Laserfiche WebLink
<br />~ <br />",,., <br />~ <br />~ <br /> <br />8. Several years of monitoring data from improved surface and <br />sprinkler irrigated sites indicate that the overall average <br />deep percolation (surface+sprinkler) for the Grand Valley <br />is 15.8 acre inches per acre. . <br /> <br />9. Deep percolation from .surface sites could be reduced by as <br />much as.30 to 50% with use of surge. irrigation techniques. <br />When deep percolation data from the 20 surface irrigated <br />sites are separated by conventional (12 sites) and surge (8 <br />sites) 'systems there was a reduction of about 14.2 inches <br />of deep percolation per acre from surge sites in 1993 <br />. (Table 2). In 1992, the reduction was abo~t 10.5 inches, 6 <br />inches in 1991. An even greater savings of.50 to 80% could <br />be realized by converting to sprinklers. The,use of <br />sprinklers is limited by. the cost of pressurizing the <br />system and the elimination of corn. as a crop alternative. <br /> <br />side-by-side comparison of surge sites with conventional <br />sites during 1991, 1992 and 1993 showed that surge could <br />reduce total water application, tailwater runoff and. deep <br />percolation by as much as 20 to 30%. <br /> <br />. ~! <br /> <br />-io. <br /> <br />11. Where improved irrigation systems have been 'installed, <br />the deep percolation losses can be'reduced substantially <br />by proper management of individual irrigation events. <br />Reducing set time (number of hours per set). and waiting <br />longer between irrigations (irrigation sCheduling) would <br />reduce deep percolation significantly, and also' increase <br />irrigation efficiency. <br /> <br />c. Summary Of. Water Budget, Deep Percolation And Application <br />Efficiency . <br /> <br />water. Budget: ~he results of the 1993 irrigation monitoring <br />evaluations from the 22 sites are presented in individual site <br />sumiilaries located in . Appendix D. All irrigation .events, including' <br />pre-irrigation events, were monitored for all sites. Table 2 <br />summarizes .the seasonal data obtained from the 22 irrigation <br />monitoring sites and also shows the breakdown of data by crops and <br />irrigation systems. The data in Table 2 represents the total flows <br />on and off the field, total deep percolation and ET for all <br />irrigations during the 1993 irrigation season. The information on <br />Table 2 has been extracted from individual irrigation summaries <br />provided in Appendix D. <br /> <br />The information on intake family, slope, soil, acreage etc. shown <br />on individual summaries in Appendix B was obtained from SCS files. <br />other data was measured in the field or calculated. Data collected <br />is explained in detail under "Measurement and Calculation"- section <br />of Appendixc. The advance time shown in individual summaries is <br />the time taken for water to advance from the top (inflow measuring <br />point) to the bottom of the field where the outflow weir was <br />14 <br /> <br />:.:'~-}~ <br />.,...--,:~ <br /> <br />I <br /> <br />I <br /> <br />'-('ej <br />......... <br />. '~., <br /> <br />I <br />