Potassium Fixation in Hawaiian Soils

·:POTASSIUM J'llATION IN BAWilIAB SOILS

DNIVERSITY OF 1IAWAII IN PARTIAL NL1lLUIJffl'l' o, '!'BB REQUIBBMBlff.S FOR THE DEGRO OP

JIAS'?ER OF SCI&KUE JUBB 195)

By Harold Haruo Bagihara

TABLE OF CONTENTS Page AC.KN'O\VLE00~1'.1T ••••••••••••••••• .•••••• • • • • • • • • • • • • • • .• 1 LIST OJ' TABLES • • .••••••••••••••• •-•••••• • •-•• • •• ._ • • • • • • • ii

UST OF FIGURES. • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •..• • • • • • • iii INTRODUCTION•••••••,• • •.• • • • • .• • • • • • • • •.• • • • • • • • • • • • • • • • • l

DESCRIPTION OF SOILS USED••••••••••••••••••••••••••• 3 METHODS OF ANALYSIS...... 8

EXPERIMEN'l'AL Potassium. Fixation Upon Moist Storage...... 9 Potassium Fixation Upon Air-Drying...... 17 Potassium. Fixation Upon oven-Drying Humi.c Latosol...... 21 Potassium Fixation Upon Alternate Wetting and Drying. • • • • • • • • • • •.• •.•• • • • • • • • • • • • • • • 23 Eftectcof' Potassium Saturation on Fixation and Exchange Dapacity...... 26

Dift'erential Thermal. Analysi .s of soils Used..... 29

GENERAL DISCUSSION•.••••••••• •••·• ••••• • •••••• •••...... 39 stJAltlA.RY ••••••• •-•••••• •-••••.-• •••• •-••.•••• • •••••••• • • • • • • 44

LITERATURE CITED••••••••• •-••••••• •-••••• •••••• •...... 46 1

ACXNOWLEOOEIIIUIT

The author wishes to express his sincere appreciation to Dr. G.D. Sherman, Chairman o:t' .t-lje 'l'hes~s Committee, and nr,tfl•S• Ayres for encourage~nt, soggest1ons, and ht,~}\ful. oritieism. "'id\.v"'.-: ;: ef~*,.~;;_· ,,, {~~,'Y'? T:be author is also grate:t'u.l to the H. s • .P. A.

Expe,rimBnt Station where experiment.a of this study were e~rrled out. 11

Page

Tabl,e l. Some Propert.1es of Soils Used...... 6 Table 2. Ett'ect ot Air-drying on Flxation or Potassium 19 Table J. Ettect ot Drying to the Wtlting Point on .Fixation G'f Potassium. in Low Bumic Latosol (Nl) Soil 11o. 50-225...... , • • • • • • • • • • • • 20 Table 4. E:ffect ot oven-drying llumie Latosol Soil Bo. 49-35 on fixation of Potassium...... 22

Table 5. E.f1'"ect or Alternate Wetti,;g &. Drying at Room Temperature on :rtxatian or Potassium.. 25 '?able 6. Effect or Temperature on lPixaUon and Exchange Capacity in Potassium Saturated S:o1ls...... _.. 28 111

LIST o:r FIGURES Page Figlll"e 1. Per cent or Added PotassHun. Fixed Upon Moist storage ot Low Jlumic Latosol (No .• 50-91) at 266 ppm. K Application... 12

Figure 2. Per cent of Added Pota'.Saiwn l'ixed Upon Moist Storage ot I:fydl"O·l HWlio La:tosol (No. 49-37) att 266 ppm.. K Application••• 13 Figure ). Per cent of Added Potassium Fixed Upon Moist SU>rage o:r Dark Magnesium Cl~y (Bo. 50-92) at 266 ppm. X Application••• 14 Figure 4. Per cent of Added. Potassium Fixed Upon Moist storage at 416 ppm. K Application o-r KCl • • •· •· • •·...... -•• •·•••• ·• • • • • • • • • • 1S 1'1.gure 5• Per cent or Added Pe.tassiwn Fixed Upon Moist Storage at 1596 ppm. K Appl.1cat1on o-r KCl • .• • ...... , ••••.•. • .• • .. .• • • • • • •. • • • .• • • • 16

Fi~ure 6. Differential Thermal Curve ot Kaolin••• 31 Figure 7. Dif't"erential Thermal Curve of Bentonite. 32 Figure 8. Differential Thermal Curves of Low Humic Latosols. (A) No. 50-91; (:B) No. 50-222...... •... • • • • • • • • • • • • • • • • JJ

Figure 9. Ditterential Thermal Curves ot Iiwn1c La'tosol {No. 51-2). {A) Presenee of Organic Mat'te.r; (B) Removal ,e:r organic llatter with Hydrogen PerQocid.e••••••••••• 34 Ftgui-e 10. Dlt:rerential Thermal 01.1.t've of Hydrol Humic LQ.tosol. . {No. 5.1-l) •• •·• ••••••••••.,. 35 ngure 11:. D1f'tenmt1al Thermal Curve o~ BWldc .re~Qgino11a Latosol (No., S0-205) •••• •·•··•. )6 B'igui-e 12. Ditterential 'l'.b.ermal Curve or Gray Hydl."omorphic Soil (No. 50-220) ••••••••• 37 Figo.re 13. Ditrerent1al 'fhermal Curves ot Dark Magaesi am Clay. (A) No. 50-9.i; (BJ No. 50-221••••• ••• • .-. • •• .:. • •• •••.... J8 1

INTRODUCTION

Soi.l potassium exists in several forms, namely , water

soluble, exchangeable, non-exchangeable, and pri.ma ry mineral forms •

. Water-soluble potassium in soil. solut.ion 1s lim.ite·d to a range of one to ten J:8rts per million. '!'his amount is in-

adequate te IIBet the requirements of a crop.. However, there is a larger am.oant present in tb3 exchangeable farm as$ooiat ed witll tm colloids which is usually deter:miJle(i by the

extraction with w.mnoniwn acetate. This form is generally

considered to be readily absorbed by plant roots that make

conte.ct with it. The non-exchangeable potassiwn, on the other hand, is fixed and unavailable to plants. Ordinary

a.mnionium acetate extraction will not remove the potassium.

It my be extracted by HCl acid (4). Also the continuo us

extraction by plants will remove this non-exchang eable form

under normal soil condition (6) . Finally, the bulk of the soil . potass ium. is oontaine d in primary minerals, such as feldspars

and. biotite.

With tae clari.tica~ioa of tbe eati on exchange phenomenon

in soils, these terms were identified. But., it was known

for a long time that added potassium. bees.me fixed.

