,4t l rwul lural Water Men¢Jttt'mt'tH, II-; ( 1989 ) '2 I'~ -22N ?17 El,,t'vler =%_'('iPIICe [-'uhln!.,her!, B V, Am,.,lerdam - - Prmh, d ill T h e Nt, lherland~:,

Predict, ion of Sus ta ined Sodie Irr igat ion Effects on Soil Sodium Satura t ion and Crop Yields

M S BA,IWA and A S ,I(.)SAN

D,,partm,,nt ~1 Smh,, /"tmltJb ,4Wt,'ullur~Jl I. 'tm,er,,,H v, L, udhtana l Indta)

( A~ ~'epn-,d :1 , l amJarv IF)N9 1

A BS'F'RA( 'T

B a l w a %'I S a n d ,h..~,Jnl, A ,%_" , 19N9 Pr 'edwln ,m ,d',~,uJM.',med m.Jnr nrrngaln, m ,~l'l'P~'h.~ ,m ~.~,~nl m.Jnum ~;;.lltJr~.llli,tl LI|II"I i ' rqlp VleJdp; ,41lrl'c ~'¢.~l~'r Mana/f f ' , IH 21'7-2'2N

A Inch] Pxpernrr lPnl w.'.,~,, earrnPd i~ul f o r 9 ~,'ear~:; ( 19'79- I ! )gg )~ r t ,'J 'T'vl- .r I_lM~.' l ' l rept h~ nnvP~,;l q;,LHe I I~e iJl~l,,_,nJultl V id' pri-,dnelnrq. Ihe ~,.;ut;lLIir|P(| e l ' leer i~l nrr'nl.l'al t im wLtler~-, Vl:lrylrlp~ In Ni)rl l( ' l lV (i l l ~.,i)ll N~i ~,LllUrLIIIqm a l l d i'r'lq:J v le lds ur l ( lpr r lcP-wl leLH (R-~vV) ar|cJ r r l l l le l -whe~l | , ( M - W ) i,rl)r.p rq)l.'lll{~t|e4 S'~,nl N~J ~; ;J |utL l l l (m itll'reLl~.~e(l ()~,'er I he ~.,,eLIrs LtlI('I t he irwrl-,m.;e wa~..; hnglmr u n d e r H - W Ih;Jn urldq-,r M-%~.' i()l~Jllq~rl ,~l l ( ] l lJ ln LIdN(PrTJIlqm rLttlq) (:'I.~H m ), LIq~ljlJ~.;h-,rl %.,~F{,,, ~l l l ' l re!., l( lual N ) d l u t i l ( 'LlrJ~im{jJl, (R:,( i Wer(-' II1~ :.$UtluJJJe IrldtcLIh)r~:; i~l ~.ul exch.',lrlp, eabJe N(IdIuI] ' I JJl-,rcenJ~]u~(-, (F:NI-') F i ) r Jearhtlq.,, r{~l ldl l t {~n:. , ~ l I he R - W hv%Jern I I le el1"l[01rll'Lll i-'l.]lJ{.iJ IIHI I)l B ~ w e r el. ul wa~.~ .', t ; IJi I ;Jble i r ld l l 'L Ih~r i) i [,':,1' Fl~! I he M _~ l r l~t;Jt lqm, Lhe Rh~mde~.~ equ{ j j i ( l l l ,'1||1"1 I h e nll lql lJ' lecI Aver , , and Wl-'~;Jl'~| eqlJ,JJ I(~11 wef t , :,~Jtl~Jb[;-, in¢lu,~Jh~r~,~ i l l 1.2.;[' T h e ¢]ecl lr le irl {'ri~p vleh,:l~,.; Wll h ttl{'rPa~41nl~ ~; i . t t~' l lv w~J~ ITIt~r;-' IJrl~ |IIHIIH'PI'I U l l de r Jhe H %¥ r ld, 'J l t l lm IhLIt i iJtl i ' le|' {hi-' M - I ~ / r ldL . I l l lm I_l,:,lnl~ t he hee..;I I'll quLIcIr~JUl¢ r e l i l l l lm , . d l l ph t~J' qitJN(-qvPd v l e l d h Llnf"l LidlLiNh-,d !.,,~,l{,,, i(ll ' a l l Ihl-, I:J ~,,I-'Ltl'~; q~l' J I'll-' h l lJdV, q'ur%'e,4 wPrP i']l~J~.pt,'ll h~r r~r 'e(l l ( ' l l l l l~ t he n l . l r r lher i~J yeLIr~, J'llr w l " l l i 'h irr l l~LlJlqm w; i ler , ; , V;H"Vlnl~ i t l l..;qH'll('lJ v I'LIII ]JP iJJi~Jlt Iq)q~hl{Jlrl ;J d(-,hll'e(~l leve l i ) f i'rl~r_) .y ie ld

INTRI_)L)I t("T'l(_) N

In rm..~rIv arnd ,'.,ml serrlt .ar id r(-,.~t~ms tFle. avail;d:_ulity ~H' g~,,J quL.IIily w~..nl'.er us nnmde(lU;Jte and farmers t'mve t~ l ive wnLh the pr~ ldem (~t's~)dne nrrnl__,,~JLn~r~ water A h.lrl..,,er l 'utur~ ~lemund ~r'~ the Intuited water' resq)ur',~'es ~'an F)e expecte.d t~ fur ther nnl~'rease the usP ()t' r.)(Nir qualnt, v waters in these are:is. Suntahle manage inei l l lu'~wtu'es have, therel'c~re, I q~ he ew)lved t q~ eri,,.;ure hnl4h ag rwu l tu ra l pt'qJ du('tt l)r l evell w i th the use ~d' s(.Jnc water t'~)r urrngatn~m. The most i rnl . .Jrtant Stel~l., tn t hll.~ dnreetn~m ~nelude the detern~nnatn~m ifl' the sunlatulntv ~fl 'water hu' LrriI4atn~m, aml lhe devehqunent ~d' nndnrPs t lmt ear] be used I~ pr'ednct the t,unld up of N.'J ~n the s~ul as ~ resul l ~ff eont i ruJous sl)dnc trr~gati~m ~r dnfferenl er'~q) lung e,;vstenm. V,'arn{)us nndnces and empirneal equatums I.)r~)l-)~)sed s~) t'ar ( EL.It,tin, 195(), I I ,g ,gal~n.tv Lah~r~ to rv StutT, 1~,54; B~wer and Maas land, 19(;3; B~wer'

O:I'?N ;r?'7,4/H!-9/$o3 50 ~,_~ 1!4H!4 Eb.,evmr Sczeru'e Pubh,,her!., P, V

-~1~ M '; LI~ IX','~ ..+,".,I) ~, :, ;i~+,,,~+ ....

