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<br />amount dt:lnminc:d uy c.\:actly <br />how much w:lIt:r h.1s dcpll.:tcd <br />frolll Ihe root lone - in pl.1n..' of <br />being s;\tisfit'd th;J[ J. St:t alllOunt <br />of \\";Iter on a sct appli,,'atiull <br />cycle' is tht. Lcst we em Jo. <br /> <br />In oth('r words, irrigJ.ting by <br />[he calcndJ.r h;15 its gross in.ld(', <br />qU3cies. And \\T will bring this <br />point (0 Ihe surfan', rather <br />significantly. hefor... long. <br />First, howt'\'cr, let's look at <br />some c:-.3ll1plcs - providcd by <br />Langk)' and J{abb's report- <br />which documcnt just whal it is <br />wc'rl' dealing with in this "irri- <br />g:lIiol1 'dficiency". Thc)" use a <br />given fidd, gravity irrigated. as <br />Iheir example. The ;J\'aibble <br />moisturc-holding capacity in the <br />root zone is five inches. Delivcry <br />of water lO Ihe field tauls si.\: <br />inches. r\ fi\'e pern'nt loss is <br />amihult'd to distriLution s)'Stem <br />losses and 20 pnccI1t 10 surface <br />runoff. <br />"In oUlward appearancl'S, the <br />two hypolhnical applications :He <br />idl'llIieal, but in Iht' S{'cond <br />example threl' times as much <br />water pl"fl"oLlIes pJ.st the bottom <br />of the' root zone as in the first <br />case:' pointnl out Langley and <br />Habb. "Tht. irrigator nornully <br />has no reau,. means of detl'fmin' <br />ing deep pe~cotation, and thus he <br />feds he is doing equally as good <br />a job of irrigating in the second <br />example as in the first. If Ihe <br />amount of tail waler is used as <br />the critcrion, he is." <br />Again, the attainment of irri. <br />gation efficiency requires con- <br />eerned calcuLnion. We must <br />I...now 1) \\hell to irrig;ue and 2) <br />how much water to apply. <br />A good case in point is this <br />study conduned by the Bureau <br />of ){eclJmarion on 35 acres of <br />sugJ.r bcet~ near Grand Junction, <br />Colo. Eaeh bar represents one <br />irrig::ltion. The left bar represents <br />the depleted soil moisture at the <br />time of irrigation. The right bar <br />represents thc IOLll wa.ter deli\'. <br />ered - the amount below the <br />line being losses (with scpar.1tion <br />made as to what los~s \\ere <br />attributed (0). <br /> <br />(colll;llllcd 011 page IS) <br /> <br />.n <br /> <br />~~'."~r'~~;~~~~I'~' - ~j- <br />.- ~ <br />' t=....n.-'_~~........._ <br />=;)~._..._...._- rn 1 <br />i ~~~~~::~~:~~.._- T-~-n~~ ~ <br />r-' ---rl1]~ I' ~~~If:~ <br />,') j- rit-I~iol [I~ IUI~I~b <br />':r-I j ~ i I IlDJJ, ,,_.' ~ <br />I I ~ ~. , !:: ~ :: ~ ~ <br />'r T tt~. 1,1- Lf--[-l <br />,- I. ~. I ~ I~I~ <br />, I , r~ i I <br />. ,- - - - -:1 -~ <br />r- <br />, <br />:1 <br /> <br />.:~ <br />. <br /> <br />I <br /> <br />.I <br /> <br />! SUGAR tEtlS <br />I CRA\'lD JUNCIlON. COLORADO <br />IL""-"--' .-." <br /> <br />_. .."....n _eOl' ..,.,~... ..,..~." <br /> <br />. <br />, <br />'I <br /> <br />.....,... <br /> <br />"...... <br /> <br />... <br /> <br />- <br /> <br />O' <br /> <br />DISPOSITION 0' WAlt" '"'''''1,.1[0 10 SUCIIR [l[tTf> <br /> <br />. <br />. <br /> -' <br /> t <br /> , <br />. I <br /> I <br /> . <br /> - <br /> ~ <br /> f-J <br /> <br />-... ....... _..~ <br /> <br />---..--- <br /> <br />$lJ(;U IUI$' GUNO JU"CfION (01-0"'00 <br />C.._......V.. <br /> <br />C\I <br /> <br />~~ I <br />I[I~ ~ = ~Il. . <br />'--_1'-' j <br />lL_LU JJ <br /> <br />M <br />~ <br /> <br />_.... -... <br /> <br />I <br /> <br />-..---...-- <br /> <br />s.vc;U IlU$. GhNO JUN'"0" (o..OhOO <br />eIWffKl,.... CONSVMPT'Vl USf AND 'An", "'IRlOAT'ON ffI"IC'tNC'f$, <br />