F1xat1 on of .POtass1um may be de.fined as the transforma

tion of soluble and exchangeable potassium to non-excha ngeable

:rorms. llartill, Overstreet and Hoaglam. (17} indicated that 8,ll.. t _le potassium fixed had f'unctioned in repl.acing Ca, Kg,, and.,N'fl, which appeared in tm water ext,-ract; thus su.ggest-- 1.ng an exehan.ge react1 on. Wood am DeTurk ( JJ) considered · this e;xobange reaction very important in their concept or potassium eq11il.ibrium in soils. Later Page and Baver {19) showed fixation of potassium w1 thin the lattice structare of montmor1llonitic clays. Another theory suggests the formation of muscovite, a secondary mineral, as desert bed by Attoe and 'l'ruog (J}.

This was also reparted by G.W. Volk {28) as supported by X-ray i;:etterns.

Conseqllently, the existence of potassium fixation bas peen well established by a number of investigators. Kost of their work seems to indicate greater fixation by high temperature treatment and altermte wetting and drying. In view of the fact that potassium ferti lize.r is used extensively in Hawaii am elsewhere in the world, the extent t o which applied potassium is fixed in tbe soil is or vital concern. Theretore, the primary objeet1ve ot this study was to determine the ability or certain Hawaiian soils to fix added potassium under va r ious conditions and to attempt to i dentify the predominant minerals involved. ( 3

DESCRIPrION OF S OILS t:BED

·aiei:at- diversity in the sotls of Hawaii has resulted from v~.ria tions in environmental· condit ions and topography .

The'·s'e $Oils have developed prima1·ily from basaltic l ava and volcanic ash (11) (12). Geologically, the age of lava and ash varies t'rom recent flow of , eruptive materials to the early formation of the Hawaiian Islands. Duri ng that pe~i od of tiIIe volcanoes in Hawaii have been very active .

'l'he annuai rainfall ranges from 10 to 15 inches in dry areas to ne,arly ~50 inches in excessively wet areas.

Drai nage is gene r·ally good but areas of poor drainage are evident, especially in lowla nd where nagnesium content is high.

Lat.erizati on is the most active and dominant soil f orming process in Hawaii. In this process e:xt-ensive leaching of silica and bases has t a ken pl.ace resulting in a l a.v silica-sesquioxide r atio -- usuall y less than two. Soil samples f'rom six ma j or Great Soil G.roups, represe·nting agrieulturally important areas, we1·e eolleeted fo-r this stud_y. Tbe se samples ~re taken, f'rom the first sartace toot. 'rhe six groaps of soils may be briefly desori bed as follow s:

*Low Humie Latosols from Poamoho,. Wa hiawa , are

* U.S.D.A. Soil survey Re port (in press) 4

characterized by their red color. They are u.sed extensive ly for growiJJg sugar cane and pineapples·. The exchange capacity ranges from 15 to 30 milliequivalents per 100 grams of sotl. Organic natter is lON ranging from 2 to 5 per cent.

The annual rainfall varies from 15 to 60 inches. The elays are primarily kaolinite.

Hum.ie Latosols from Tantalus, Oahu, and Laupahoehoe,

Hawaii, are developed under rainfall ranging t'rom 40 to as mueh as 150 inches annually. In these soils the kaolinite minerals are d.ecomposing to a mare stable alumlnum oxide

(22). Simultaneously, witb. lack of aera tion, the iron oxides are being reduced and leached from the soils. The pH ranges, from 4.5 to 6.o. The cation exchange capaeity averages 45 :mi.lliequivalents _per 100 grams of soil.

Organic nil tter rang es from 10 to 15 per cent.

Hydrol Iiwnic Latosols from Pepeekeo ., Hawaii, a:r~ developed under excessively wet areas. The annual rainfall averages 120 to JOO inohes, am in the natural condition they are continually wet. Organic matter is high ranging from 15 to 35 per cent. Due 1io the tremendous loss of water upon drying, their volume weights are extremely low..

But they do not revert to their orig inal form upon hydra tion. The clays a re largely oxides. Hum.ic Ferruginow Latosols f r om Li b. ue, Ka ua i, appear r a ther grayish to purple. VolUJE weights of these soils in contrast to the Hydrol Hwnic Latosols, are extremely 5

hig h resulting from the accumulation of titanium. and iron o~i,d~s {23} (25). Leaching 1s intensive whiC"h acooun-ts tor

t he low base saturation. The annual rainfall r anges from 35 to 150 i nches. These soils probably represent the e nd produet of soil format ion for the latosols under a wet and dry climate (22). Grax Hydromorphie Soils f rom Ewa, Oahu, are character-

ized by l evel topogr aphy, poor drainage, and the accumulation or magnesium.. They are heavy and plastic and are easily dispersed. Large number of surf'ace cracks appears upon drying. 1rley are neutral to al.kalim in react1on. Dark. Ma.gne slum Clays from Ewa , Oahu, are characte.rized

by their dark color am sticky, highly plastic consistency. They contain high accumulation of blses ot calcium and

particularly mgne siwn.

Exchange caISeit y is rather high. The magnesium saturation is usually more than JO per cent. They are not

truly developed solonetz but are in the process of desali

nization. Montmorillonite is probably the predominant mineral. Active dolomitization is also present in small

areas (24).

Som properties of the soils used are shown in

.-...... (. table l. Table l, SOME PROPERTIES OF SOILS lJSED

; Exohaygeable Cations Soil S~il Soil Exo.b.ange Oraanio Number Group Family Location pH Potassium Oalo1um Magnesium Oe.pao1,y latter I ! . t I m.e./100 m.e./100 m.e./lOO m,.e./100 .Per cent

49•J5 Humio Oolmla Laui:ahoehoe·, 4,J .20 14.00 Latosol A-j Hawaii

49-37 Hyd;rol .Akaka Pepeekeo, .19 .39 18.00 .HI.Uni o X8 Hawaii Latosol

S0-91 Law Hum1o WahJ.a wa Poamoho • ll,S 2,84 'Lato sol x; Oahu 50•92 Park L-.lualei Ewa, Oahu 17.39 17.95 Ju}O Magnea1 wn. M Olay S0-205 llumia Haiku. Li.hue• Kauai 4.7 .66 17.8 7.30 ~ Ferrug1.. T'J nous Latosol 50... 220 Gray Hono\ll.1ul1 Ewa, Oahu 7 .4 ,.34 19.44 J.3.J 1.69 Hydro- Hl morphia Soll 50-221 Dark ,Lualuale 1 Ewa, Oahu 7.J 1, 09 Magnes1 wn · II Olay E~ohaneeable .oatio.ns Coont.} '' \~:,1'4" ;.• ,, ,~·Mn"' Soil sor:f· Soil Numbe:r Grou J'amil Location PB Potassium Oalc1um. Magne,1um m.e • 00 m.•e. 50-222 Low Hwa1o Wah1'.wa, Foam.oho, 5.3 •8) J.8J 1,JS ll.8 2.22 J;.,e.tosol ~, Oahu 51•1 F(ydrol at.lo. Pepeekeo, 4.5 .JS .37 1.20 47,2 16.94 Humio X:6 Hawaii Lat·osol 51-2 "Humio XaJ)oho 'l'-a.ntalWf, ;.o .•48 3.06 ~.99 ~0.4 15.68 l:,e.toeol A9 Oahu 8

METHODS OF ANALYSIS

-·:::··~ :S:eils were leached ot exchangeable cations, with B ~~iD.m acetate adjusted to pH 7.0. Peech's (20)

centrifuge method was employed initia-lly in determining potass!:um in the extracts. Bow~v,er', this method was not adapted for large quantities of potassium. The cobalti ni·t:tite method ot Volk a.ad 'fruog (.30) was more s uited for the analysis. Flame photo:aete.r was also used rather

briefly. Calcium in the extract was determined by -, precipitation as the oxalate~ follOiled by t-itration with

potassium permanganate. Magnesium was deter.mined by

precipitation as the ammonium phosphate, followed by titration with a standard acid solution.