el ++1., 19i;,"+,, Rh<mde,,.+, ] ~ I ; 8 ) h a v e been le,~tPd u n d e r s teu( Iv ._,+late ('<mdirl(m.,.+, l i l ( i s t l v w i t h i ' i~rl lr l) l l<-'d lea( 'h i r lg I l l Ivm~meler ex l )er lmel l lP. l . M~I 'P rei 'entl~, ' prt~ p<l:.iel] indl( 'e.~ h~,' Miy, ' l rn l) t . ( ) (198( ) ) ,'.ln<] ~ut l rez, ( l / IS l ) have als~l n~lt vet b(-'ell lel.;tt.~(] In till-' r ieh] . U n d e r r leht ( . ' (mdl t l (mS in w h i c h a s|(--'a<l.v s ta te ra re l y <pl'i'ilr~; ( F r P n k e l , 19~-I ), t i re a l u ] l t v o r these eql. lal l( lFIB t(~ i ) re l l i ( ' ( miul N,u ,,..;Lttl.lr;_ltl+)ll ii(-'elI+.; r l l l ie evt+h. luted, t_)~.trllL'lJl;.irI.~,, w h e n s{ )d l r i r r lgnt l<) i+s are / l i ven t~l ('r<~p.~ <lir l ' .Prlng in l h e t r w n t e r reqi.llrP, lilerll.,-;

F,l'l'<-'rt.~; ~)1' !,+()<ll~: irrl~.+,;.llion~ <~n +.'ri~p .yieh.:l+ have t+ls~ I leen reported in l i t e ra t l l l e ( Bi)v+'er et al , 191;_~, Blrl~.]hLIrll (-'l LII., ]9'7<~); B~IW;I .el LII., ].,ch~:l, A.~er'. +, a n d ~,~,,'t-,+.;l('<)t, [ ! i ~ l ) , h u l ,,,-;iJrl'il,l<-,rl( w{lrk <.h)es m)t + e e l n to) h ; . lVe he t - ,n ( t i m e t<~ l i r l - ' ( t i ( ' { l he rtlle, ~lt w h i c h .yield. +, i l l ' < t l r rPrent <'rl)l)g r le( ' l l r le ( ) v e r I he .ye;..ll'~ (tiJe l<l 1(llll2 , t e r m irr l~al l<_m w i t h .~()<h<.' w a l e r , u re te r <h rfe re r+ t (.'r<~p r'(_~tallq~li+,+ ,~t.lL'h in l ' ( i r i l l a l l i ) t l ii.; [lel'eI..:I+.-;~.l|' v I(~r e l ' r l r i e l l t ill,'lll;.t~_~enlerlf ~ ) t ' l , , ) r ql lal i t.~, water.,.+ .".;ll t h t l l L1 I~[l.',h + l~r l r l l l i l l r+~ l i_)rl)dl.l( '{ l(ql i~ i l l , ' l l r l t , ' l ined

T h e [)re,'-;ellt h)n+ t e r m experimeni" warn <';.irrled (~tJl u r l ( l e r h e M <'l)11<JlJ iii11~ t~l in~, e:-,{ll.+,tlle {hi-' [J<im+.+iI)iI~t~ <~I' r~r(- 'di( ' t lng m<)dlr i r r i g a t ~ ( m el'r<-'rtm ()n ,~<~iI N;~ ,,.-;tit i . i rat l i ) r l a n d un .Yields; (d'rr~)l.)s 1.7,r<_)wn u r l d e r h-';+('hing L'lml"ht I()n+-] I l l ;_t r i r e (we t l u n d ) - w h e a t a n d u in i l l ( - , t -whet+ l cr4+l:.) r ' l+tati~m

"~IATF]FIIAL$ AN[) ME,'TH<.)I),_g

'T'he t leh l ,'-;Ill<Iv wu~.+ rdmduc i ' ed rr~)m 19'79 th r~ lugh 19H,8, q)ll 3 we l l d r~ l lned ,~;UlUtV h m l n Sc)ll (T .Vp l r I . Js t~ rhre l ) t ) u l l r l P r l a l n tp~ ml t h m m at t he e x p e r l r ~ l e n t a l s l ; i t l l~n il l ' l h e PUnl;_ll) Agr i ru l tura l I_]nlverslCV, L i ld t l lnr+ la, I n d i a . T h e ()- l~()(u'Ti :.,f lJl l)r'<ffile h a d a p H ,d' '7 ,r, t~ g. 1, z_mr+ ele<.'t rid't+[ r c ) n d u r t l v i l . v < ) l ' s a t u r ' a t e d P s i r a f t ( m< ', ) +)i'<1.4 t<, I) M d S / t n , un ex rh ; . i nge t t bh - ' ,,...;()dlllltl r+)er(.'<-'lllt.lge ( ~ll+[' ) llI' I.HP--2 l), '+I < 'a(_'(_).+ r ~ m t e r t t q_ll' les+-; t h a n [",',, arH'l a n ~ r g a l l l ( ' +.'a rlJ<m l ' imt .e l t l ~I ' I ) L! t.~)l)i+ ~ ;, ' l- 'he (.'J+_t~,,' t ' lmh- ' l t t ( 1'7.-I to ',..+'7 ()+'~), + , '+ lurat l (m j_)erL'L-,nt;ige ( iJ l t<J ,",t<'; ) Ul+ld (.'al i1~11 ex('l l ;. l l l~.P I'Ltl.);l('lt',,' ( ( ; .J l(~ ].-1.,~ r i l e < l / l ( ) ( ) ~ ) , d ' l l l e mill] iil<'rea,,-;ed w i l l1 depth 'rh<-, l.,<~ll wa+:+ I'alrl.y p e r n i e a l ) l e h~..IVll'lg ;_! t'111;_il i n l ' i l t r a t l o n ra te 4~1' .-I.'! ( ' l t l / h "ri le, wL i le r ta l ) le at t he e '<per ln ten t , ' l l ,'-;ill .+ alwa.v,'-+ rel+nLIIIl(-'(~ beh~w l l ) m ( le l~ lh. ' ] "he u ve r'+l+~e wee k lv rt l] Ii fa l l a n d r I+.~mm A l.m rl ev;Jl.)~ i r~t i~ m (hJ rl ng A l~ri l , L9'79 t~l A l ) r l l , I!~H,,~ i+:+ i.,,iVel~ in Fl+g. 1 M~)re th~lr l '~'()+';, q~t' t he rt:llrl I'(-'11 dl . l r l r |~ ll-le ITl<)l lgll l) l l I-;I-'HI.;<III I'rillTl t l~e end ,d ' , Jur le l(_1111( + l legll lr l lr l~, ill ,~ell lerlr l l ler , di.lrlrlp, w h i r h l_)e r l~ , l eva l ,~ra t l< l l~ wa+.; h )wer t h a n rainfall

']~111-' i l)VPM I.L~,Ltl i()rl,'.+ were ( '~l 'r ' iel l Ill.It W i th ,"1 I'lL'e - w h e n i { I+'et'erre<t i l l ,'1~, R - ~," ) ;.ind a rn~l lel - w h e a l ( re lerr l - ,d I1);_'IX M - ~,~, + ) i ' l l t a l l iU l ~-~+..'henle, ~'{mllTl<mlv t'<_llh ~wed i l l I l l e re~.,l~lll, in ]..'7,+~, ;! J,", in'-' I_)l~lt+_-+, ,"-;ellar~-Ite<l I1%,' i.)+)lyeth.vlt-,lle retie'elf; I<);_1 ({el l l t ' l ()1' I I l l . '1-'he irrl~_+,;ttl+)ll w~l[.Pl' lre,'ltlller+llP.; inl'h.l(+e<~ ;.i gl_){)d qlh'_llll.y t.'all~ll WLller ( l 'e l 'e r red i l l ;.11.; ("~,V) ;.Jlld f ive ,.~t.tdll' W~.|lel'[-; (rei 'er l ' led hD LIK ~ W I , ~ / , , ~W.I , gX+'V+ ;_11111 ,~,~,~,I ) x,;..iryir+l~_~ I l l N , l l l J l n ~.tdxl)r l . l l l lm rz..Itll) (.~AR,,~.) +lnl l res ldu+l l a l k + l l l n l t v ,%_'llrh L.v]_)t-'s i)1 w,'.ltel'P_.; LI'ILll Ltre i ' l)l+l-lrll<+lll%, ' i~H.lnl ' l II'i rl lt l l]~,, ar ' l< l ~ t l ld L",(-'ITII ~_Irl(( regl(m,~ w e r e m.yllthemi'z, e d h s,, ad(Jir1~ N~IH( I(.1:~ LIII<'I N a C i t~, t i le ( ' a n a l

