [ha[ fixed in the soils dried at room temperature or at IWC. Alliwn 1.1 ul, (IYjIa, b) reported that availability of the fixed ammonium to nitrifying backria in the representative U. S. A. soils varied from nil to 14.0 per an t with an avenge of 5.24 per cent. The lowest values were ohtrined with soill high in vermiculite and illite, and the highest with soils l~uving chiefly mont. morillonite. Millets grown in the green-how assimilated 7 p r crnt of the non-exchangeable ammonium that had becn fixed by air drying and I2 per cent of that fixed by heat. Allison el 01. (IIH38, b) further reported that 5 lo 24 per cent of the fixed ammonium war available to nitrifying baac. ria. I t was lowest in vermiculite~oils and highest in montmorillonite ails. Allison eta/. (1953a, b) found that ammonium Uxed by the two vermiculite samples was available to nitrifying bacteria and in the third ample only I I to 16 per cent was nitrified. The cation ex~bnge capacity wac not an important factor in determining the rate of r c l w of the ammonium to bacteria. Allison and Roller (1953 a) observed that presence or potassium ions on the exchange complex reduces the nitrification of fiwd ammonium in montmorillonite. Aomine and Highashi (IP53a, b) observed thnt only a part of the fired ammonium in Japan soils was recovered by rice and wheat crops, its degree of availability depends on the kind of roils and clay minerals. Nommik (1957) found that in the heavy day aoil (pH 6.4) only a fraction of the fixed ammonium was available to nitrifying bacteria, etpaially at low ammonium saturations of the soil. Wal~b (1959) olmerved that in Wiwnria soil., the naturally fucd ammonium was unavailable to nitrifying bac&ia but subpequmdy fixed ammonium was n i t r i f i . Very little a&ntion has been paid to the availability of fixed ammonium in Indian wile. Gmval and Kanwar (1%7a, b and c) reponad that nivifieatioo of tht Gxcd w o n i u m in Punjab soils was of tbc ordtr of9.4 per cent and iu

66 I. I. O ~ E W A L AND I. S. KANWAR

avaihbility to rye mdlinga (Neubauer's technique) was only 9.2 per cmt The nitrification of the na~umlly fixed nmmonium war 7.33 per cent and iu availability to rye Kedlingr (Neubauer's technique) was only 6.46 per cmt. This indicates that rye seedlings can only utilize the nitrified ammb nium. The detailed rcsults are given in Tables 43 and 44.

TABLE 43. NITRIFICATION OF FIXED AMMONIUM IN PUNJAB BOIL9

TABLE 44. AVNLABILITY OF FIXU) AMMONIUM m rye WDLINL~NG~ (Nnrtuum's MPTHM)) ON PUNJAB S ~ L S --

Natiw Baed Fertilizer Uptrkeor UptaLe of NH,(w NllW AxedNH ~ t i v e fertilizer

Ssai~) ( m ~ NIIW'I f i ~ d NH, fired NH, soil) ( p r csal) (por ml)

The labomtory studis anid out by Gnwal (1964 ) rcveakd that only 70 per cent of tbe applied unmonium as ammonium chloride was nitri. 6ed in most of tbe Purijab soils and tbe m t s ~ s mvailsbk to ni-8

K U A . .UM AhU AMMONIUM P l X A l d N IN INDIAN SOILS 6r

bPctcrir. In the pot experiment studies with undy loam soils of Ludh~ma, Grcwal and Kanwar (1966) found that only 59.3 per a n t of the vppl~cd nitrogen (100 ppm) as ammonium sulphate was rcmovcd by t h m succms- ivc c r o p of paddy-wheat-paddy indicating that thc remaining nitrogen wnr fixed in the soil and that was not readily uvailublc to plant$. Thc stud~w rcporied above clearly ind~cale that many soils have the cspsc~ly to tia appreciable amounts of ammonium which is not readily avaibble to plants and the nitrifying bacteria. It will be of practical imprlana to And out the amount of fixed ammoniacal nitrogen nvailable indiffcrcnttypcn of bolls and the methods to utilize this nitrogen.