Cation exchange capilcity was determined by leaching

the soil with N ammonium acetate, followed by distillation

and titra tion of the adsorbed ammonia. Organic mtter was

determined by a modification of the Walkley - Black method

(31). Soil pH was determined by the use 01' Beckman pB meter. ( 9

PO'l'ASSIUM FIXATION UPON MOIST STORAGE

Results of both positive and negative fixation upon moi.si storage have been reported by inves,tigators. Attoe and Truog (J) found no tixation after 7! months of moist storage. Stan.ford (27) reported little or no .fixation of potassium by montmorillonite. On the other hand, Raney and Hoover (21), working with montmorillonite, ' showed as much as 2J per cent tixation. Attoe , (2) in his later work. found tha t fixation ranged from O to 17 per cent in the ease of the .fertilized soils.

'l'hree important f'actors ha. ve been reported whioh influence fixation upon moist storage , namely, rnte of application, ti1re of st0rage~ am the eff',ect of anions.

Bray and DeTurk (8) showed increased fixation of potassium with greater add.ition of its soluble salts.. This may be looked upon as a mass action effect whereby a state of equilibrium is attained. Wood and DeTurk ( 33) also noted greater fixation with heavier application, plrticularly with soils of high exchange capacity..

.Although fixation upon moist storage is general.ly conside:red slow and gradual, Martin, et al. (17) have shown rapid fixation which was established in 48 hours. Wood am DeTurk (33) determined that the efl"ect of t~ on fixation varies with different soils and differenees in geolcgice.l ag,. 10

'file anion effect has been considered important gy ae,'ve~a.l iarestigators. lot fe a11d Xolodny (l.J) showed b,i.gher potassium f'ixation with increase in phosphate ions.

Rane_y ,~ Hoover (21} noted tba. t at,. 216 .PJ>m. K the KCl ' ~- s?i9.;d a higher percentage :fixation, but at 2,160 ppm. K .~_: '',i the ~Po4 nxed a greater percentage. In order to determine whether llawaiian soils will fix added potassium, the fol.lo.ving experiment was carried out•.

A series of 25 gram samples of soil was kept moist in stop.pared .Erlenmeyer flasks contai,ning 20 ml. of potassium . '",,

solution or three different concentrations, based on the weight of soil.. '?be applications were 266 ppm. K, 416 ppm. K, and 1596 ppm. K. The samples were stored for one hour to eigl'Jt weeks and periodieal1y the exchangeable potassium was extracted. In addition to the study of time

interval, tl:e lnfluence of anions and the ef:t"ect ~ air drying the fl eld soil ba ve been considered. However, differences were not observed as indi eated in figures 1, 2 and J. l'ixation is determined by the difference in the amonat ad-d.ed a.nd that recoverable after storage. Low Humie La.tosol (No. 50-91} ot figure 1 indioatea no f'ixatlon. Rather than fixation, the first few days ot storage showed som:3 release of non-exchangeable potassium. Hydrol Humic Latosol (No. 49-37) of figure 2 shows no fixation al.so. However, Ayres and Ragibara (5) f'ound 16 to ll

21 per cent fixation when potassium was applied in the tar~ or, K)P04" With KCl, K2S04,._ KH2P04 KP0.3, or with m.i.xtures ot KCl and eitmr of the su.perphosphate or a.m.m.oph0$ no fiocation was evident.

Dart Jla.gnesium Clay (No. 50-92) of figure J, unlike the ot..her two types of soils, indicates definite fixation. With longer storage, fixation gradt1i lly increased, and at four to six weeks about 10 to 16 per oen.t of the added potassium was fixed.

Figure 4 indieat.es results obtained troi& t-he a_ppliea tion ot 416 ppm. K. 'f.be se soils were collected at a later date to supplement the other samples. Gray H.ydro- morphie soil (Jf.o. 50-220) was a.lso included. At this concentration and in following experiimnts addition of phosphate ions and the moist field soils was purposely omitted because previous study showed no effect. An exception is tle Hydrol Humic Latosol. Since this soil is continually moist in the natural condition, it was never allowed to dry in storage. Evidently, at 416 ppm. K application fixation was absent. Since fixation was not apparent tar most or t.he soils at 1ower rates of application, a concent-rat1on of 1596 ppm. K was emplo7ed. It is generall y believed that higher application brings about great.er fixation (15) but this was not the case, as shown in figure 5.. Even Dark

Magnesium Clay (Ho. 50-92) failed to fix·Hiny pot.ass1um. Humic Ferruginous Latosol (No. 50-205) was inelttded in this stu.dy also. 12 ~ H E,'4 · 10 e 8 ~ 6 _.. (A) E 4 - -- (B) 2 (C) 0

4 ! 6 i 8 i lz1 10 p.. 11 t I I I I I I I 4 8 12 16 20 24 28 32 36 42 TIME - I N DAYS

~ ~ , • 1. us1 tixe ,t 18 t ta\Qa 1, - • ( • ,1 • (.A) 11, { I ' 1., 11• 111 (0) EOl '. a 1 ( I' 1 t' • 1. 12

~ 10 H 8 ~ 8 H 11<4 6 ~ 0 4 re ~ 2 ... (A) 0 •..• . - . -:-. -. ....- . . ·('B)· ...... , •.. . .. - - ..... 2 ' 'e- - --~~~~~~~..:.(~) 4 ~ (~) 3 6 ~ 8 8 ~ p::0 10 rf 12

4 8 12 16 20 24 28 )2 )6 42 TIM E - IN DAT S

Fig. a. Per oent ot ·a.dde4 po. asium ltJ.xe4 upon moist storage ot Hydrol HUJD.10 La 0,01 (No. 49-)7) .t 266 pp. K _ppl1oat1on (AJ ~Po4 added to moist ti• d aoil; (B) KH2Po4 added to air•dl7 aollJ (0) KOl added to air-dry soil.t (D) KO}, added ,o moat tlel4 oil. 18 ,,. (A)

16 / / / 14 / / I ~12 _.,,,, E-1 ~10 --- ~ ·-- ~ 8 ,~~- •---r.c----.. i 6 re /-;..- -- / ----;.. 4 I I 2 / / ' / 0 ...... ,1'. ·;/ ...... ~

