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<br />::.\~?;) <br /> <br />f') <br />co <br />t..:, <br />o <br /> <br />.< <br /> <br />Observations and Discussion <br /> <br />It was observed that surge irrigation perfonned best on row crops where the furrows were in good <br />condition, Irrigation water applied via corrugations, as often used in pasture and hay land fields, crossed <br />over into other conllgations, making it impossible to accurately monitor the inigation flow, Conuga- <br />tions often breakdown because of heavy wheel impact during the harvesting process, Therefore, it is <br />important that fields be re-marked after each hay cutting, It was also observed that first irrigations on <br />newly planted fields required more set adjustments and follow up procedures under surge, However, <br />some operators feel that surge does not adequately wet the soil so as to germinate seed, Theu' preference <br />is to use conventional irrigation methods to accomplish seed germination and then revert to the use of <br />surge once the crop has been established, Our field uials have indicated that surge advances and time <br />of advance cycles may be adjusted to achieve the desu'ed amount of soil soaking needed for seed <br />germination, <br /> <br />A major misconception by producers is that surge will solve all their uTigation problems, <br />therefore, they have used the surge system on their poorest fields with difficult cross slopes, Producers <br />and planners need to recognize surge is only a management tool, it cannot be used to overcome field <br />constraints such as land leveling needs, slope variations, gravelly soil, poor furrow and conugation <br />conditions or unusually long runs, etc, Some participants have indicated that surge systems can operate <br />by themselves, thus, the participants do not spend enough time in the field during the irrigation sets. This <br />creates over-watering or under-watering situations even though surge should reduce the amount of <br />water used and time spent in the field, Initially it has been found that the farmer/rancher may need to <br />spend more time with the surge unit until becoming familiar with the different programs and what will <br />work best for a particular field, The surge controller is much like a computer in that, if it is incorrectly <br />progranuned, the individuals wilinot be able to achieve their objectives, There were instances where <br />surge irrigation showed under-irrigation. Such were the results on farm D2 and D6 in Table 2 and M2, <br />M4, and M6 in Table 4 where surge litigation shows negative deep percolation, indicating a deficit <br />irrigation. The above could be the result of improper monitOling, or it may have been due to the <br />assumption of a higher soil moisture deficit Estimated soil moisture deficit was established, in part, <br />on the basis of SCS infonnation or water holding capacity. Soil moisture was monitored by the use <br />of soil probes, gypsum blocks, hand-feel method and aquaterinstruments, Soil moisture depletion was <br />monitored by tracking the daily Evapotranspiration (ET) of the various crops being grown. This was <br />accomplished by the use of a weather station accessible by computers, The weather data obtained was <br />then used to compare soil moisture conditions with observed field soil moisture estimates as well as <br />being used for inigation scheduling, In addition, agricultural producers and the general public could <br />obtain ET information waugh the Montrose and Delta newspapers, <br />Lower Gunnison Surge Demonstration Project. Page 11 <br />