12. PRACWAL SICRlrlLANCE OF AMMONIUM rlIXAnON IN SOILS

NI~WEN is the most limiting nutrient for the production of crops and fruit t r m in the Indian soils. The application of nilrogenous fertilizers and orpnic manure in laree quantities lo crops is the recommended practice for obtaining high yield,. Since nitrogen fertilizer application is one of the costly inputs in crop production, its effective uw i s considered inevitable to decrease the cost of production. The studicc conducted Grewal and Kanwar (1%6) revealcd that only 59.3 per cent of the nitrogen applied as ammonium sulphnte at the rate of 100 kg nitrogen per hectab was recovered by t h m successive crops of paddy-wheat-paddy. Similar sadits conducted by other workers indicated that i t was not uncsmmon for 'f.ultivated crops to recover less than half of the nitrogcn added as renililea. Leaching of the nitrogen in humid regions and denitrificalion or volatili4tion of ammonia gas from alkaline soils in arid regions was considered @ be the major causes of low recovery of nitrogcn applied to crops. But tljc recent resear. ches in India and abroad clearly indicnte that the ammonium fixation can be one of the major causes of low recovery of the applied nitrogen in certain soils. Orewal(1964) found that nearly 20 per cent of the applied nitrogen as ammonium salt was fixed by the Punjab soils and was rendered unavaila. ble to the plants.

With the rapid increase in the use of ammonium Drtiliatrs to meet the nitrogen requirements of high-yielding varieties of different crops, the problem of ammonium fixation has assumed great practical importance. The retention of ammoniacal nitrogen on the soil exchange complex is considered beneficial as it prevents the nitrogen from leaching to the deeper layers of soil but the fixation of nitroeen in such a form that it is not released for the plant use is considend harmful. The studies conducted by various workers clearly indicate (hat many soils have large percentage of their nitrogen in the form of fixed ammonium which is inmsingwith the use of ammoniacal nitrogen fertilizers and manum. These soils also p o s w the capacity to 61 large quantilin or ammonium. The availability of the fixed ammonium is very low. The studies conductad by Gnwal and Kanwar (1967 a, band c) indicated that 6.4 per cent of the native f ind ammonium and 9.2 per Fent of the fertilizen fixed ammonium could be utilized by rye seedlings in Ludhiana (Punjab) soils, The availability of ked ammonium to plants depends on a number of factors such as type of the soil, nature of the clay mined, physical conditions of the soil and the crops to be grown.

From the practical point of view the main i n t m t of the farwr, the agmnomirt and tbe soil scientist is to i n m s e the efficiency of ammonium fertilizers. I n soils where ammonium fixrrtion is a problem, the &ency

of the ammonium fertilizers can be increased by prewnling the fixation of the ammonium ions or increasing the avsilability of the Rxctl ammonium ions. Very little attention has k n paid to this type of stud) in the past as low doses o f ammonium fcrlilizcn were applied in rolstion and thc hurm. ful eKcct of this phenomenon was not known. I t has k n oh~rvcd that the addition of potassium lo clay mincrnls inlcrfeml with the n~lr~fiation of fixed ammonium as it blocked the reledso of fixed ammonlum I t would be of great practical importanm to conduct the studies on the follc~w- ing lines :

I. Amount and nature of fixed nmrnonium in diflcrent type of nnilu.

2. Ammonium fixation capncity of diferent typy of roilr.

3. Availability o f fixed ammonium to nitrifying bacteria and plants

4. Methods to prevent ammonium fixation and to incrcav the availu. bility of fixcd ammonium.

Aomwu. R. R. 1960. Potassium Rxlt~on in wils. Sullr Ferfil., Hnrpn&n 23 : 314.78,

A L U U ~ O V , V. (1. 19%. Fixation and mobiliration of plash in s i e r m and carbmnte chtmozom. Sovlcr 1 : 33-42.

AUUON. F. E., DWSCH, I. H. AND R w , E. M. 1951. Ammonium fixation and availability in Harpctcr clay loam. Sull Srl. 71 : 187-ZtO.

- - - 1953a. Availability ofRwdammonbm in mils containins d i f f m t clay minerals. Soil 2 1 . 1 5 : 375.81.