4 8 12 20 24 28 32 36 42 T I M E - I N DAYS

Jig.). Pero , a • aaa1 tix• p t ( • 5 92) at 2 6 · 11 ti •• (A) 11 tiel • 11, ( ) l & 8 ail'- 1 11, ( ~ 12

• 2 0 ...... /'=~~--=--- -·-'-' :..· .:.·.::.; ~i: :..-- ., ...... ____ . ! • -- • ,,. '· -. . ~ :>--<--.. -- ·~-. --· . •,,.,,. ·,.-~-...... ----• · . / . / . ·- ·- - . / ...... •- --- ...... • -·. I • ...... , (D) ...... / - , '• ...... / ', / ' ...... / 12

7 14 21 28 35 42 T I M E - I N DAYS

Pl$• 4• . Per ent Qt add. d potassiu tixed upon moist storase at 416 p.p.m. K application ot KOl, . {A) Dark llogne iwn Ola, (No. S0•22l.); (B) Gray Hyclromorphio Soll (No. 50-220); (O) drol H ; c Latoaol (No. Sl•l); (D) Low Bumi Latoaol (No. S0-222). Eaol) po1nt irepresenta a t,:rage ot dupl1c ate e ple • 12

1,...... ,...A_ (A)

' :...:.'- ...... ~ .~:. -:-··_'---_. ::::i,· ... • ~-----_-_··_-_·_·: 2 ' "'· - ...... (BJ ' ...... -...... 0 ...... ':' '"'(.: ~•. ~ ~...... : ...... '' ••(C) ! '•------• ...... ------._. --. (D).

7 14 21 TIME - I N DAYS 11g. ,. Per oe ad ed pot a iua tixe up is at ra t 15 p.p. • I: appU ,1 ot 1. (A) um1 'lerrugi.no Lat ol ( . ; 20.5) I ( ) LW um1 Lat sol ( , 50-91); ( rol La ( • 49-J7); ( ) ea1 la, ( .' 2). oi Npre e \ av 11 " ••• ( 17

POTASSIUM FIXATION UPOlJ AIR-DRYIW

Foi.lowing tm study on moist storage, the effect o:f ai~..... dryl1g the soils with added potassium' was considered.

Attoe (2) noted considerable evidence of fixation when a potasSiWll fertilized soil was air dried. Wo·od and DeTurk (JJ) also foulKl increased fixation upon air-drying tor one week. With heavier applications, they were able to show greater f'ixatton, particularly with soils of high exchange eap!lcity. To study th:! effect of air-drying,, 25 gram portions of soil were placed in Petri-dishes. Potassium solution of different concentrations was added to the soils, and tba mixture was allowed to dry at room temperature for a week. Then the exchangeable potassium was extracted. For each concentration duplicate samples were analyzed. I At lower concentrations potassium was not fixed as shown

in table 2. At 1596 ppm. K application potassium was fixed by Dark Magnesium C.lay and Hydrol Humio Lat.osol.

Low Humic Latosol, on the other hand, showed some release of non-exchangeab.l.e potassium. In another approach to this subject a study was n:e.de of drying a fertilized soil to the wilting point. Low

Humic Latosol (No. 50-225) was used. for this experiment.

In thi.s study, fifteen Mitsche:clich pots were used as follo.-s: 6 pots were treated with KCl solution, '6 pots were treated with KCl crystals, 2 pots were used to grc:Ni ( l.8 sunflower to determine the wilting point, and l pot was used as a check. KCl equivalent to 125-0 pounds ot _x2o per acre was added to each pot. This application is somewhat comparable an amount of 250 pounds K 0 as to 2 per aere generally practiced on plantations where kcl is narrowly concentrated. At five different moisture l evels, ranging from 17 to

28 per cent, the soil was analyzed for exchangeable potassium.

Triplicate samples were taken for potassium analysis and duplicate samples for moisture determination. The wilt.ing point of this soil, as determined by the use of sunflower, was 22 per cent,.

In the first series of six pots where KCl solution was used fixation was indicated at the Jligher .moistare level.

However, below 23 per cent moisture no fixation was evidenced as shown in table J. In anot.l::e r series of six pots crystals of KCl were used to simulate actual plantation praotiee of addi~ potassium. fertilizer, but fixation was not appar ent. l.9

'fable 2. EFFECT OF AIR-DRYIW ON FllA'fIOlf OJ' Pa?ASSIUII .. Exchangeable Potassium ~oil Soil Potassium · Alter · 1NU'lill:> er Group Added Initially Dryi~ - Differenc~

• I~ . - : •• ;;:J_, ppm. mgm./25g :mgm.,, -~_5.g mgm.. 5t>-9l; L.ow Bum.le 266 10.4 10.2 . 2 - ,_ - · -::{ Latcisol 50-222 ff 500 17.7 17.8 .1. .

~~9J. 1596 4).8 45.3 1..5 50..92 Dark Mag 266 lJ.6 lJ.5 .1 nesium Olay j,0.2:21 II soo 20.J 19.s .4 S.0.-92 ff 159' 47.0 J;.4..8 2.,z 49-37 Hydrol Bum1c 266 8.2 s.1 .1 Latosol ,51-1 " 500 12.6 12...5 .l 49-37 It 1596 4-1.5 J9.J 2.2 50-22-0 Gray Hydro 500 l.) .5 13.2 .3 morphio ~0-205 Humie 500 11.8 ll.O .8 J'erruginous Latosol

;1-2 Hwaio 500 14.22 Latosol

Each r1gure represent,s average ot duplicate samples. 20

'fable J. EFFEOT OF DBYIM 'l'O THE WILTING POINT ON FIXATION OF POTASSIUM IN LOI ,BIDHC l.ATOSQL. (tll) .se.n. NO. .5-~Z25

Exchangeable Potass.iwn JUtscherlich Potassium Upon Pot Numb.er Moisture Form . Initially Dryi~"'· Di:fferepce · · · · Per cent _mgm. /25g

397 28.0 Solution 23.5 22.3 1.2 398 24.8 " tt 21.8 L.7 399 23.2 " " 2).6 .. l 401 21.5 " " 23.3 .2 4·80· 1.,.8 " .. 22•.6 .9 403 27.9 Crystals " 22.7 .s ~04 26.l " " 23.6 .• l 40; 24.4 It " 23.5 .o 407 22.4 • " 23 .. 2 .J 4.06 17.5 ft ft. 23.3 .2

Each t'igure represents average of triplicate samples.

Wilt.Ing. point ;,. 22 pel' cen..-t. moisture l.2SO los. K 0/acre appl.ie at1on 2 21

POTASSIUM :FIXATION UPON OVEN-DRYIW BUMIC LATOSOL

oven-drying offers another phase of this study which 0 i& or academic int-erest. Heat treatment up to 200 C ten.dEs to facilitate f1xat-ion (8)(9) beca1:1:se equilibrium is approached more rapidly. In treating soil samples over 2000 C, Jof:fe and Kolodny (14) showed decrease in .fixation 0 for montmoril.lonite clay. At 550 C complete destruc tion of fi.xing capacity was noted.

