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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 <br />values 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 <br />that the current use is irrigated pasture. Pastures on shallow soil have a lower production value <br />and 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 <br />pasture recovery periods before grazing with allowance for a 4 -5 inch stubble height of <br />vegetation remaining at the end of the growing season (SCS 1985). Observations during 1999 <br />indicate that the trend is to graze early, continuously during the growing season, and late for a <br />number 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. <br />These lands normally occur as the remnant sagebrush type or as disturbed areas associated <br />with farmsteads or facilities. In these cases, the operator has chosen to apply irrigation water <br />on seeded pasture species even though the site potential is low. In some cases, the sites are <br />so shallow, that tillage and seeding are not feasible and continued application of irrigation <br />water has allowed for volunteering of species normally found in the irrigated pasture type. <br />These shallow, sites have a lower production potential than the deeper sites, but it is much <br />higher than if left in the dry remnant sagebrush state. Within the irrigated pasture type are <br />Revised September 2010 (PR 06) 2.04.10 -58 <br />