- Ktfrwnr, M, and ROLLER, F. M. 1953b. Ammonip fixation in roils. Pm. Sol1 Sci. Sor. Am. 11 : 107.10,

- and Rnuea, E. M. 1955. Fixation and release of anllnllnoniwn ions hy clay minerals. Sol1 Srl. '10 : 451-41.

A c u w , S. 1951. The Rrrtion of ammonium in wils. I. *monium fuation of sonu 1oi11 in the wuth-wtem provinm of Japan. I. Srl, Eoll Monwr, T o k p . U : 81.97.

-and WADA. K. 1952. The Rution of ammonium in @Is. 11. Manner of ammonium Axatillnon. J. Sci. Soll Monw, Tokp U : 22740.

- and H-. 7. 1952. The Axation 'of ammonium in mils. Ill. F i n - tion of ammonium in Fukumo Mndy a i l . ;. Sri. SON Manm, T d p 22 : 315.16.

-ad WADA. K. 1953. The hution of ammonium in mib. N. Fixation of ammonium in homoionic soils. I. Scl. Soll M a w , T d p 23 : 1.4.

- cad H m ~ m , T. 1951s. The Axltion of ammonium In will. V. Availa- bility of Rxod ammonium to crops. J, Sti. $11 M a m , T o k p 23 : 105-8.

- . -. 1953b. The b d o n of ammonium in roib. V1. NiniGestion of fixed ammonium. I. Sri. Sol1 Manun, Tokyo 11 : IBM8.

Am, 0.1. 1949. Fixation m d mvay by oats ofpotuh applied to mils. Pm. Am. Soil Sri. Sor. 13 : 111-15.

b u , M. K. and VWTA h o , B. V. 1969. Studios on hution of potsrrium in roilr of M m r e $us. M y m I. wlc. Sci. 3 : 251.53.

k~aw, S. 1958. W* of Rwd p o w i u m from roils. J. I& Six. SOll Sci. 6 : 11-15,

BuuuD, 1. 1948. Vaninrlito ud itr mhticn to biotite aa m b d by lw excham E OM, X-my mrlm, d l h t i d (bamal ewa urd m t w coatcot. h. Mlwr. 53 : 65El8.

-. 19N. Wi of intahyw aUrm on tho uplaion of m i a typg of ml k t b . h. &I?. 56 : Z-38.

-. 1931. ~ h u c h u w i n m i b I. A m m o a i u m b t i w a n d i ~ R L t i m to

FWiASSIUM AND AMMONIUM FIXATlON IY INDIAN WlLs 71

h n u c ~ ~ l . 19% Cation c l c b w c in miuceuur minerals, I. Rrp lamb~l~ ly t b inwiayer u t i o m of xrmiorlite with ammonium and potaulu~l Ion,. sr; n : 463.72.

-. 1954. Cation cxehawc in micaemlu mincrah. II. RL~IPLVP~IIIO 01 ammonlum and p tau ium fmm vcrmicul~tc, blotitc rod muntnnr~l lon~~r. Id Scl. 70 : 57-76.

Bowm. C. A. 1950 Fiut ion o f ammonium IIC d i l u l t l y cxchan&ahk fomi undcr moist mnditions by l o r n nails of mi.arid regions. Soil k, 70 . 375.81.

--. 1951. Availabil~ty of ammonium lixcd in d ~ k u l t l y cxcl8any~hlc form hy mil8 of r m i r r i d regions. Pn~c. Am. Sol1 Sci. Soc. IS : II9.Y

BIIWN~~, I. M. IYSY. Dctcrmination of Rxed anlmonium In wllr. 1, u p l r . Scl. 11 : 147.60.

BUSWELL, A. M . md Dv~ommEL, B. F. 1941. Spa.lrwups $ludic# of b r x cr. chaw rmtorisls. I . Am. chrm. Sor. 63 . 2554-58.

CUAYINADB, R. 1936. The nrcnion of potssslwn In loll Ann. Atron. 6 : 8IW-30.

--. 1940. Tho Axntlon of ammonlwn.lon$ In a noncxchunyeahic h ~ r m h) thf clay colloids o f soils. C. R . 210 : 2H-266.

C U A T ~ I ~ P , B. 1951. Mcchanirm of p lash Bxatlan i n WIII .%xi f'ul!. 11 : 111-3:.