Hum.le Latosol (Ho. 49-35) was used in this study. '!'his soil was in.1tially t-reated with various forms and ~ ! '. ·.· eombina tions of potassium salts p:i.rticu.larly the phosphates;

subsequently, the soil was leached with nearly 100 inches of

water. The amount of exchangeable potassium present after

leaching 1s shown in the third column of table 4. 'rhis

amount was co mpared with tte t of the same soil oven-dried 0 at 105 C. As the results sh

from 20 to 40 per cent of the exchangeable potassium. 22

b:changeable Potassium ·so11 :; Aft.er* ·Depth freatment In1t!ally prl1.DfS Dlt"ference K Fixed mgpi.,./25g mgr.ii../25g mgm. Per cent

0-12 Check 1.2 1.3 surtace " KCl+Ammophoa 3.7 2 .. 4 1 • .3 35.94 KB Po 5.8 4.,2 l.6 28.•4$ " 2 4 ~P0 -tKCl 6.5 4.6 1.. 9 29,.92 ~~.....,_...,:,·.,",. ,, 4 tt ICPO 5.9 4.0 1.9 .32.65 J 12-24 Cheek 1.7 1 .. 6 .. l Subsoil

.. KCl-tAmmophos 4.4 2.. 7 1.7 39.93

ft KH PO 6.4 4.. 7 1.7 2·7.75 2 4 KB PO -tKCl 7.7 4.8 2.9 37.52 " 2 I+ " KPOJ 9.3 6.4 2.9 30S7

0 * oven-dried at 105 o 2.3

POTASSimi FIXATION UPON ALTERNA TE VlETTIID AND D.RYilD

Many investigators bave reported greater fixation when so.,ils were subjected to alternate wetting and drying proce,ss.

Martin, Overstreet and Hoagland (17) show~d that in this process potassium fixation was not dependent on the presence of clay minerals of the expanding la. ttie e type. This is not in harmony with Page and Baver's (19) theory, which is based on the .formation of a stable structure upon dehydxation of a potassium. saturated system. This stable structure is t'ormed onl.y in the expanding and contracting lat'tice mineral such as montmorillonite. o.w. Volk (28) also found tremendous fixation by this type or mineral after al.ternate wetting and . 0 dl'ying t wenty tim s at 70 C. Using the same technique, ?i.J.. Volk (29), working with 100 dif'ferent soils, was able to s how fixation ranging from O to 114 per cent of the added potas.slum.

In view of the high f'ixati on data obtained by other il!'lestigators, an attempt was :ma de to determine the effect on Hawaiian so.il.s as.1.ag this .method •. However, instead of' 0 drying at 70 C as Volk did, it seemed more practical to dry tb.e soils at room temperature. Twenty-five gram portions of soil were placed in Petri-dis.bes and saturated with 20 ml. of KCJ. solutions or different concentrations. The soils we.re allORed t.o d.ry at !"00111 temperature for a bo n t a week; t .hen they were rehydrated with water. T'his pro.ees s was repeated three times. Far eac.h coneent..ration dupl.ioate 24

sample.a were analyzed•.

.Lav Hum.to Latosol (No .• :50-91 e:ad No. 50-222.) showed 11ttle fixation, 9 per cent being the highest amount fixed at 500 ppm. K application.

Derk Magnesium Clay (No. 50-92 and No. 50-221) showed s. much hi g her fixation. At 266 ppm. K application tbe soil fixed an average of 11 per cent potassium a.nd at 500 ppm. K, f'lxation was as mueh as 19 per cent. However, at 1596 ppm.

K, an average of only J i:er cent was fixed.

· HydTol Hwnic Latosol {No. 49-37 and No. 51-1) and Bum:ic

Latosol (No. 51-2) did not fix potassium at all. Bumlc Ferruginous Latosol (No. 50-205) fixed an average of 8 per cent at 500 ppm. K application. Gray Hydromorphie (No. 50-

220) showed an average of 7 per cent fixation.

Dark Magne slum Clay again showed the greatest amount of fixation. It is very probable that drying the soils at higher temperatt1re V'IOUld bring about further f1xation. .,

50-'1 166 l.o.l ..) .CJ

ft .- . aa---· ,. 19.Jt 1a•. 1.1. t .fo J £..w .. 43.1 u. l.Z • , Ji,-92 ' ·266"' 1).1 J.J.o • u.as s ·· aJ1 • JOO, .o 19.,f a.a ll.64, J 12 1' 1J'6 i.1.1. 46.,l 1.0 a.60 4 J? 266 IJ. .., .a ... ,1-1 "' ,. 14,., u..1 .2 - 49-)1 •• 1,,. 41.4 .o - OS 166 .... 1 .o .. ' "' $00 t--- U.l. •-' ,.1 • ,JM ·t.-0,., /t.O•...... 0-80 .lJ.7 i..t 6;.,, '1•1 ,. 1J.4, u.1 -.J, .... 26

THE EFFECT OF PGrASSIUM SATURATION Off FIXATION AND, ffl -llCHA?CE CAPACITY ,

In tl:ae tlxation process tm exchangeable potassium is ge.::tu9.ral.ly converted into non-exchangeable form. Accordingly, soils saturated with potass1wn would seem to favor fixation.

To test this point , an experinent was. carried out by saturat ing the soi.ls w1 th N potassium acetate and heating t .he so.ils . 0 0 tuto:·'l~ hours at temperatures ranging f'rom 25 C to 100 C to facilitate the fixation process.

w,,ar and White (J2) showed s1g·n1r1cant de-creases 1n exchange capacity w1 th an increase in fixation when potassium 0 .saturated soils were dried at 105 C far 12 hours. This was JBrticularly evident in soils of 2:1 mineral structure like the bentonite. They claimed that illite, which is also of 2 :l mineral structure, did not fix as much potassium because it already contained large amount of potassium in fixed position.a. Levine and Joffe (16) also noted the same relationship between fixation and the exchange complex, but not in equivalent amount. Bars.had (7) was able to sha.v that the reduction in tbs exchange caJBeity was dt1e to vermiculite or biotite minerals in soil.s,, Potassiwn in these minerals caused the crystal lattice layers to contract, thereby entrapping tl:¥9 potassium i n the mineral structure. Ammonium, eesium am rubidium react in a manner very similar to that of potassium.. The f'ixed cations are exchangeable only by such ions as sodium, magnesium, calcium, and ba.rium, ( 27

w.nich when adsorbed, caused the layers of the crystal ,'. ~h'ti.qas to expand. ···, ·'. -·~ ·-,.'"'-~)" In pursuing this study three soils wer·e used, namely,

