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<br />
<br />.~" "
<br />I~}
<br />.,
<br />, .'~
<br />, ,
<br />,cc
<br />/,.~ .
<br />when tllC ClOP!!'. hnrT1iltllrc i1mJ Ilw C;UlyOVCl soil nlOistUlC IS ildequ~lo t~
<br />f\10cl Elp, 11121 has no provisions IOf c.Hlymg over e~ccsS 5011 mOlsl~l~
<br />IHinl one fllOlllh 1'\ annlhcl. Cnrnpiu'SOIl 01 5MB v(llues in rnule 3 s~p
<br />thai illl irriOillOf~ Irrigation rrequency C<ln irr,pacl IWn; r:ore lreQu~?
<br />ifllUillion results In inCrlJilr.ctJ 5011 SUdil(;P llvnpofill,on and hIGher IWR:.~
<br />
<br />
<br />c,c,'jr
<br />
<br />11I'1I1
<br />
<br />Illlll{jAIIIJN ^,~l} lllIAINAf;1 -",Y"[I_MS
<br />
<br />,
<br />
<br />Table J. Averllgo Annual IrriUilllon Willer lloQui,emr.nl(mm}
<br />
<br />Crop
<br />
<br />Crop 5MB TR21-
<br />Distel. Fiu.'tJ 5MB 5MB
<br />bUlion Interval MAD F1Kcd
<br />t%l 11121 Inig. Irdg. IIHorval
<br />1(1.0 612 " 01<19.3 4,193 163.1
<br />22.5 1\45.3 372.9 305.6 62.4
<br />22.5 402.3 3056 260.9 96.7
<br />12.0 3198 263,0 270.) 36.8
<br />16,0 537.7 509.5 .1GO 5 28.2
<br />H 270.3 470.4 ,182,3 .200,'
<br />6.0 231 1 731 1 2~2.~ .61.8
<br />1 0 50<12 50,12 398.3 105.9
<br /> <1<196 3800 3<15.7 69.6
<br />
<br />Allalfa
<br />
<br />reed Corn
<br />
<br />Silllge
<br />
<br />Bc:ans
<br />
<br />I1ce1S
<br />
<br />Onions
<br />
<br />Small
<br />Gram
<br />
<br />Pasture
<br />
<br />Wid. Avg
<br />
<br />
<br />-
<br />-
<br />
<br />C"-
<br />-
<br />
<br />AI'I'I.lCANTS ^Nll OIl)I'(,-n*$
<br />
<br />10'"
<br />
<br />--
<br />-
<br />
<br />2c
<br />
<br />Tl1UIO <1.12 (SCS.19741, i) tilble or t1f~~ign otrlcier\ci('~grilded
<br />hOfrlers, WtlS replcscnt<llivt! o! <Je\l!ill c!lici"nci~~ on ;Ill S\lrlilce
<br />Irrigalcd fif'lds, Including fllrrows.
<br />1IlC htlsic intilke fnlO of soils Clln be dermminell ,,~inV SlJdtlce SOl!
<br />leKlulc.
<br />For 811 iHigillion lhe lime 01 tlpplica1ion was B hOllrs llnd lhe nl'!t
<br />depth of apf)licalion WilS 3 inches.
<br />ricld lengths w('re 1,300 feet nnd lypic.,llim... 01 nllv"nr;c WilS two
<br />hours.
<br />Furrow spocmg was'} 5 Icet .lOd all irrig,lIiorH welc nltl'rf1al"
<br />IUHOW.
<br />nepresrmtlllivc slopcs for use in SCS design efluat;ons ilnd I<lhles
<br />WCIO dcrived by nveragillg slop!!s mOi)sured Irom USGS flllil(\ranglns
<br />maps which had comoul imefvnls 01 10 leet.
<br />For cylinder illtakn lilmllil~S of 1.5, 1.0, Illlt! 0.'1, r"rrow flow fllt"S
<br />rtlnoed Irom 30 In 50 opm. 25 to 45 Opm, Iln" 15 to 30 \'If''''
<br />respeClively.
<br />
<br />3c
<br />
<br />5c
<br />
<br />6,
<br />
<br />.,To estimatc nn nllicicncy Irom Tl1hle -1.12 ISCS. 197,11. Ille rnginef'r m"q
<br />; know Ilel depth 01 l1pplicntion, licld slope and tl11sic soli inlnke 'ilmily. TIm
<br />~ basic 5011 inlnke 1amily was df!fived u~ino Figure 111.2 (Oilllf1lJf!f, ('1.01. 19791.