-and Rw, A. 1954. Potash fixat~on by clay mlneralu. J. l n l n S i ~ r . L i l k l . 1 : 63.65.

--A , - 1958. Bchaviour of H-mon:Mrilloniv on rcptntcd lrcalnlcnl with KC1 and desarurationr. J . I d i n n M r . Sol1 Srl. 6 : 7-10.

CHIUW. S. S. and S m . D. 1967. Elfcet ofrnur~raofpQlaseum on f ixd rmmonlm in m i b of Madhya Praderh. J. Indian Sur. L i l S r i . 12 : 257.59,

Cor~~lgo, A. H. and ID, A, G. 1952. Polu~dWn Bwllun in lolls Sludlcl hy ebetrodidysis. I. Scl. Fd. APrir. 3 : 567.69.

D A ~ , L. and hfurwn. S. K. 1970. Exchanp behavlour o f Fatalalum ion# in polash bcaring minerals. J. I&n Suc. S,III Sc1. 18 : 367.74.

Deuuuuuu, I. E, and H m , C. D. 1958. Potadam r c k x and flxatiun ab lcd to illilc m d vcrmiculilc as singk minerals and in mixturn. Pror. Anl. Soil. m. .br. t2:ZW-u.

h w m , S., P w r . 8. L. and f i r n u n . M. IW. Audin on Ib forms of~olawi'Jm i n roil of Rajar(hm. J. Indun Soc. G I 1 Sei. I6 : 55.60.

EVANI, C. E. a d A m . 0. I. 1948. Pmutium l u d y i w C K ~ Of VlrPin a d c r o w mih Scit~vc, N. Y. 66 : 3U-34.

heu, W. md e+s, 8. S. 1918. Cadit iom of f e n i h r ~ t l h midm in sik loam roils. I. agrk. iln. W : 59-81.

mwu, I. S. 19M. p o t w i u n and ~ n v n a r i m Fiurrloa in pylob solbe Ph.D. 'Ik&. Rnljlb Unit., C b o d i w h , W b . - 19661. Form, of in Rvljab wih. I. Indiarr k SCd 3%. 14: nw.1

72 1. s, G ~ A L AND I. S. KAPIJAR

OWAL J . 8. and KANWU, J. S. IWb . BOJUvmur of ommonium f r r t i l im in will. I. Rra, P# qrk. Univ. 3 : 34549.

, --. 19678. Potpraium hation in m m mils of Pqnb, Haryans and HilmchaI Pradwb. I. lMon SN. SUN Srl. 15 : 23744.

-, -. 1%7b. Ammonlwn h t i m inPhab soils. J. Rrs . Pmjab agric. Unlr. 4 : Id

- , -. 1967~. Fonns of nilropm in Punjab milr. I . Rrs. P~~njnb rqlrir. Univ. 4 : 477-80.

HANWAY, J. H. 1956. Fimtion and rrka* of ammonium in soils a d nrtain minerals. /ow Sf. Coli. I. Scl. 30 : 374-75.

HArur, T. and KunuuA, K. 1934. Ammonium h t r o n by residual 4 s from crysfalline schists II~ Yahtahnma. Bull. mm. in$(. ugric. Sci. T o k p 30 : 11-41.

Hasan, H.and Valnyutharn, M. 1971. Fitltionoiphosphatcpnd potglumas influenced by roil typc Madm lyric. J. 51) : 613-19.

Hvnwnz, C. and BATCIMLJX, H. W. 1943. Sludier on biologicul f@on of nitrogen. Sdl Sri. 56 : 371-82.

JoPvr. 1. S, and Lsv1~6, A. K. 1947. F iut im of pot~sriurn in rr&ion to uchange wprcity of soils. II. Astociatiw fixation of other cations panic@arly ammonium. W Sci. 61 : IJIJB.

KANWAI, I. S. 1959. Two dominmt clay rniaecals in Punjab soils. I . Idion Suc. Sol1 Sri. 7 : 249.Y.

-. 1961. Clsy minerals in saline alkali mils ofthc Phub. I. Indian Sot. So11 Sr1. 9 : 35-40.

--. 1970. Pomium the kcyfaclor. I&n kg. 20 (3) : 15-18.