G~ijt,' Hydromorphic (No. 50-220 ), Datk Magnesium Clay {No. 50- :. - ·, ~ -: !·;:; 2-41), and Low Humic Lat.osal {No. 50-222}. As shown in table 6, Gray Hydromorphic soil shewed little fixation with

i ncrease i.11 temperature and a slight reduction in exchange .- ~ - capacity.. Dark Magnesium Clay showed greater fixation

with increase in temperature and a considerable drop in exchange oapaoity. Low H_um.io Latqso1·, on the other hand, behaved somewhat differently. At 50°c fixation was at ita great.est am decreased as the temperature was increased. T'able 6. EFROT OF TEMPERATUR E ON FIXATION AND EXOHAIDE OAPACI'l'Y IR POTASSIUM SATURATED SOILS

0 25 0 0 J;,8 0 42,4 0 14,7 ·o 50 0 2 ..•;7 JJ ,5 8.54 ;9.4 9.79 14.5 8 7.5 0 ).S6 33 .• 4 9,39 39,6 s.99 14,4 1.00°0· .5 ,,8.5 33,.0 1).79 39,4 2,65 14.7

*Excl:l,a.nge oapao1~Y ot potassium sa~urated soile. ( 29

DIFFERENTIAL THERMAL ANALYSIS OF SOILS USE.D

S:inee DBny soils in Hawaii are mde up of over 50 pel"

C~!).t olay fractl,ons, tm identification of clay minerals is

e~:reDEly important. To a large extent these minerals

determine the physical. and chemical properties of soils.

Differential thermal analys1~ (26) provides one of tbe .. methods of identifying these mimrals. This analysis was

included in order to substantiate tm experimental data.

Bri-e.flJT, this .11Ethod is based upon th.e fact that the ' .,..., - application of heat to a mineral causes certain physical and ehemioal ehange.s th.at a.re reflected in endothermic

and exothermic reactions. By comparing the change in temperature or a mineral heated at definit.e rate with t hat

of a therm.ally inert substance (Al2o3 ) heated under the same conditions, a curve or p:i ttern is obtained which ~~ eharacter1st1c of the pir~lcular mineral under examination.

ho standard reference sampl~s~ *, kaolin and · bentonite, were run for thermal curves which represent typical 1:1 and

2:1 lattice minerals respeetively as sh.own in figures 6 and ... ;/·{'i:(,"

,,· ,.•-:,. ·-·- ,,·>·1· "!':.!. ~-:·\·~-:-1 \·.; met-er deflections or end·ot.b8rm1c and exothermic reactions

of t l::e clays • Kaolinite ms two critical p:,aks, a sharp endothermic 0 0 peak at about 600 -C and a sharp exothermic peak at 950 c.

Samples obtained through the courtesy of Dr. _G.D. Sherman, * u.H. Expt. Sta. ** Part of the analysis was done by T.A. Jones , ( J O

T.bes~ peaks are very distinct as shown in; figures BA and SB

or the Low Humio Latosols, 'i'ilich m-es contain nearly 80 l)er cent kaolinite (18). These points are also present in

other types of soils but not as pronouneed. Matsusaka (18)

was able to identify kaolinite distinctly with quantitative

data,. which seem to agree fairly well with his dehydration

curves. Re follD.d Kaolinite content rather low in young soils like Reddish-Brown and increased amounts in Humie Ferruginous Latosols and Hydrol Hum.le Latosols. Low Humie

.. . : .. Latosols contained the highest amount •

Montmorillonites are not as easily identified in

Hawaiian soils. The reference sample, bentonite, shows the 0 0 0 endotmrmic peaks at a:t>out 100 C, 700 C, and 900 C. Dark llagnesium Clays of f igures lJA and lJB show all three points

on the curve indicating the presence of Montmorillonitic

Clay and little kaolinite. Gray Hydromorphic soil or

figure ll shows greater amount of kaolinite and a

questio.mble presence of 2:1 crystal lattice mineral.

Bauxite, goethite and limonite show large endothermic 0 peaks at about 350 C on the ditt'erential t hermal curve.a.

•.:• .•. ;-..- The1Je are easily idmtified. in Humic I.a~osol, Hydrol Humic

.., . ~ •, Latosol, and Humic Ferruginous Latosol of figures 913, 10 and ll. Figure 9A shows the ma sking effect of organic UBtter on clay minerals as co mpared to figure 9B the same soil with organic m tter removed by hydrogen peroxide treatment. 31

25 -

0) C) 5

•H A

~ IIQ 0 ------.. ------..CXI .4

~ 5 u Cl)

flg. 6. D11'terent1al t.ber:aal cum or kao:U.n...... 25 ·

Cl)

C, 5 z H Q <

lzl O ------______. i::i::

100 200 )00 500 600 700 800 900 1000 T E I\IP E RATURE - o C

Pig. 7• Ditt \onite. )J

IQ ...• A 0 ...~ Al ... t4 0 ------~ u IQ

100 200 )00 400 600 700 fOO 900 1000 T:SKP:SIATUR:S - 0 c

11.g. • tial {A) • 50-91: ) • S 222• 34

Cl) c., z H

(Al ------

~o < ------0 0)

100 200 JOO 400 500 600 700 800 900 1000 TEMPERATURE - 0 0 9,. D1tter.at1al tr.m:al 0 ( o. ~-2J. (A) pr -\te~u - . (BJ r 0 . or ·gan1o I1B.tter with Qydrog-en peroxicl 3S

Cl)

0 5

•M A ,.; 1111 0 ~ ------

- 15

100 200 300 400 jO() 600 700 800 900 1000 'l' E IIPBBA'l'URE - Oc

Sl,-1). 25

ti) C, 5 z H A < lxl 0 0::

lxl o-4 < 5 0 ti)

100 200 JOO 400 500 600 700 800 900 1000 T E M P E R A T U R E - o C

Ditt ntL l 37

Cl)

z H A < r>J Q ------0::

100 200 JOO 400 500 600 700 800 900 1000 T E M P E R A T U R E ~ o C

J'ig 12. Ditterential thermal curv ot Gray Bydr orphtc' aoU (Bo .. 50-220). Cl) 0 z 1-1 A 0

~ 0 H < 0 Cl)

100 200 300 400 500 600 700 800 900 1000 TEMPER AT .URE - o C

• JJ. Ditt • • 5 • "

-,.o.u, 'to t11 14"uela u tM .· 04a110 aoila of 11»

UJS..1:~«t s .ttt•• ·A ••11 ~ la~nauu ia ven aott•• e .· ffaoll.nt\to Ul/1 ontio m.aMla Pl1'•4or.a1na-•-• 1 i.eo • '·,.•=-•l,s 4<> not. t.1• •ll. e.ot b.l• · · uau ·of pa\tlh1 • bratl; boftl!' U) .ud tAhea v-e aotf:a no ti-za ·- 1 . with a -· ·l t.1:e o0llo14a Moa•• ,,.. ,nC•la.&1 ··· atae&l \1p; oouial.a « •...... ,..s. -Wt••·· A4 ..· :YU tJ.j.J nJ.a : . lie 1 · o •tu at : ..ani · to Ute ~ 1&•tl t1:i• llla-..1 &a «••r1bi.cg 11.a,1-. Aa -~ J. VolJtta (29) : .· au 'MG-Ute · ft aollo tr.ca .lmira11 ·....- -. H•ff ~ - OM --.a

. • al'-'- ft. . 1QS d4 IP'i'UII • llft,elezit• Bo.

f JG .....

