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<br />~{., <br /> <br />co <br />,('t) <br />..-l <br /> <br />'-,,~' <br /> <br />Site 27 was in co...n in 1989 and beans in 1990. The...e we...e seven <br />i......igations du...ing the season. A total of about 79 inches of wate... <br />was app lied to the fie I d and about 42 inches was lost as deep <br />pe...colation <Table 2). Of the 42 inches deep pe"'Golated, <br />app...oximately 3 inches was acceptable deep pe...colation fo... sal inity <br />cont...ol <Table 6). The ...emaining 39 inches was e:<cess deep <br />pe...colation that the plants could not use. In 1989, 84 inches of <br />wate... was appl ied of which 50 inches was lost as deep pe...colation. <br />The ope...ato... tends to ove... i......igate no matte... what c...op is being <br />managed. I......igation efficiencies we...e in the 20% ...ange fo... both <br />yea...s. <br /> <br />In cont...ast, site 48 is a bette... managed field even though it did not <br />have an automated i...... i gat i on system like gated pipe whe...e i...... i gat i on <br />flow can be adjusted. This site was doubled c...opped to beans <br />following small g...ain. App...oximately 60% of deep pe...colation losses <br />occu......ed du...ing the fi...st i......igation (Table 7). As a ...esult, the <br />application efficiency fo... the fi...st i......igation was about 21% which <br />...esulted in ove...al I efficiency of about 35% fo... the site (Appendix B). <br />Wate... appl ication at this site was almost half of that appl ied at site <br />27, about 42 inches ve...sus 79 inches, ...espectively. <br /> <br />Onions: Only one site with 17 ac...es was monito...ed. Twenty two <br />i......igation events we...e ...eco...ded. A total of 88 inches of wate... was <br />appl ied to the field of which about 39 inches was lost as deep <br />pe...colation (Table 2). Acceptable deep pe...colation is about 3 inches <br />(Tab I e 6) fo... sal in i ty cont...o I, the...efo...e 36 i nch.,s was excess deep <br />pe...colation that the plants could not use. <br /> <br />About 34% of deep pe...colation occu......ed du...ing the second i......igation. <br />The...e was no deep pe...colation fo... six i......igation events du...ing the <br />ea...ly pa...t of the season (Appendix B). Onions need f...equent sho...t <br />i......igation du...ing bulb development stage. Du...ing peak g...owing pe...iod, <br />the ope...ato... i......igated eve...y fou... to five days with about 3 gallons <br />pe... minute fo... about 24 hou...s. Some i......igation wate... management is <br />being followed but is not adequate to cont...ol deep pe...colation. Su...ge <br />may help in this situation. <br /> <br />Su...ae and Conventional I......iaation Compa...ison: <br /> <br />Twenty fou... su...ge i......igation events we...e monito...ed on about 40.2 <br />ac...es; 23 conventional i......igation events on 31.2 ac...es we...e also <br />monito...ed. Within the same field, su...ge and conventional sites we...e <br />located side by side (sepa...ate ac...eages) fo... compa...ison. Compa...ison <br />of su...ge and conventional i......igations in the same field with simila... <br />so i Is i nd i cated that with the use of su...ge systems the...e cou I d be <br />savings in wate... appl ication; tai Iwate... and deep pe...colation could <br />also be ...educed. <br /> <br />28 <br />