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Total annual production for the type was estimated at 4,153 pounds/acre. Woody stem density <br />was zero in this type. A total of 64 species were found to occur in the type, with 21 of those <br />species encountered in the cover sampling. Only 15 of these species had relative cover values <br />of 1 percent or greater. Of these 15 species, 8 were graminoids and 7 were forbs. <br />Irrigated pasture occurs on soil map units 98A, 98C, 98D, 98E and 98F and 98G. Soil ranges <br />from deep to shallow. Moderately deep to deep irrigated pastures have a potential to become <br />irrigated haylands. Some operators have chosen to let hayland areas degrade over time so that <br />the current use is irrigated pasture. Pastures on shallow soil have a lower production value and <br />are irrigated solely due to the fact that they are down slope from an irrigation ditch. <br />The 1987 conclusions are restated here as they have the same application and results as <br />those found in 1999. The general stocking rate for the irrigated pasture is approximately 1.2 <br />AUM's/acre at a 70 percent utilization rate. Since the production on these pastures can be <br />sustained by irrigation, this stocking rate should apply during the majority of the growing <br />season. Ideally, the forage should achieve a 4-5 inch height in the spring and between pasture <br />recovery periods before grazing with allowance for a 4-5 inch stubble height of vegetation <br />remaining at the end of the growing season (SCS 1985). Observations during 1999 indicate <br />that the trend is to graze early, continuously during the growing season, and late for a number <br />of the operators. <br />Many factors contribute to the composition, utility and appearance of the irrigated pasture type. <br />Soils vary from deep sandy loams to shallow sandy loams with a few rock outcrops (see <br />Section 2.04.9, Soils Resource Information). The moderately deep to deep soils could be <br />placed in hay production, however the various operators' management objectives dictate a use <br />of these lands for irrigated pasture. At the other extreme, are the areas of shallow soils. These <br />lands normally occur as the remnant sagebrush type or as disturbed areas associated with <br />farmsteads or facilities. In these cases, the operator has chosen to apply irrigation water on <br />seeded pasture species even though the site potential is low. In some cases, the sites are so <br />shallow, that tillage and seeding are not feasible and continued application of irrigation water <br />has allowed for volunteering of species normally found in the irrigated pasture type. These <br />shallow, sites have a lower production potential than the deeper sites, but it is much higher <br />than if left in the dry remnant sagebrush state. Within the irrigated pasture type are small <br />localized areas that receive only limited amounts of supplemental irrigation water because of <br />February 2015 (TR -66) 2.04.10-57 <br />