HaU. • •t Wa •tu.tr •Q·.•W;li,. k , • .tuadl:tl•_ d i.a•oaolil 1A tiPF.• 9i an4 10 c&naa t.4 of o:&1 •• aa4 •• , 11• .ldaenLJ.. lhPalc hffGCb · iAt:o l of t~• 11 eon ia,., tr , .11, f4. t,.1- ont •• ·IHI' - ro~~»Al o1.l.,' es 1D41u." ·· 1n ZA.lsa• 11, :ta1J11ut aol.1 • ·• at »· -.,11 ail l. "'-it• a&RJ.. nax _· ,t · eia ,01a1 . 111 t1 . ,fta .l)A a.m J.Ji 06tl !$'kt of

kaol.Wte· an:l 2il 1a,11oe . .r. ral

IfPh be mol131'h -o.on-t,en, •s ·h 1wff 111 ~ ·. · · aia.

OU1s •J.;aa 1.a LR Baio JA\os~l w Gray s,~; pUo a:011. WM pnhaO ot #tl l 'ltcf.o• . -1• S.n GnJ ~a,..

· p ,0 lluk ;·. JttNti.• «1-,. 1a •••t;antlatfld h7 ti» lfl'01$71.S.' .• GOID la tet>le 1. Thea. aoue JX'HUKUMi U&b ,:;u ·.• cia.aoilie•• hisA '4M aet,m, -tl~• ~ - bid' • .ti Mi • . tbro: aou-$ ·thu stu1, Dtil"'t bSa&ai · · aa t,M ont, aoil th•I o.oa&l•t JtUJ hffn4 tixat! -11.., Upen . a\ • · ~aa•, ad Jlll'hr ( ) } Q:J!e a . · -~o .: ow t1 \toa wt a.441tio.a or sol.a: e pot.au1a n1,,, 1 aoo wJ.tih lhe:11' e q1tUi1»:> i.t11a ooiu,.,, u . . :-fo.Hnl pe te•• :WT1 . · • ' h la qu1.l.1bl-1 · I" . · a nQ\ v••n•4 1.n ta1a ov .· I ••di'. ·· .a'li.va . • · at • 111&1t.e4. ta ~ -...a1 .O lA; ai ·66. J,a.. Jt 11. A ..i aa4 !aw . (l) tOUJII • · uillhri . or ,potaee1 a t.... bniJ.an aolla. ~1'•1 net.ft J*:r ou• tinUoa r._ ,, 4 •,oa ao.ut. -•t~• or-awo •• H :rol Jlml1o Laffodl.a. . 1M• Z,Pt4 fc;JU •tr~r tt~s1 · . 41a voa hlVUlf•S., t•• n• M.ona aT• soawat tiff•Nnt... Aecoftiag · · , ._, 4 (2'7) ,ii o-QP1J AN an _Ja le ~kn e1te At o.n tin'tloa. The ns1.tlS · .. tJ'tt , \ .tl"'~•ll 1~'11 1a ee~U- .PQS1tl · : wi'aill \he

min nl •~Jt•tUs tJt ,111 . 014 0011- fU'4l Aiuat;rall:D4 •1 t baMs, al tbl• 1io•u. 1n aemo ..... ,., ta:a1Uta"1i 'tllJ . _ »:>K••1a i · . . 1.llto latUoe alti , W:M-N

.-~ ,-; .. . tl-··. ta ttua• plaee• A1.-. 71Jrs la n o'thttJ' • ot. .~ t lli.e twt.· wbio ,pre - 1.ls wader .&aturAl on41t1on. 1'111 higtier aJplloa:tloa

4 t1n1wly ta 1o- gnat iM.tUtieit _· no.-tr.uon •~ t,ho J!/Jtae•1• u.J.'le. T~• ea ·bl•• a •••• ot Jll"&Plllttd.'1' 1D ni,·t ·• _- :u »••••1 1.o • .a4 ,_, ola•·· .. 0-11.-., i-eaul't•

1 - 1n '-h• O'QJ!lYU'fif) ·Of S lit le Nt4 e~b~J.fi ~eaet•

Q ua. sok cgubl.e t .: .: .. ~Ila, et al.. (17) ~·••

t.het tt.u: oa • 117.lQe ~ •· et, .rliiu lelUaot •. . ~ ~ :"" . .·.~---: ....-:..· . wa-t . •• lon 1a t-a• , .. ··~ ,•;, laena•• _.•· alt •---• .\1qu1 ,....

1n ~An l"GJA1•4 up•r1 nt 1a wM iae tkmlo JAtos:01

(59. 4,f•Jj) , bi,e At lOj°C, t1D\1QJ!

1' 1 y N Otf.tlaed by 1th · bf 1e. ~• se tn IU)lB..$GlWl 42

of drying at a hi.g.ber temperature, or by the combination or

\~ - ,. ,. these. taetors. Jorte and Kolodny (l.J) showed higher ,

potass ium fi:xati on with increase in phosp.ba te ions • Any

condition Which facilitates tm release of phosp.ba te aids tile recombination or this pho.spmte with other cations, thus favoring t.w fixation of pot.assium. .According to Stanford (27) the precipitation of iron anl aluminum phosphates caused an increase in potassium fixation. This Humie

Latosol my C(?ntain as much as 50 per cent * of its minerals

as the iron and aluminum o:xldes-, '.' whioh could react chemically

with the pl:lospha tes in the fixation process. With less than

10 per cent montmorillonite in this soil, it hardly seems possible that this amount will influence .fixation. As a

n:atter of fact, Stanford and others found less fixa~ion with add ition of phosphate ions to montmorillonite.

Generally speakirg , therefore, moist storage and air

drying produce very little fixation.

Alternate :wetting and drying presents anotoor· approach to this problem. Several vror kers have shown tremendous

··;:·· .l I •••• fixation. In this experinent, as mneh as. 19 per cent :fixa-

•, ~ .