I,R FI, DI( 'ITIll F',+ ~ IF F,q )r)lq ' IHFII( bVT l( IN F:I-IF'F:I"I'P~ '.~ I~-)

li-

;i M(

ill (d

'1 -I 4II -I

I~ J( I ,J

L] F.,PAINFAI. I. I -VAF'( )RAT I( )PJ

',.t ' - ' ' - '

Fig I At.Iel't.ll~P w l ' e k l v ('ll,.,I r l b u [ i i i l l i l l I r a m [ a l l a n d I - 'var){ i ra l i l lm ( nl<-,an~, I~l ',hJlv ll.")'7!-I h) A p r i l I t l8N )

T A B L E I

( "l ~rrlr)l re;it 14 ii1 4 )J I r r 112,1..ij ii )rl W+.lle rt,,

( "l-la t+4<'let iM leM (~ t~,, ~ W I ,~W,, ~ W ~ ,~IvV £ ~t~, , ,

~h - i l ' t l l i ' b l I 4 ' IH I f ' I I J ( ' I IV I I y , F:<' ( f l S / I T I ) 4 ) ~ I e;(I I t';() I ,4~1 141) 1,411

~ ( , h J h l P +,alh., ( m~- ,q / l ) ( ' a ''+ I h I h I 'J ().M

( ' a " ' + MI.,, '+ ~ 4 '2.4 2 1) I +;

N a <) ~1 1'2 '2 1'2 4 1'2 8

I'i_)'~ + HC(_)~- I 14 4 M '~ 'J ~l 1' I I ) 4 !-I 8 'i 4 ,4 U p H , I' ' 7 N() 17 e;I) Ip I+~) I 7 '1~ )

F~l-iMl('hJul P,,,)duum i 'art) ,~nal.e, F+N< ,i, ( rr l l~q/I )

'2 4 !~ I 7 t;

() +; () ;~

1.4 I J ;I '.~ I h l I ,-I I+; (I

'7 .-I() ; :lq)

i) tl 1,4 }4

S41dlUITI alJ+,,i~rl)lll~n i 'at l l ) , ,:;AFt' I) 4 I I ,1 12 I 14 ;I Ih ~ 19 h

" IJH, = 4 I:)h., - pl i , ) + p( (."a '+' + + M g +' + ) + p ( A I k ) w h e r e pll.+ a n d pk, a re I he nPl~.'+l iv<+ h~l.;ari l.hn,., u l IhP ~,,P<'fmd <ll+,m)rial.u(m ('qpn:.,lanl qbl H;,("(.)~ a n d the m)h.Jbuhlv q'q~n+.+l.arlt ~pl' ( " a ( ' ( ) . , rPN)edu ' . 'e lv , hqpth q'q~rr'P~'lP+l h~r , m , ' '.,I r~uil.,,lh, p ( C a " + + MI.,, v + ) an t i p ( A I k ) h(-,ung I.lle ne fga l l ve h~l.,,ard hm+., qd' Ih< + mqdar vqmc i+ rd ra l i qm i~l ( ( "a '`'+ + MI_.,, '.'+ ) a n d tu t . ra lab lP ha+,,i + (C(.i'~ + H C ( ) Z ), re+,+perluvel,,' ( F'h+wer I-,I al . 1!4+;~ i. +' I.+!,~' = (('(_1:'~- + Hq;(_).; ) - ( C a ' + + MI.',' + ) (a l l <'al uuIP.+ a n d .'+ru~m+,; m m<+q/I )

' :i,+,1~,,, = Na +/~, (< 'a '`'+ + M g " " )/7.! (a l l ra l .m+. , in m e q / I )

water (Tuh le I ) The v.'+lue,. +, (Jl' SAR,,, a(JjLiMe('l (r<-,ferred t<, us adl ,"+AH ~nd a(.li R:...+ ) for the efl'evl, o f <'<.,mpt)siti,m ,)I' wa te r ,_m lira<-' pre<.'ipltati, m and ,li.~+ molutlqm were culeulal,ed using the t 'olh)wing t-,qllal,lq)rtm.

ad,I.~AI-t=,~AR.,,, I I + ( 8 . 4 - p H , )I ( B o w e r e t a l , 1968) (1)

a<JI.R,:., = N a / v ' ( C a , + M g ) / ~ (Ayer8 an<t West rq~t, 1,~)8f~) ('J)

'?',]() M "; B,'-=,I~A ,~ ANL) ,~, t, I( I',A%

where ('a, ~s ~'aJclurn I11 =rr=gut~.m water r'n~.t~f=ed hv sal in i ty , HCt):JCa r a t~ ~lrld part ia l r.)re,~sure ~)l' (~I(.) ,.

~verv year wheal ('Ft'H~'um oe,,~/h,um, (."v W[_, '7i L ) wasgr~wn t'r~)m the rtrst week (d' N~wennber t~ the t.hnrd week Id' Al.)r~l and IH~th rnce (~rv,.'~.~ ,~'~.~tit.'n, ( 'v. PR It)l;) and m~llet (Pmm~.s,,tum tvph~nd.~, (~v P H B 14) rrum the I'll'f4{ week ~t' ,l~llv I~= the end (d' (.h.'t.~d)er. A basal (Juse ~i' Ihl) kg N, t;I) kl~ F'v(.)=, and t;() k~_I K ,(_)per ha wag gtven t.~ I,~lh rice and wheat, and 1()() kg N anti (;i) kg [-'.,(_)., per ha h~ mtllet as urea, dtanirnun=um ph~sphateand I_)~tasstum chhu'tde In a,I d=tum, N) kg z~rH' sulphate per ha wag aJs(~ given fit ever.v sec~)nd cr'~rJ At e~]rh trrtl4ult~il, it() mrlrl ur water was applied Bel'(~re trar]sl.)lanltn~g ri~.'e ~seedlir114s the ~_~ul wa.,.~ submerged an(l puddled twice t¢~ reduce the salur'aled hydraul ic ,'~n ( ]U ( ' I iV l I y ~)J' t h e Sl)lJ. Rice wag gr i~wn u n d e r sL ib r l l e rged r, mrhtil)n.~ gm.'h t r e a t merlt wag r'epli('ated l'~ur t imes in a rar]d~)mized hh)~'k design.