- and Onrw&, 1. S. 1%. Availability of Axed potasriwn in Funjab soils. I . Ra. Pu@ab qrlc. Univ. 3 : 101-4.

-. -. IWb. Relntiofmhip betwan Ion9 of soilpolaeriumandpanicIn aim. I . 1 h n Snr. Sol1 Sri. 14 : 221.25.

KARIN. A.C. M. B. and MULC, M. A. 1951. Polrrpium h t i o n in East Patism roils up& diRormt conditions Soil Sri. 91 : 29-38.

KAUWAL. 0. S. md V W , G. P. 1967. Ammonium tixatim in ~omt pro& aoila of Madhya Pndgh. I . N. K. V. V. RN. 1: 72-80

KwMm,O. 1887. &n& Verwhrt. 33 : 359.

K W r , S. S. and h u w , A. 1970. Patlmum status of mils oi Hisar dimin (HUYUU). I. h s . h&b W k . Univ. 7 : 17-26.

KouPm, L. and Ranem, W. R. 1940. Anihbility of Bwd poU.rium lo p h n . MI Srl. 49 : 303-13,

HA. K. md SKW, S. P. 1970. ?ho *&timihip behaa d 8 ~ 0 1 t f01~16 01- inm wd p i c k ma in d i i t roil group of Rajaah, I. b d h k. &I a. $8 ; UL-27.

POTASSIUM AND AMMONIUM FIXATION IN INDIAN UOIU 73

MARL, H. W. VANOU I95OL. Potassium l h l i on in Dutch soill : mincnloyn'al amlyur. Soil Scl. 71 : 161-79.

- 1954b. Fixod a m n i a in tropical soils. J . SnllScI. 5 : 264-74

-,and VENLKUIP. I. T. N. 19SJ. hlauium In Du ld urilr. Venl. Ixndb, Ondcr~. S. Gray, N. 61 ( 8 ) : 61.

- 1959. Potassium fixation is kndkcial soils chrrtcristic forcrop produr lion. 2. PJI. Erunhr. Duw. &*.I&. 84 : 5141.

MCLUN. F,. 0. and SIMON.R. H IY5U. Polauiwn ~ k a x nwi fixallon tn 0h10 ~ I I I I S

measured by cropplng and dcrmwl crtractlonr. Ohin q r r c . f ~ p SNI. Rt,. &I/. 824 : 30.

M~HROTRA, C. L. and SINOH, G . 1970. Furma of potassium In brord mil lrnupa or Uttar Prudsah. I. lndhn Sur. Soti Sci. I8 : 317.14.

MWTA, B. V. and SHAH, C. C. 1956a. Potasr~um r t aw of aoils of WnMm InJ~cr. I. Indian I . ryrlc. Scr, 26 : 193-M4.

-, - 1956b. Potaanwn stutusuf aoila of Wutern lndla 11. F I K ~ ~ I ~ ~ of potassium. lndian J. agrlc. Scl. 26 : 267.79.

- , -. lY56c. htas~iunl ~tatur of Weeldm indiu. Ill. Rckw of non. exchanpcabk polnsskum in will. lndhn 3. a r i r . &I. 26 : 279.92.

UISHRA, B., TOISATHI, B. R. and CHAUHAN. R. P. S. 1910. Sludier on forma and avil~la. bility olpousium in roils of Ullar YradcB. I. Wiun 6 c . Soil Srl. 18 : 21.26.

MULA, S. G. 1958. Adsorplkon and fiwlion of poladurn from pole~sium phwhutc undcr wet condilions. J. lndlm Suc. Soil Scr. 6 : 19.52.

MUM. R. V. and SHANUR, H. 197b. Pulasim slPUU of Ultilr Prrdcsh ioih. J. Idlan Sr~c. SOU Sci. 18 : 319-26,

MITRA,~. N., SAIIMA, V. A. K . and RAM AM^^, B. 1958. Comparmlivc atudic~on the p m i u m halion capacllie8 of Indian soils. I , Indian Sor. SUN Sri. 6 : 1.6.

