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<br />'" <br />t,,,, <br />!'--' <br />Q <br /> <br />During the first irrigation of annual crops and of <br />perennial crops for stand establishment (e.g. alfalfa), <br />many farmers in the Lower Gunnison apply a large amount <br />of water to "black over" the soil so that seeds.have <br />adequate moisture for germination and establishment. The <br />elimination of this practice would substantially reduce <br />deep percolation (amounts during this irrigation are <br />twice as much as the average amount during all other <br />irrigations). However, alternatives are needed which <br />when accepted by the landowner, will ensure stand <br />establishment. Deep percolation losses during this <br />first irrigation, are greater than amounts found during <br />any other single irrigation. This is directly related to <br />a high infiltration rate and downward movement of water <br />which greatly exceeds lateral movement. <br /> <br />4) 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 budgets <br />Table 2 summarizes the seasonal data, and represents the <br />total flows on and off the field, total deep percolation and <br />ET. The precipitation and ETa data also shown here are <br />measured from planting date to harvest date. The amounts in <br />these columns vary for each site because of the length of <br />record for different crops. Some of the variations are due <br />in part to the different crops and climatic variations at <br />each location. <br /> <br />D) trends <br />Extreme variation best describes the current irrigation <br />systems and their use of irrigation water application being <br />used on these sis sites. All sites do not currently have <br />contracts in effect but in the future either these sites or <br />at least other fields controlled by these operator/owners <br />should have contracts. This is significant with regards to <br />trend because producers in the LGCU are indicating the <br />desire to install improved irrigation systems which will <br />provide the means for improved irrigation of a variety of <br />crops. Also, the producer can become better informed <br />regarding the application of irrigation water. <br />However, these intents do not entirely replace the deep <br />feelings instilled when the water first flowed in group <br />delivery canals...so long as the water shall flow through <br />these fields, it shall flow across them. The continuous <br />flow of inexpensive water and the "use it or lose it <br />attitude" are ever-present as we implement salinity control <br />in the LGCU project area. <br /> <br />1.3 <br />