~verv year ~_~utl sanil)les were c~llected l'rl)m each l-)h~t w i lh a 4 crTi ( l inmeter ;.llJl~er i'r~in ()- ],~ all(~ 1~')-~()L'rlrl del:)lh~ in t.he th i rd week ~I' Apr~l. In 19~,~, s~il ~.;aml~le~.~ were alsu ~'~llecled l'r'um ()- |f), II'~-3(), ;I()-H(), (;()-[-)(), 9()- I ',.J;(), 13l)- I~')() arid I N l - l g l ) ( ' m depth.,..;. The sarnpNs l'r~rn :111 the replwat~<ms were ~'r'liXe<J t<~ ~btatn r'el.~rel.~entattve sample+.~ l'l)r each t reatmenl. They were air dried, ~;r'~)itnd, pas+.;edlhr~it{4h a U n~m sieve andanal.vsed l'<~r pH ( l L ! s~ l .wa te r ) ,D ' , . an< l ~..;,~.[4 ~I' the ~_-;~.itlJratl~)rl extra(' t (,"a, AR,.) ~.I11("I E~I-' Jl,y l'Idh~w~ng the rrletl1~)(ls pr~ l)~,.'.;ed Iw t i l e (_I ~. ~a l i i i i t .V l.,ab~ratl~r.v 9,tarl' ( 19h4 ).

R b].'.a,I I I.'T',~ ANFI 1)15("1 I~gI(.)N

Su,~tatned trrJguticm wit,h dtt't'erer'll sucliL' waters increased pH and s4,.tllmt ~:;aturutlqul in the sc~il under h~pth the R - W and the M - W c'r~pp r~tall~ms (Fig 'J ). The hllnld u.np i~l's()dnunl was higher n11 the sunrt'a~.'e layers anll irl('reased wtth t nrrea:.~e in ,gAR and FIg( ~ c)[' ~rr'igatil)n waters, go~l .s()dilJm sat.urat.i~)n cle~'reased wl th depth and the rate ~,l'declJrle wag rot)re pr,,rl~,ur]~.'ed under ,gW.4 and ~W!, l re[ l ln lents C~mslderable leachlng ~I' s~,:lium c,'~.'urred under ~Wl , SW~ arld ~W.~ I reatmenls, parti~.'ularly Jn R.-W rq)l.at.i(m, result.i||~ in appret'tahle tn ~'t'ea~se in .gAR,. and P.,.gP in t.he deeper layers ~)J' t.he sc)il. H~)wever, urlder ,'g~v' 4 ~i~(l SW:, lear hlnl.; ~d'sudium heh)w (;() ~.'m depth wag rather small and, t herel'~re, the l,Jih:l up ul' F:._gl-, wag ~)nlv sltlghtly h=gher than t.hnt observed ~tnder ( 'W I r(-,ut merit. Under t . . th ~.'r~p r~dat, ions and all sudic ~rr=~at~un water' treat ment~.~, pH and ~()(]ll. l l l i saturat.=~m in sur'ra~.'e slul ~m'reased pr~)p, resswely (wer t.he years ( Fig. 3) The im'rease WaS q l J l l e sharp at. higher levels ~d'siHhcit.V in wafer and url(ler R - W r~tat.i~)n Thins h=gher aci'umulat.lOn ol's~,Jlurn in the s~iI wag d~le t() lhe hil.~,her alni~IJnls ()I' :~,()llltll'rl :Ind ('arblmates added thr'~)ugh a larger n~im l)er' ~d' irril.,,ati~)ns c~unl.)ared wi th th~)se Ullder the M - W r~tat.ion (Table L! ). The E,'4P vahje,=.~ ~I' the ;surface (()-(;() i 'm) s<)iJ were signlri(. 'antlv related wi th ,~ARI, ,

1'14 F:DI( '1'1( iN l iF' !,;i }DII ' 114 RI( INT'I( iN E F'F"EI "T'I', '2'2 ]

f ) [ : '

r l ( ,

i

INL

pH ( I .,' '.:H )IL WATI_-R ) M( 14h I-If) '4g 1(IO 7 ~] 14(I

t I k [i .~ ~ ' i ' i ] i

,%, .- ' ( W ,, --,- ',Wl + ' , W d

", '<t"#1' I~ W - . - '_,Wt - - - u - '., Wz ,

r) l() dr) ~) zg;

ix - W

I.M izi

' ] A I'~ ,.,

I~ i '7'f,l "'i ~ ' P , " i

", M W

II I;

12

1,1"1

',, , "i !"', ,'<,'

~ M - W

I- '., P )() z'(] I(] 4() ',(I (¢) (} T() 21l t~) . . . . . ] '~L ', ' ,l' ' - - ~ - - ~ I '

F'q4 2 ,'g~HI p H , .'-;a r% a n d E',!.;I-' u l l ~ r nmt-, ~,ea.]r!., ~1 l . ,uHtnlne¢l ~.;quJB' Irr4.,,att~m

(r=(}.!):l'7++), adj.,'4aFt .... (r=().94!-)++), and ad.i.Rn., ( r = ( ) 9 4 1 *÷ ) and tt,~c',,,. ( r=(1921+÷) . T h e E,'.,IP vahJes were also stgntl 'ncantlv related with ~AR,j (r =().9,.w,(I ~ ) and pH ( r=( ) .965 ÷~ ) T h e w.~lues uf ,<qal% were, however, hiwer than thuse cd' E.sI-', i r respect ive of the sodtr water t reatments Thin can be at t r ibuted hi the p~lsslble release ~fl'Ca in t.he s()il suluti~m due |~l the dismdut4(m ~d'(_'.aC() ~ and Ca pr imary minerals (Frenkel and Alper~wltrh, 198.4) whwh in tiJr'n hlwered the ,qA[4~. values.

Th~ fc, l lowing empir ical equathms, inw.dving s a t . . . . ad.i.gA R,,, ~lr ad.I Rn, wer~ used t.~l predict the bui ld up ~ll' g.'qF, in the s~Hl:

l SARd,, = , -- 'ad. i .gal4 . . . . (Bq}were ta l . , 19(18} (3)

\ . ' L,F'

~ ' f I +~1 , [ " )

~ARd,,, - , - - ad.j..gar .... ( R.hclades, 196~) (4 } ~ " I , F

wher'P the vahJe cd'" ~' " (mJnernl wear.bering c~lel'l'ictent ) wns takerl as (I 7

Na " / - - - / ,'qARd, ,, = - ~ Ca, (SlJareg, l g g l } (,D)

I'!"-1"-I I~l ~, BA,J~%A , ~ N D I~ ~'; ill )~11 ~ r,J

( W - ~ - ' , W I . . . . . ' W I . . . . i ' W 4

- l - . ~_~W2 ~ ~:~Wr~ FJ__W . ~- ,,----,,-.-~--,,---,

IlZl '4 (} " ~1~ ~ ~ - ~ a ~ --"~

- i ' / ( . a u ~ '

,7, 1() f) I M W

7 ()1, i ~ i , ", . . . . IqTq 1~4~ I 1~"11~,.~- I~L"I/-., P#'I('~

H I II I S L', 1~'7

2 ( ) - ~ .~-.._--.--- . . . . . . . . .