Mom, N. S. 1959. PolaB 4lalvs of Nanjinad wil8. Madror wrlr . 1. 46 : 161.67,

MORTUND. M. M., LAWUN, K , and UCHUA. G. 1957, Flulion and cclrru of pow ssium by somcclay minerale. Pror. Am. SuIlSri. 9 c . 21 : 311144.

Mururn, H. N. 1955. Potasium in Iropibal wib. Indian PMalh rponwr arc 'upposed unmporuiw mil& detcrmincd by a m ledYricluc of apcrimall oo cultivntors frclds. pot us^. Symp. 1915. 219.91.

Mvrruol, H. N., MANDU. S. C. and Muutwt. 8. D. 1955. Pourb mpdc of B6sr wih. Pmc. B h r A d . WrC. Scl. 4 : 14042.

NANDY. N. K. 1946. MvlrZ of lime on w i l potah. Idmn J. q r k . &I. I4 : 4354.

Nmnr, H, 1957. Fwtioo and dofurtion of ammonium in coik. Acla Agrk. S@d, 7 . "US.

Ouruc~. P. K. IDID. lnvcrtigat~ons on the rope of rapid w i l lest for K in India u judged by their corrolal~on w~th crop nspnsr . Ph. D. Thesis. Bombay Univ.

p ~ u r , I. H. and B~vca. L. D. IW. Ionic size in relation lo fuationotcrl~oa bycollai. &I clays. h u r . Suil Srl. Sur. Am. 4 : IJO.55.

PIIIUL. A. N. 1954. Contr~hul~onb of mcchan~cal fractions of the soils and 11s o m i c mullet towards povdsh fixation. Madr~~r, a r k . J. 41 : 117-33.

Ammonium fix'dtlon in mils. K~IVUI agric. Cull. J. ZylO) :

-.-. SHIIEHAHUL. I. G. and MUKFAII, S. K. 19%. Potash flr~ngwpncity ofalluvial ao~ls, Cmrr. Sri, 19 ; 120-21,

--. SRIVAIIAVA. H. S. 1963. Ammonium Bxntian in soils. bra Univ. I. k,. I1 (Part 11) : 9-107.

----an'l SHARMI, K. N. 1963. Ellccl of anions on the mdsorpli* of polasb in roils, ~ f r u Univ. J. R,v. 12 (Part 11) : IJ3.58.

-nd V ~ R M A . K. S. 1967. Ammon~um flration in sorls (i)Effocl ofpcasaim on the availnb~l~ty ol'nitmgcn, Indian J. Sri. i d . 1 : 42-47.

Plrw*~,. R. N . SINIIA. H, und MANUAL, S. C. 19678. Fixul~on ofpotassium in Biiar 80lfs. J. tn~t . Chrm. (Indiu) 39 : 225.29.

--, -, --- l967b. Fractions ofpolauium in W a r soils. J. Indian Sor. Suil Sri. I5 : l73-79.

P a m ~ . B., SINIU. H. and Pu~uo . R. N. 1970. Forms of ammonia nitrogen in mils olBihrr. J. lndinn S'ir, SoilSri. 18 : 289-96

Pam; P. E. and HlKuwAvrnur. 1954. A comparison of ammonium nnlatc, barium nmtatc, and bulleercd barium chloride mthadr of determining cation crchsngc capa. c~ty. Pror. Am. Sur. Soil Sri. 18 : 36568.

h w r u ~ . P. C . , YEWALW. K. S. and SHRIV~AVA, M. M. P. 1958. Clop respone to potaah under lndinn umdilions. J . Indian Soc. Suil Sri. 6 : 29-46,

R~AKANNA, K, rr a/. 1970. Raintionship olsvailablc possaium wilh roil reaction, nvailublonltmgen, limeconten! andorgMiewntentsinx)iisofTamilNedu. MadrclF qr ic . J. 57 : 77-79,

RAu*mxwrw. B. and WAJ, 1. C. 1%9. Available nitropea, phospholus and potr- uim stslur of lnd in Soils. f ir t i l . Nnvl 14 (8) : 1.12.

-, Dsu~. S. V. a d RAYWUDHUII, S. P. 1952. Pouu im flulion in soils with spaial m k w to India. lnbbn J. g r i r . Sei. U : 4%2.