<br />: B plot of cylindor Intako lamilies VCHSU~ sutlllCO soil to"IuIO. For (loch Illlm.
<br />'l.Thornton dCHHmlnod Iho dlstriUUllon 01 sollfnlnkll lamlll('~ uslno SCS SOil
<br />,Survey maps and dala. Using avcrage Ileld slope, a net d('plh 01 applicallnn
<br />. of 3 inches and T,lule 4.12, an cllidency WIlS determined lor Pilch l"miTy
<br />The appliClltion elficienr:y 10f thu ftlfm W,'S calc,,1M'.'d ilS Ih" w('iUh"d"
<br />~. ilveraue of the efficiencies 101 ;]11 soillnlllk!l familil!s. NC&WWWanalyled
<br />; Thornton dnla find deleUnif1f'd tIle disoiuutiOIl 01 ThornlOn's aflpHclltion
<br />~: elliciencies 101 sudacc irrigalr~d lIe Ids 10 bf! ,l~ shown in Tjl!lle ,1
<br />....
<br />
<br />'1 ',:1)
<br />'i'.q..
<br />hritllltion Applicillion Ellicienr;y. SurfnCtl nUf\orl t. Deep Pcrcol:ltioll J;>;'
<br />" I ~lm
<br />,...,
<br />Thl) pro<::mlures used \U rtnt.~rll"flc Iw,tortC applicnt;on el!,cio!1CY
<br />swlilCt~ r\lnol! and deep pcrcol"tlon losses we.re very dllrclcn\. ThOr"t~t'
<br />estinll}\cS were dfJlcrmifled usmg SCS SOli SUlvnys antI SCS dcsl~
<br />hnndbouks 101 hOfder nnd IUHOW irrilFllion ISCS. 197<1. & SCS, 19B.~.J
<br />NCe.WWW's valuf:s werc hascd on !Ield invcslIOiHion, me(lsufcd CI!I,C,r~~,
<br />des and il walel ualanCIJ analySIS NClNJWW's approach Ims seldo~ p'~cn
<br />uSl)d In prevIous water If;)nslers heciJusn 01 Ill!) COSI Involved. ,'i'~."
<br />
<br />111 utlllllllU the SCS (lCSIU" r",IIl"iJls I{lf IHJrucr and II/rrow l!,igililO .
<br />to delcrmUll! el!iciencles. swfaco IUfloll (lnu UllCp p(!fCOlall~n?" S~,~..!~;
<br />irriuatf:d f,elds, Thornton rl1<lde sevr~ri11 ilSSU!I1111H.HlS. Includml]. ,.:(
<br />, ~..1(,I,
<br />Furrow iUlnation is more tdhcienl tl1nn !:lIDded horder. 'il-;:
<br />1. u .~;+
<br />".;\"
<br />"f;f
<br />~.
<br />, ,~, ~
<br />
<br />Table~. Distribution 01 Thornton's Irri!Jlltion Application EHiciencir.s
<br />
<br />Irr.EI1.I%1
<br />
<br /><40 40.45 45.50 50.55 55.60 r.065 65.70
<br />o 17 ,1 2 15 <18 1<1
<br />
<br />,'% 01 Farms
<br />
<br />,c
<br />
<br />Thornlon l'stim::llcu Ill{' flerCentage 01 farm heilo!J"tf' drliverics lost
<br />,10 II/no If DIlU decp perCOlallOn llsinn lhe SCS deSlon rnnnunl for furrows
<br />lSCS, 19B,I). Using the apfllicilble nssumpllons listet! i1hovo lor d1l11l inpllt
<br />l' Ilnd eq(!,1tiol1s from CI1,lpl,~r 4 rOf uradI'd l\lffOWS. Tloorl1ton cnlcul,llf~rJ
<br />,'.',. IUf/oW !low rillC. advilllce time, 1}ross depth i1pphcd. Ilvern~]\l oPPOrtllnlty
<br />. I lime, avera!)o cumuliltlve rrlwk'J i'llld runol! deplh, (See SCS. 198.1, rmd
<br />ieQuRlions 5.1 tlnot/uh 5.11). NCl.WWW analYlf'd Thorl1too's <lala and
<br />',determined the dIstribution of Thornron's sur/ace funol! Ilnd del'p pefcola.
<br />,'tion losses as 11 percent 01 tOla! water ilpplied 10 the surlace Irrigated fi"lrls.
<br />. The rnsulls arc summallled in Tilbll' 5, line! show 'nf f'~llmfllo lhal on 18%
<br />
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