. ~~. tion was noted for tlae Dark Ma~sium Clay while the other soils showed some indications of it. Evidently this alternate

wetting and drying process is more suited for the expanding

and contracting mineral in facilitating the entrance of

potassium ions. Page and Baver (19), as already mentioned,

associated the ionic size of potassium with the expanding * Abstract of American Journal Society Agronomy 1952 Annual .Meeting "Chemioal Allocation an'

lalt. ,o ainaral. • fill 1a41oai-1~ tie J• b.l FD4ft t:~ blla• . ttM~fl •z ~ ·*' a•S• C · 1• u $:o· •.h pNs•nee or • aJpcud.aW. GR.Olm,\t ot tJilt •• · a41n,g a:l. latt1oe . ·. 1'tlllf. · .tae itura JGZte (16) -.,.. a,bl_. to uo· e rela\lorumi p

~o,1oa ·n4 -~ 110••1· . 1 ·. a tuat. l ••• Uroct-- 11 t \ ,rui- \ .u f'1U'1Q,D J-O ·_·_ n1wa .-, . 1n ,~ axo•.- ooa J.a. 1'ib. 1MflMl•• i . nau.oa ·· ·«.t· .eciult"ioa a · • oa,-otly -. · i\ • -•~ ta •~•

wn evl4Hff4 ta, . a'l\tQ1 partttotllal'l.¥ r tJMt

~ a <:laf~ 11, ·m.r-etot"e, in 1 , o a o1a e u ·G:&o1 · i tH1 · ~ ·'1la p.l'o,ert.S..s ot .t1xa\1Q . an4 •~o.hans• ,P&eit. •

O'lAGJ' tluto1rka M V ... ·M YA •4 O:' .ti.at;1,,-11. .vm< a.,i•• lott• and xoiulll (l)J o. ·• folk

(J.S) .... ~·· pot;u.1 ~Sut.toa b .tUUIOVite fo~t.ioa ,u, 1H1J>po· 4 a_" x.-n, ,-"t••• ·r11e..e:t.1c _· .· ;·, ~AL• 1• JG• 1 bl · 16 tu»sW.tuttas _a aat p aaiua r o~ •illoo or · -. p x- •m• ~ - • C.lH&a"" (1-tl u1a.414 u. ~~-·,010-f.l •• -1.._ ...,. 'te4 \lith 'tu 1 ·(d 118 u 11 p l i , ·• 11:tt•aiti• dt,tr1.ag aPLl r1tnc JHNh+ Bffll9t\i~ . •• not r•siore 111• ao1l eel le , • orlt:1.n•l - Poa••• tiatloa ••• aot ,..••., ..10."• ,nll'1• la ...,1. SoLl& ,._...••.u. dx _,_ G~, $all. INUfa 0811'181- .,,_. ~ prl.Mdl,t to egrS.4'tu.fJe• ••~ ea,JlOJtJ·4 la W• •••.,. Gt \b:Q:H aolls Dal'k •P••l• 01~, t11vo•• 11.-,toa l a au._. ot t;~1 &•47• ~"• o-f'

Bia •1-v..- et aoil.a a•liffaU.t J-Hkea4 • tl.sa'101l ••e1\ r« ~k ~fd.ua G161' e., tie JJll• It •~tiu. f'i. ~- aftllf • 41ff..-.1a1 •t-a•• • na•t•i. ••1• f'1el4 eoll• lk4>W4 e:talla nm•••• w •b:·~1•«

u,~i. t.tx«itoa as .,,.,14-u. a,u o.t.~41.71•· Aa apt19oiab-l• Cl!liHla'I of JJOUJt$1Glll •• ft.~94 at ~ kiibd"t aJ:,U••1oa llfJ krJl llape.S.ma O'J.43' tUli! ~l iiuio ta._aol. orc~l"JUI 'l>iw S:u.alo ta:1rom te.ault,e4 1A uuall7 h1gll Uaua watu -, aY• JMtu ·•• oo ,_... Ql.t41\teaiu 0tme•a~ara1 lo, ,a•apiate ~•• uit Jd8fi ,a,er«•••• Ia tttw al'tff•te wit.Lea ue. bJ'U. pz.-••·• tae Dark ~l• Gla¥ l'lat u aaol\ ·U lf pe• aal 6t "1lt aMN

,fW,kht,ta. ~ -~ ...... 11.au.-..'

Qlt>N r•kU'.&lllJ waa Aetd ~ t1Utift U4 IN ~-. -..,--111 • ,ota•t• ••••& aot-.i., ,ut Ml u

,fff,O.flJ.~"• .-at. ftUUQA borM'*4 1'011!1 alpu ,...n,••• J., -,t fl¥#

Gla, ld.M'n18 __.. 14•Ut'14Nl lt1' tu 4ttt•no'tS&I

..-lN'...... --....,, ...... ·1 • ....-..... 1til'.' ·_· ...', ~....t. :,.,.·ilii# ~"-..... -~~.• •, ···-··- ~.~.....~,,...... - t"'1rl; wel.J. wlVL tllt a\a o,,i•tae4 1.u ~ - ••1' ~.-.•l•.tlU\ia la n• •taut.11 '* • u~tGS 2tl. J&\•l•t ~-. killW•• aa4. ,a t.n• oslrl ttl- •"

~a·- . tUll-, !A_ '.l*<~-t(...... _fi;i-i&, .-~_ _.. 1\01. """weff'awA~•..., .,.,..#',ti'.-"''.•A~A-il'k..,.._.,, 46

LITERA'l'URE CITED

(l) Abel.~ F.A.E., and llagistad, o.c. 1935. Conversion of . soil potash from the non-replaceable to the replace

able form. Amer. Soc. Agron. Jo.ur. 27: 437-44 $. {2) Attoe, O.J. 1947. Potassium fixation and release in soils occurring under moist a nd drying conditions. So11 Soi. Soc. Aner. Proc. 11: 145-149.

(J) and Truog, E. 1945. Exchangea ble and acid-

s·oluble potassium as regards availability and reeip r ·ocal r e.la tionships. Soil Sci. Soc. Amer. Proc. 10: 81-86.

(4) Ayres, A.•.s. 1949. Release or non-exchangeable potas sium in Hawaiian sugar cane fPils. U.H. Agr. Expt. Sta. 'i'ech. Bttll. 9.

(5) and Hag1hara H.H. 1953. Effect or the anion

on the sorption of potassium by some Rumie and Hydrol Humic Latosola. Soil Sci. 75: 1-17.. {6) --- 'rakaha sh1, M., a m Kanehiro, Y. 1946. Conversion of non-exchangeable potassium to exchangeabl e form in a Hawaiian soil. Soll Sci. Soc. Amer. Proe.. 11: 175-181. (7) Barsh.ad, I. 19.51. Cation exchange in soiJ.s: I

Ammonium fixation and its rela tion to potassium. fixE.i.;1on and to determination of a mmonium exchange capacity. Soil Soi. 72: 361-371.

) 47

(8) Bray,. R.H., and DeTurk, E.E. 1938. The release or pot.assiwa t10·m non•replaeeable forme 1n Illinois soil.a. Soil. Sci. Soa. Amer. Proe. J,: 101-lo6. {9) J).e'l'urk, E.E., Wood, L.IC., and Bray, R.H. J.94J,.. Potash

fixat1on in corn belt soils. Soil Sci . 55: 1-12. (10) Gerbunov, N.I. 19J6. Tlae m ture of potassium :fixation

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