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<br /> Table 2 ~ \cNy- <br /> Colorado River Salinity Control Project ' ~ <br />rv 1995 crops Monitored /' c:: <br />("J ~ <br />CO Site I....i". Field N""",r Vol.of Vol.of Infiltrated ClJTLIlative ",:Appl i. Soil <br />~ 10 Sy,. Size of InfLow Outflow Depth Precip. ere D.P. Eft. Type <br /> (#) Type Crops (At.) l..r19. (In.) (In.) (In.) (In.) (In.) (In.) on <br /> 21 PGS Al fal fa 54 6 45.3 7.8 37.5 2.5 25.2 11.5 57 Fr <br /> 32 CDS Fall Grain 23 2 11.4 7.7 3.7 0.4 2.2 0.0 32 Hk <br /> 57 PGS Corn 43 6 34.3 10.6 23.7 2.5 23.1 4.5 56 Rt <br /> 62 EDS Fall Grain 22 3 38.4 27.8 10.6 2.3 8.9 2.9 20 Rt <br /> 63 COO Fall Grain 29 4 71.6 30.2 41.4 2.3 10.5 27.3 20 Rf <br /> 64 CDS FaLL Grain 19 4 52.4 25.3 27.1 2.4 10.9 14.4 24 Re <br /> 65 CDS Fall Grain 37 5 39.1 8.3 30.8 2.4 11.1 18.0 33 Hk <br /> 66 POP Fall Grain 11 5 44.8 14.7 30.1 2.5 11.2 16.8 30 at <br /> Average 3D 4 42.2 16.6 25.6 12.3 ,11.9 32 <br /> Surface Irrigation System Types <br /> <br />PGS -- Pipeline to Gated Pipe--Surge CDS -- Cone. Ditch to Siphon Tubes <br />PCP - Pipel fne to Gated Pipe GPP - Gated Pipe <br />EDS -- Earthen Ditch to Siphon Tubes COG -- Concrete Ditch to Gated Pipe <br />Vol~ of (nflow = Total depth in inches delivered to the entire field <br />Vol. of Outflow= TotaL depth in inches leaving the field 8S surface runoff <br />Infiltrated Depth= Volume of inflow minus volume of outflow, or the average depth of water entering the soil <br />Precip.= The measured precipitation from planting date to harvest date <br />ETa= The total actual evapo-transpiration from planting date to harvest dete <br />ETa= Etp x crop coef. x adj. factor for stress or excessive moisture <br />D.P.= Deep percolation in average inches over the entire field <br />D.P.~ Infiltrated depth - sofl water deficit at time of irrigation <br />Irrigation Eff.= (Vol. of inflow - vol. of outflow - D.P./vol. of inflow x 100 <br /> <br />summary Of Field Evaluations <br /> <br />The following is a brief summary of the 1995 monitoring field <br />evaluations: <br /> <br />The average irrigation efficiency of 32% for the monitored sites <br />approximates the 33% goal set by the USDA in its Planning Document <br />under Alternative Plan 4B. ' <br /> <br />In 1995, about one-quarter of the farmers with monitoring sites <br />practiced a high degree of irrigation water management (IWM). <br /> <br />Poor irrigation efficiencies at some sites are due to irrigation <br />before soil moisture deficit reaches 50% of field capacity. All of <br />the monitored surface irrigation systems are capable of irrigating <br />at 50% or greater efficiency with proper management. We continue <br />working with these individuals to help them improve their <br />irrigation water management, and determine the causes of <br />inefficient irrigation. <br /> <br />During pre-irrigation of annual crops and first irrigation of <br />perennial crops for stand establishment (e.g. alfalfa), many <br />farmers in the Grand Valley apply a large amount of water to "black <br />over" the soil so that seeds have adequate moisture for germination <br />and establishment. The elimination of this practice would reduce <br />deep percolation substantially. However, farmer-accepted <br /> <br />7 <br />