Ill

,(). ,,-- ---~.'. _ - ~

{ I I ~ " ] ] I } "l ~ ] I I

Y i- A I:~ '.,

FIR 3. ,gucl'e~m,,'e i'halil.,,e,., in pH and B'.,I' Wll h lime, it| h~p (F-3()~'rrl ~.,l~ll

where Ca, Js the same as in eq (2) and all caln~ms are it1 mm~,l / I

1 tSAR,t,, = -- 'adI.Rr,,.~ ( M~dit ' led Avers Lllld W e s t c ~ t , 19, '4h) (t ;)

\ I,F'

,qteadv state ('~)ndlt i~)ll,,.+ were n<)t a t ta ined in the ()- 18() elf1 s<bil I.md'lle ( Fl~. 2 ) i lnder I)~pth rr'q)Pr)lng ,~v,'~tem~. These e(.llJati{)n~ were, I'll)wever, used he<'aLise d t l r ing the last tw,~ years ( al ' ler tggi'; ) lhe rale.~ ,ff in<'rease in pH tt l ld I~',,%l-' ( Pig. 3 ) t ) r t i le .,a, llrl'a(,e Sc)ll were I 'a i l ler smal l and hent'e it. Wa,S l l+~lJrt led that a qI.ILISl stahlt, +.,air halan<'e had I)eetl at laine<J in lhe .'-;url'a('e I+.ver (d' the s<ul

rrahJe 3 Jl~sts t i le observed average F',,b'l-' vnJue~.~, In t, he I<~p ( ) - ( ; ( )cm s~ul and

th~.~;P qJl' SAt{ ..... ~.ti ~ A R ..... ~_ldJiil~)N,i and SAFhj,, values predic ted by the al)cwe em pi r lca l e~luatl~m,.,s. W h e l l the SUltahl l l ty ~d' the equat ions I'(br [)reiJli. ' l I t lg I~',,~,F ' Ih ; . letel ' r l r l l l led t:_)v ('l(),'4etle~S~..~ cd't he oh,gerved ,'11'1d predicted values, ,'4A R,,,. and mtl R,.,j,, (e( I 2 ) ~'ann~_fl he c~msldered t~s SUll.alfle indlcat.~m.4. The adl.,gA R,.. (eq. [ ) seemed 1'~ I)e m~we mJital)le pa r t i cu la r l y under the M - W rcfl.all~m. Unde r lhe R - W

I'RR[)II "1-1( l% ~ II.' ~:.,~ )[)1( ' IR[-tl l iA'rll IIN F',F'FE',(' I'H '.~',!~1

T A B L E ',~

'T',,l.',l d e p l h ~I' irru~at.=~m, raHd'a] l and ~'la~.~.~ A p.',n l-'%,;..ll.)~)lal.l~lt| va lues l.'[iJrlnl.~ , ,July l!-rT!) h, Al:,rd I!-)HH and al : . )pr~xlmale lea~'hlnl_., , t ract .ira., cah'ulul.ecl ])V e~.cluchnl4 the Mav - , hJne per l i . : l w l l h~HJt ~'r~,p and nrrip, nl u~n

,~,)lJrl'~, ,d 'wa l+ r "r~dal (c rn)

Irr q.,,al,m (Jw) 13,44 .444 R a m l a l l i rw ) ,~H'7 i~'7 'T'~lal waler ' li'IpUl, (lW "l" rw ) I!-)31 1031 Pan e',.,up~rnl Ii)n (r,P.) I()3..I ll);l..l APr_)r,~x~mal.e w a l e r h~.,.~!.~ n e ~varJ~)lrrm~q:)nr~d (~'w") ;"i'7,4 '7'.2.-I Ap lJr~x In late depl.h ~I' wu te r (Irair, ed 4L'Iw = lW "l- FW ( 'w) Illh'7 31)'7 Alarm~xum~sle leau h ml.,, f ra l ' l l on (I.F') = ( ] w / ( iw -I- r w ) ) I) ;~.]'7 (I ',..~llN

61;

" F~ ~r ~'ah'ulal m~,.,, " u w " . t h(, r,l]: durung r li'P 171 ~wl h wu~ n'lult q.d u~'d I)~/ I i) and durunl4 mdh ' t tJrlf] whea l l.,,r~wl h hv I)'}'

'T'A B L ~ :~

(_~)rnlJari~.~m ~1' Ihe ~vera~ , ~b~.~'rved E;~I-' value,~ in ( I -H()crn I.,~HI, de le rnHrmd a l l e r !-t re'at!..',, w d h !JAR,j,, value~.~ r~Jiculale(l iJHlrll. ] prP(l i~ ' l . jw equal.,~n:..,

'T're~Jlrnenl~, ()b~.~ervl, cl !.;AF,',.., ad I .'.IAH adl /~',~,, Pr~dl~'t,~cl !_~.~,Fld,, , F'.,I' (eq I ) (eq 'J) (ll-(.-~(I i'trl ~l)we, r F'th~)ade,:.; ,~IJLII't-,'Z. M~<Jllue~'t ~-,)nl) i l~q :t) ( e q 4 ) il- 'q .~) A%,'Pr:~

r|l]

l eq fi)

I[iJll'4'- II'h~:'12{ rrJh]h~Jtl

,'4W, ~.Jh I I 4 ',-~() I, 1" '7 ~'7 'i' 131 I~-Jfi 1'7 I ~%'., '2~!-I I'J I ',.';I t; I.-I.() 31.9 11~4 '21 I I~!1 ~%,A,' ~ :l;. i-; ILl 3 U~ fi Ifi 3 ; l~ '7 17 'J ',2,4 i) UU () ~XA,' ~ 4;I.:t 15 ~ 31.1"~ 1'7 t'3 ,4;I. 1 I!) '7 L~;~ h ','3 H, SXA,', fiq) I I!).;~ ,41 () L~L ~ h h h ,4 L~ ,A 3'2 I ;Ill 4

MIIh't-luh,,¢~t r . tahrm

C W '~ () i) 4 IL'? (I 4 I '2 I) t', fl !4 1) fi ~ , " ~ I~:) ;I 11.4 '~i)h 1'2'7 3 ~ h 31 3 '2!-) I '~3 ',l

,%W.~ L~'7 4 1,4.3 " ~ H IH :l h'2 4 LJ'7 !) 34 .4 '7!-1 ;'.4 ,~Wl ~9; I I ;p~ 31 6 1'Tfi hM,l 3 1 X :ll'; I ;17'. ~ ~%' , 43 .-I 19 ~) 4 I l) 'J'~! h 71) i~ ,-I(I 4 4 ~ !-) .] I '.!

