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<br />',-1 <br />t- <br />(1') <br />, ..-l <br /> <br />c.: <br /> <br />Water Budllet: <br /> <br />Table 2 summari2es the seasonal data obtained from the 25 irrigation <br />monitoring sites and also shows the breakdown of data by crops and <br />irrigation systems. The data on Table 2 represent the total flows on <br />and off the field for all irrigations during the 1990 irrigation <br />season. The information on Table 2 has been extracted from individual <br />irrigation summaries provided in Appendix A. <br /> <br />During the irrigation season, all irrigation events, including pre- <br />irrigation events were monitored for all sites with the exception of <br />sites 45 and 46 (comparison sites). At these sites, the first (fal I <br />irrigation) was not monitored since it was not known at that time <br />whether the Bureau of Reclamation funding would go through. The sites <br />were establ ished in spring. <br /> <br />The information on intake fami Iy, slope, soi I, acreage etc. shown on <br />individual summaries in Appendix B was obtained from SCS fi les. Other <br />data were measured in the field or calculated. Data collected is <br />explained in detai I under "Measurement and Calculation" section. <br />The advance time shown in individual summaries is the time taken for <br />water to advance from the top (inflow measuring point) to the bottom <br />of the field where the outflow weir was located. <br /> <br />The precipitation and ETa data shown on Table 2 are measured from <br />planting date to harvest date. The amounts in these columns vary for <br />each site because of the length of record for different crops. Some <br />of the variations are due in part to the different crops and cl imatic <br />variations at each location. Among perennial crops, ETa data vary for <br />the same crop at different sites (e.g. sites 30 and 33) because of <br />differences in crop cover and maturity. Stress factors due to soi I <br />moisture deficit also affect ETa values (refer to page 11 for ETa <br />definition) for both annual and perennial crops. <br /> <br />Under individual irrigation summaries, the ETa and precipitation data <br />are shown in the tables as a value for each irrigation event. The <br />value shown is the calculated ET for the particular crop from the time <br />of previous irrigation event; or for the first irrigation event it is <br />ET~ from the beginning of plant growth to the date of the irrigation <br />event. <br /> <br />The soil moisture deficit before irrigation was determined from the <br />dai Iy water budget computer program (refer to page 11 for definition). <br />AI I sites were probed before the start of the irrigation season to <br />estimate soi I moisture deficit before irrigation. If the infi Itrated <br />depth for a particular irrigation event exceeded the soi I moisture <br />deficit before irrigation, then the sol I profi Ie is assumed to be full <br />and there is no soil moisture deficit after irrigation. However, any <br />excess beyond what is needed to fill up the so i I prof i lei s cons i dered <br />to be deep percolation. <br /> <br />14 <br />