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<br />. <br /> <br />o <br />I'" <br /> <br />, . <br />,-" <br /> <br />~ <br /> <br /><.:7:.\ <br /> <br />cooperators were given either an in-line surge valve. a gated pipe "T" shaped surge <br />valve or a ported ditch surge gate. together with an appropriate controller, One <br />unit was made available for each farmer selected. After a short workshop on the <br />use of the surge valves, the cooperators installed them in their irrigation systems <br />and began to use them for their first irrigations, The Cooperative Extension team <br />was able to study 1 49 conventional and surge irrigations throughout the 1 993 <br />irrigation season, Both inflow and outflow of a single furrow were measured with <br />v-notch furrow flumes and automated data gathering devices. A furrow that had <br />no wheel traffic upon it was selected for the evaluation. This presented conditions <br />conducive to the greatest amount of deep percolation and least runoff of the <br />applied water (a worst-case scenario). Forty-one of the irrigations produced <br />useable data. The remainder were rendered unusable due to furrow washouts and <br />crossovers and occasional malfunctions of the data gathering equipment. Some of <br />the flumes became silted making the data questionable. <br /> <br />Total acres included 32 acres conventionally irrigated and 28 acres irrigated by <br />surge methods during the 1993 irrigation season. All fields are not listed on the <br />attached tables due to data collection problems. <br /> <br />The SCS monitoring team monitored two of the fields. and provided total inflow <br />and outflow water measurements from the fields. Evapotranspiration values for the <br />crops and software for evaluating data were also provided by the monitoring team. <br /> <br />EVALUATION: <br /> <br />Irrigation events were recorded on 149 occasions throughout the 1993 crop year <br />with 140 events yielding useable information. The 2 primary causes of unusable <br />data include water breaking out of the furrows and the "v" notch flumes silting up. <br />In addition, birds pulled the string from the flumes and small animals (skunks and <br />raccoons) disturbed the floats on occasion. The two fields monitored by SCS <br />provided the most reliable data and projections will be made from this information. <br />These fields are identified as M51 and M55 on the data sheet in the farm number <br />column included with this report. The other farm numbers are those where <br />individual furrow flows were measured. See attached data sheets. <br /> <br />Note that some farms have negative numbers in the deep percolation column. This <br />indicates deficit irrigation (the water used by the crop was not replaced totally by <br />the irrigation water) and it increases the efficiency to an unrealistic number. Some <br />fields are believed to be sub-irrigated with water from a higher elevation. The <br />cause of the deficit irrigations on the other fields is unknown. Perhaps the method <br />of calculating evapotranspiration may need to be refined, and some data collection <br />error may have occurred. A crop planted earlier or later than the reference crop, <br />used for evapotranspiration calculations, will use water differently than the <br />reference crop. <br /> <br />3 <br />