r'~tuti<m (l,l~' = q).~'~.-l'7 ), [hie ~)b~erve ,d F,~,~T-, value,'.+ were f;llrJv ,l'hll~e t~ the expe l ' t ed ~alue~ ,l'ak'ulaLed by lhe Bc~wer equali~m. The E',,~I-, values pre,l'ln+.'ted l ly lhle l~ t,i< m,l.le:..+ e,l.lU;Jt i~u,i (eq. 4 ), the ,"4uarez equat i<~l,i (eq. ~:~) al,id the it,l~,ltil'le,iJ Aver~.', ;tlut We~tvq~t equatl~m (eq t-~) t i l r l h e R - W r<~latl,lm, were,l'qmsl,lleral)l.v lower t tlun Ihle <~lplserved wtlue~., I_/mJer t hlis ( R - W ) r<Jtatlqlr,i, ir,i,l'rea:..+e =,l,i i. lurtlal i.ire:.l l.lu re ,,t ('().,, ,lleL'llne in i.i1-| ,~[' the a lka l ine ,.,soil :tnd inq~hulrz.atl~m qfl' (_'a I'rc m't l.+<ul mllleral++ w l t h gl.ll)ll,iergen,l 'e ( P ( ) l l t l a l r l p e r t J m u , 197L.! ) ,lJurll,ig rl,l'e , l 'u l l l l re ~'<)iil,ll l~e PXl~el'tell t<~ c<mt,l'~l thle l , J i M ull ~I' Nit in t h e +<~iI l -hl lwever , ll,i t h e pre+.+er,lt e X l l e r l l t l e n l t h e atln<~utlt+ ,l~I' N~ ,'JI,ll'[ ,l',51rl)~l+,l;Item lit'hie,it th , l '~ugh ,'_I large l lUtt l l )er ~I imp , at i~i,lg ~n t h e H - W r~itul i~I,l w e r e l~i~hl h i m ('t~ t'eleLl[ged l't'~m~ s~iI mln+,rah.+ wa+.+ pr~Imhl,v i,i~t el,i<lughl t<) m~,Jil'.v t h e l lu ih l UlJ o f l~',gP iii t h e +lllI. In +~,iJ,l'h ('<)li(]lll~)tlm t i le l~<~wer eq l l a t l ( i n [~redi,l'te,lJ thle I+++,'+-;,I' l't,iirlv ;_,l,l',l'ur;Jtelv l~c<,t'p<~,l'a l l<Ul (~l' ;I m i n e r a l w e a l h e r l n g c(~el'l'l,l'lel,it il,l t h e B o w e r eqlJdtii_)n ,l 'emulied ll,i Llll i)Vel'e'+tllllUtll)t,i i)I' l l m e +,l~lublllty ;.,it,i,lJ hen, l 'e thle P,~l' v+ll.le+ cah 'u la t e , i J l~v t h e ~hli~ade~; el_ll.lali~)ll w e r e ,l. '~msi,lJeralfly l o w e r tl,ia,n thle ~11,iser've,ll Vail_teN '-rile ;Jlm~Ul,lt i~l vah l ' l um it,l i r , l ' igt l t l~n wLller nl~,dlfle,ll ((_'~_.I,) ILv +.+ulIt,iItV, t h e ImrtI , l l)l'e'+._+~tlre ~)I' (_'1_)+, tlr,l,ll t h e H(J(_)+/(_'a r a t i ~ w e r e <)x+,el' l~redl,l'te<l l'~r t i le le,'J,l'hllll.,, ¢'~luliti~m+.; ~fl' t h e F+-W ,r=fl;ttloi,l a lu l , t he , l e f l ) r e , t i l e ,~l.lare'/. el.iiJ/llltlr,i Ul,lll t h e i~u,dll'led A.vPt'g Hlld We,'.;l,l'<~t e,l.lllLltll)n l.ll,i,llere.h_'t ll+lILlte,lJ l h e K:'IF'.

I_lll,iIer l l le M - W t'i~t,'Jtl<)tl, the g,,4P value+.+ c,::lhuJl;Ited l)v thle' Ph l we r el.lU;_lll<it,i we ' re ~'~m~i,l'ler,'Jlllv h l i~her thuI~ t h e o J l s e t ' ved IZ,,+4F' %'LIILIe.'-; It,l thI+., M - W r~t;_,it urn, I.I-, x~,'~.l+.+ h l w e r ll,i add l l l~ t , l t~) t h e h)we'r ;_lll,,.++)hJle al+l,i~)iJtlt++ (~I' N;.I tll,id I'LII'I_)+)I,ILIIe+4 Upl111e'd tl,ir~,J~,l,i ir,ri~atL~m++ P o r [hlege' c<mdl t l<m~, t h e Blower ' equLltl~ill IJl l l ler e+.+tilll+Itell t h e lll,ile +.+~d~Ilulit,~,, (():+te,l' unl l Rh<h:Jde'+-+, It)'7'7) ttt,l,ll h,l'l,ii'e (IVet'e++ll lllLlte'll the" ~,lli,l'itv '-rJ,ierel'<)re, t i l e ~hiCu_,l,lJe+ e q l l a t i ~ l l ir,lv~flVlU+ ,u m l t l e r a l we'ul her lng ,l'()el'l'l,l'lelll, [hie ,~,l.i,:lrez e',l.lllUt iltn Lll'lll t h e nu~,dil'~ed Ave',l;+ ~.II,ill ~,~'e,,.;t l'l)l equ,'Jlil)l,i il,lV,llJVlll+ ('~I, l 'a~rlv Ll,l',l'ur;_ttelv predl , l ' te lJ l h e F:SI'

( 'i'Ul I vnehl de<'Iit,ied w l t h ++~,iI~v i r , r lgat i~m ai,l,l'l t h e h larml 'u t el'l'e<'t++ we're' ll'llll'e l)l'+Ul<)[lll~'e(I +II h i + h e r l e v e N <~l'++~,dlcitv in WLIle',r. '-rhlm II~..IN hee 'n ~l,ll~wn t h r ~ u g h the" lle'+.;l flt ilUaIIr;,iti,l ' re'l~Iti<)l,i.'-+hilps l~etweet,i grLll,l,i Vle'M+.; LIIºIFI ~I,III.+-;AF+ .... ( + '= h,~ + l~i~ I + h , ~'I', whle're +' u_-+ grall,i ylel,l'l, ~i l+-+ a,lll NAIl,,,, and h,,, hl a m l / i , t.lre" l h e rf'~._~I'e'NEH()II i'~)el'l'l,l'le'r,lt+-i ) irl '-ral~le 3 '-ri,ie v a l u e s (~l'l'i~el'l'iClelllS i f l ' , l le te t ' rn i l la t l<)I,l (h ' " ) we're" hlghll.v ,'-;ll.~t,iit'l<'L,ir,ll +,ll,i(I the [)re,itl,l'te'lt .viehtm were I'alrlv ,l'h,.+e I<, the ,,l~+.+e'tve<l viehh.i '-rhe'rell,re, I'r~m~ the IIre~tlCle~t vleht,~, l_lervent rehntlve" .vlehl+:+ (ke'epil,iI.', vie'hll.'~ Ul,lder ( ' W u+.; IIH)) were ,l'uhl'~llale,lt a++ :.+t,i~wn in Pig + It i!.i e'x,141el,iI lhal ii'rel_~pe,l'llve <~t' the ,l',l~p, lhle ,l.te,l.'re'ame il,l .Vle'hlt wag :+mall du r ing inl l i;ll velars ;~t,i,lt at h~we,l' levels ~t' l_~odl~'ltV ( g W i +tlUJ ,gW., ) <ff lhle waler Witl~ :411['it Llllle'll ll'l'Ig;ll I~ltl <)ver tile' +'ear++. Ihe' ~le,l 'llne I~e,l',:.lltm r;.ll hle'r mhla rp ur,ide'r ,~W+ ;Iii<l ~W+, ,'_l,lI~ II,i [~-~V I"~fl;ttL+~r~ '-rhm l~mV l~e u,,.+,l'r~he<I I~) lhe" pl'()I~IIe'+:;+41xIe" ll,l ('lIe+l+.~e" 111 +~4+II +.i~ulllltll I~LIIUP;.I[I()II Ull,lJer lhle tx,'v(~ i'I'~) I) r, fl,'Jtlon+.+ (F ig ~+) 'rhle ~' le ld l'e( h u'l i( ~l,i ~i' ,l'l~'e' x,x+'tl,~ v e r y ,h_'l m ilu r t~ I h,'.,iI ~ i w hle+It u ill[el' I he" I-~ - W r'( ill_It I~ ~t,l <h_IrII~l:, +_Ill tl~e" .v e ;_I r,'-; . 'Phle l,i,llllet vleld,'-; w e r e l,i~fl +.,L~,nil'i,l'antlv al'l'e,l'le'd hy ~,~uliv