RW*N, K. V. and JACIL~~N. M. L. 1965. Mica c k a w marphololy c h l m durin# potruium nlear and furation. J. I n d b Sor. Soil SEi. 13 : 63-iU.

Rnrmusa, R. F. 1951. Soil potasrium. Adv. Agwn. 3 : 113-64.

Roomgun, G. 19%. Fixed ammonia in tropical wik. I. SoilSrl. 5 : 264-74.

~TASS~UM AND AMMONIUM flXATlON 1N INDIAN JOlU ?$

Rnucttrumu~~, S. P. and D A ~ A , N. P. 1964. Ab@vtu and Po(0t~iw1 S b w Q/ W a n SUUI. Indian Council of Agric. Rn. Review &rw No. 36.

hum, A. C, and h a , H. W. VANMI 19W. Po~uium RIYtion in so118. PUIPU. S y q . IYU : 157-201.

Sa,A.T.,Dw, 0.C. sndBae, S. K. IW9. PoUu1m1talwnnd8rvihb111ty toemp of noncwhanpuble potassium In mm lndirn md and lattritc wrls. svil S ~ I . M : 291.305,

S w u m , M. B., BnNwce. N. K. and CHANDA, H. 1971. The oBctm ufpotusdwn and phosphate retmtlon on NHFN in ~ o i h and it8 m w r y by wheel crop. I. Idion Soc. Suil Srl. I9 : 215.19.

S ~ N , J. B.andPw~, M. 1938. Rctcqtion of flacd mnoniwn bj wilu. So11 Sr1.M : 1-9.

SrANiolD, C. 1948. Fixation of potassium in wiia under mu111 cond~tionr and on dry. ~np in relation to the type of clay minerall. Prur. Am. %c. Gi lSr l . I1 : 167.71.

STANF~D, G. and PIURI, W. H. 1947. Thc relation orpotassium lLution 10 ammo. nium fiution. Pwc. Am. Suc. Sull Scl. I I : 1354.

SrsvNm, F. I, and DHARIWAL, A. P. S. 1939. Distribution of fiwd ammonium in soils. Pror. Am. Sur. SoilScl. 23 : 121.I25.

SWAW, B. N. and LAL, P. 0. 1970. Correlation studla a plant uptake o f ~ l t u i u m snddlintvalun. I. l&n Soc. SoilSci. 11: 17419.

TIWARI, S. N., SINHA. H, and WM,, S. C. 1967 . Pol~~:iwn in Bihnr roil^. I. l h n Sor. SullSci, 15 : 73-76,

Uwa,A.C.andDw,S.V. 1944. Mapofpotahdiutrilationin Indim, lunphl~stird).

Vmru,O. P.andVw,G. P. I W . Studinon avu~labllpota~ium in w~l~ofhfndhyr Pndcrh. I. lndjon Soc. SuilSci. '16 : 61.64.

Vw.,N. J. 1933, The formation o l muvwite in wib and rsfamrn~ in wih: gravity wparatim ofminerah, Am. I. Stl. l6 : 11429.

- 19M. The fut ion of poluh in dil&ullly r n i l ~ b k form in ~ i b . Suil Scl. 3l : 267.87.

Ww, J. 1. Pad W m q I. L. 1911. PWm Eul'ia, in clay mimrlt 81 rtkcbd to crysml annun. Soil Scl. 71 : 1-14.

W m , L. 1910. Figation of po&t!m by chyl lr l l l rald 4th diflmni C4b1. Sdl Sci. 0 : 261-68.

-, 1954. Po rn of potassium in thc roil. POW. S ) V . 19% : 109.21.

Wuw, L. M. 1959. Native &ed MmoPita sad fi*rdon Of b~~lbd mmkdum in r yqnl W' ' r i ,. qi :. ,46111. 28 : M W .

All Rights Reserved 0 1916 by the Indian Councilol.qpncultural Research, Hew Delhi

First printed, Sopmmbr 1916

Rialed inlndii by T. Duni at the Diaapn P m , P.B. No. 4%. Vepn. Madm and published by 9. S, anal, Under Bsmary, for cbe ladin council of

AgrMtunl RaurJ Now Dolhi

rc potassium and ammonium a fixation in indian soils

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