I ' I tF,,DII 'r'l( )N ()F' l,;I )D I ( ' IRR l l ',A'T'Iq IN E,F'F'F,( "T',S '2'Ji)

'T'A B L F', ,I

Rel4reP,nn()n r()el'fni'n(=nl,!.+ (h . , h, a n d h,, ) a n d (',)el'lwnenl,n ()I' det ,ermnnal, i()n (h ' " ) h)r l,he quadra l , nv t-,quali()nn fntlerl h ) l h P ,L,)"ra in yi(.-'ldn (kg rn-" ' )()I ('n)p=+ ( )b tanned durnnR dnfferent y e a r n

'¥e,J r F-{ i l 'e - w II(...a I rq)t,al,i( )n

R . ' e W h e a t

h. h. h,, h'" h,, h. h, h'"

1!-)'7!)/H() ( ) t ; ; l ( ' ; I - ( ) ( ) i t ( I t ) ! - ) - ( ) ( ) ( ) i ) ( ) ( ; ( ) b i b ' " ' ()~)Ht;',.) ( ) ( ) ( Ib l ! - ) - I ) I ) ( ) ( ) I H ( ) 'T i )H ~

I ! ) H ( ) / ~ I ( ) ( ;1 '2 : ) l),()q)~)(c)t) - ( ) ( ) ( ) q ) ' J ( ) ()'.')4q) ~ () b()!')('; ()q)(l!)(J'7 - ( ) q l ( l ( ) ' J l ( ) ~ ( ; : I ~*

I ! ' )H I /HL ' ( ) ( ; i ) ( ) ( ) q ) ( ) l ) 4 1 ~ - ( ) I t ( ) ( ) ' , . ) ( ) ( ) H H ' 7 * " ( ) b ( ) ' 7~ ( ) I ) I H : I : I - ( ) ( ) ( ) ( ) ( ; I I )H I , - I '~'

I ! )H 'J /H ' , I ( )hH,- I ( ) ( ) ( ) l ' , l i )N - ( )q ) ( ) ( f f ) ' ~ ( )H!) '7 ')) ( ) b t l : r 7 ( ) l ) ' J l ( ) , l - ( )1 ) ( ) ( ) '7 '7 ( ) H H H ~

I ! - tH:t /H,4 ( ) h : ) H ( ; ( ) ( ) I H : I H - ( ) 4 ) ( ) ( ) ' 7 3 ()!-)~'7 ~ ' () ,;) It;(-; ( ) ( )14 ( ) ,4 - ( ) l ) l ) ( ) b ( - ; I ) t l ' / g '~° I ! - ) H , I / ~ b () I)'7,I,4 () ()',.!l)I'7 - () 4)()()~',. ) () !-t(';,(* ) l) ,),-I()H () ()1(';'7'7 - () I)I)()tLH l) Ic)~):~'~')

l!-)H;)/Hfi () h'7'7:1 ()()'..),',=),i)~-) -()()()()H9 ()!-)gt-))) i)=)HH9 ()()I'7(;L) -()()l)()'71) ()!-)?b* I!-)HH/H'T () !):I!-),~ () ()IF;I)'7 - ()()()()'7'J, ()!')97 ++ 1) :l!)(Jh () ()l!)'J,(; - ( ) ()()();)U ().!-)(';('; ÷ I ! )H '7 /HH () e l l , l ,1 () I ) I ' ,~H;' - () ( ) ( ) ( ) t ;~ () !~)!-)b '~ ~' () ~)'JH!) q) ()()!..tHH - 4) ()l)()~)t; () !-)73 '~

Y e a r M i l l e l - w h(...at . ) t a l . m

M nl lel W h e a t

h,, h, h,, A' " h,, h. h,, h' '

1!)'7!-l/H() () ,-IH!IH - ( ) ( ) ( )~H:I ().()()()q)('; ().8'7'J ¢''b q) ~fi-)l)'7 - ( ) ( ) ( ) l g b ().q)l)()()'J () HI;N,~,b

I ! - )H( ) /H[ () ,4H(;9 - ( 1 ()()1 I b q),()()()()',.) l) ',..),~1 r''' l) bl-;',.),a l),()()():19 -(),()q)q)() 'T () !-)(;()'~'~

I ! - ) H I / H . () ,-19(),..1 -()()()(;(-;! . . ) () ( l ( ) ( ) l ~ l) ~b '7 ¢'') () ,r')'1'7,..I () ( l l ) : l : tb - ( ) ( ) ( ) q ) l l ' ; l) !-)q):l ¢'+

I ! )~LP/~' , I (),:IH(';',..), - q) ( ) l ) : rTb l) ()()()()G l) ~(-;(-V '¢' () b!..)3H - l) ()()~IHG () ()()()()'..), ql ,u.,?~)~, +

I ! )~ : I /M ,4 () ,-IHI'7 - l) ( ) ( ) ( )~h - () ()(1()(),4 () 'TH'J ~ () bbHH - () ( )( )',..),t;';' - () ()()()()1 l) '7'.)h ~'

l ! ) 8 , - I /Mb () ,-It;tit) - (1 ()()()8!) - () ( )( l( )( )';' () t")l~) ¢'* () ,')'7!91) - () ()()t ;(): l () ()(I()()H I),HS,..[ '

I ! I H b / H G () bHF;H () ()(I()H,I - () ( ) ( ) ( ) IU () H~I ) ¢'~

I ! )H i ' ; /~ 'T () : rT ' /M () l)():r7'7 - ( ) ( ) ( ) ( ) 1 9 () !..)(;!)) '

I ! - )H '7 /~H ( ) h ( i , l H - ( ) ( ) ( ) L ~ I ( ; - ( ) l ) ( ) ( l l : l ()FIt,;',..), +'~ ( )b' , . ) l ,4 ()l)()!+):14 - I I ( ) i ) ( I , . I H ()!-)HI) ~

.... N , ) I ,,,Ii~ r i l l l e a i l i o ,%_,ll~,rilliran I a l b(~', l ~ v e l

b) ,_~l[.,Trl l l lral| i LIt l ~ , l e v e l

water irn~,ati()ns dunng the initial t,w,) years. Thereafter, the m=llet, y ie ld sig n=i~cant lv decreased even at, the Iirst =ncrement tfl'adj.sAR,,.. The efrect ()t' higher levels t)t' adI.~AF~,,,, on m=llet, yield became more pr.nounced aft,er 19,.u,3/84. As expected, wheat, yields under the M - W ro ta ( . . i were afl'ect,ed less than under the R - W n)t~tion. There was not much year t() year v:~riat,,n =n yield de(.'re ments under the R - W mtathm, wh,.'h received considerably lesser s,)di(' irri ~ution water. The number of irrigations t() the millet (.'r,)p was hJrther de creased in the season which received well distributed monsoon rains resulting in the reduct .m ()1' harmful sodic irrigathm efl 'ects. I t may als() be mentioned her(-, that the millet crop failed due to a severe attack (d'ergot ~sease (caused

,.'.q~ M k Ih~,lW,~. AND A :~ II I:.,,~ ~,,

H I L E

'1 U ' ~ , . . , / - . , .

'.", :i: ':; . : : , , ' : , ,_,. 1,, ,,, 1;: ,:, ' .~ . . . . . m ~x~ n n~J

i1 M I L L [ I

W H I A I 14111/1111111

W H [ A I

,, : , . , ' ,,: .... il ,;, ° • , , + i ' ': '

~,; c,

N I l I L I W H I ' A I N I . I I A I I I I t l

WH/" A I

i IOII

11 n~ Io

# ,-

2

I =,

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hy CIm,weps lus~l.rmts) in 1985 and due to a ha=l st i~rm a few (lays heli)re harvesting in 1986.

Fr~)m the data in Fig. 4, c u ~ e s were drawn (he extrapolating s~n~e point,s) t~ shrew I(), 25 and 511% reduct,,m in grain welds ( referred t,~) as Y(. ~, }'(~ ,:,, and Yo., respectively ) during d~fferent years as a I'unetion ~)l'adj SAR ..... It m ev~denL thai maintenance ~d'yleld levels h~gher than 9(1, 75 and 54)% id't,h<me<~htalne<t under C W treatment,, wax possible wit, h irrigal,.m waters having an a(J,j.~AR.,,, ,d' lens l, han ~'3, 2P, and 32, respectively, I'~)r the R,-W r~t,at, i~)n. F~r l,he M - W r()tatl~m, the corresptmdlng aclj SAR.~ values were less than IlL '~B and :IlL re spertwely "this suggests that t, he number (d'years t'~)r which an irrigat..m wat,er, havzngupar twular levelofadj .SAR .... can he usedl '~rmazntaznzngthedeszred levels ~)t'cr~p product~m compared with t h~)se achieved under CW treatment, rouht I)e preclicted. Such t yl:)es of graphs prepared t'~)r varu~us cri~ps and ('r~ffJ rt)tat .ms under clifrerent s~il, climate and leaching c,,)nditions can he useful t'~r making rec<unmendat, i(ms ab<~ut t, he years up t<.~ which it w~ll be p<).~sihle l'(~r lhe farmers t~ live with the prohlem and sustain the desired levels t~l' l)r~ ductu)n. W~)rk ~)n these l~nes is being pursued further

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Balwa, M S , H ira. (.].S arid ~mgh , N 'I" , 198:1 P,,fl'ecl u l ' sodmm and b, 'arbo,l tal ,e i r r i l . ;a t .m wal,ers 41i'l +.;<)churrl accumula l . ior i and ()tl maize arid wheal, vield+~ in N,~r lhern hndia. I,l'rll.+, S<'~, 4 191 - 199

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Eli)we.r, (~ A , l.)gala, (_] and "rlJi.ker, ,J M , 1968 ~ll('l l lJm ha'zard i~l' l lr l[. l ,a[l l l l l wa lers u!., i r lrhJelwed hv leac l img l ' rac lmn and hy prc-,c.pdaf,.m ~r ~.~i~hJl,.~n ol cah 'mm carl:Jonale ,~qbll .~.'I . II)I; 29- 34

Eahm, P M , I!IMI ~qz.nfl . . 'ur, 'e id ' i 'arbonal ,es m i r n g a t . m waler~J ~ml ~,'~ , fig' l 'J ; l -133 Frenhel , H., I!IN,.I Rea~=.;e,..,,~me.ld, oI' wa le r q u a h l v c rde rm ro,l =rr=gal .m In I Shaml:Jerl.,. and ,I

~ha lheve l (B,'dihm.,), ~m l S a h n d v Under I r r i ga l , ,m - Pr~,'esl.=es and Marial.;ernenl Rl:)rml;er, Berhn , pp 143- II-;'7

F'renkel, H and A l p e r o w b ' h , N , 19~,-I T l w el'l'e~'l ~fl' m inera l weal,henr.g ani'l , od s~)hJt . m ~'~)ucer= I ra l . m ~II E,~R -,.SAR relal.,m,,,l'ul:)~)I' a n d and ,~,erm ar id z.me ,~ml~,~ l'r.~rn l~..rael ,I Hml ~'~ , 35 ill; '; - :r;'2

Mwarn i~ l lh ,%_' , It@l() Bl lecl, i l l Lliearl-.irlal,e ~n ,,.il)dllJm ha'za,lrl ~.i' f f r i ga l . ) r l wah-.r A l l ,e rna l lve h~,l mula l lo , l l Sml S~'~ S~w. Am ,I , 4,-I l()'79-l()~,-I

I h.,ler, ,] D. and Fl, h .ade~, ,I D , 19'77 VarlillJ,'.l mcl,'eL~ l'~r evahJal, lr|f.,, l,he ellei ' l , lVe ~;aht,llty and sl) d . ' i l v ~ d i r . l [ ga l .m waler~.~ F'roc [nl ~ah. lu lv ("~ml' "r'exa~.,"l"el.l-i (_]lllV, L,u[l[.~i.l~, Aug 19'71-;, l ip 29(l - ~!'lH

[ - ' ,mnan i l~erur r la , F' N , I~-r;'2 'The ~'heITii~tr,, ' ,Jl'~lJJ'pmerge'd !~,)il~., A,J~.'. AI4r, m , 2.4 '.~I~-!)(; [41"i,p~nde~,, .I l ) , I~)I;H L, ea~'hl l i lZ reqlJlre, rr ier| l ('4)r ex~'hanl4 i -ahle :~()(lllJm ~ ' ,m l ru l £ , , , I A~', S,,, ' A m

[-'r'(~,' , ; t 'J . l -;;+2-(; ,_p(';

,NUaleZ., [) ]_, , I!INI F{,PI;Jtllm be lw , , e r l I..IH, .'lltd +.,,)dlUrrl +ld:.i~lT)ll,~rl r'al i<~ (NA [{ ) a n d al l a l l e r l l a t l v e r rmlh , Jd q~l e,:Jnrrlatlril4 ,_NAh' q~l ,.,q~ll i~r +lrs..llr'i;..ll_.,,e w a t e r ~4ul ,_~,'n NqJ~' Arrl ,J , ,4h .-I1;!J-.4'7.1

II ,~ ,~+lllr|lIV La t J ,~ rah ) ry ,~l+..ll'l, I!-I:~...I Dlal.,q"14+:.+l:.+ l_.lnd [rllprr)'~,. 'emer|l ,,I .~allr le ,LIII<J A l k a h ~+~11,, I_l P.4 D e l d Ar4rn~' H a n d l ~ . + ; l ) , p p 8;I 12(;