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5.2 Irrigated Pasture Type - 1987 (IP) The irrigated pasture represents lands intermediate <br />between the remnant sagebrush types (generally a former pinyon -juniper woodland site) and <br />the more intensively managed irrigated hayland type. Depending on the objectives of the land <br />manager or the level of management applied, lands that may be adapted to hayland production <br />or lands that are only slightly more adapted than the sagebrush type for pasture production are <br />included. <br />As anticipated, total vegetative cover was high at 72 percent (Table 2.04.10-5) with litter <br />averaging 23 percent, for an average total ground cover of 95 percent. Bare ground averaged <br />only five percent. Total vegetation and litter combined would most likely have approached 100 <br />percent if not for the effects of grazing pressure in the pastures. Consistent with the <br />management and use of these lands, perennial graminoids dominated at 43 percent of the <br />vegetative cover while perennial forbs accounted for nearly all of the remaining vegetative <br />cover (29 percent). The only other morphological class represented was annual forbs at a low <br />0.3 percent cover. Of all species encountered in cover sampling, Kentucky bluegrass (Poa <br />pratensis) had the highest cover and second highest frequency at 21 percent and 87 percent, <br />respectively. Buckhorn plantain followed closely with the second highest cover (14 percent) <br />and highest frequency (93 percent). Other important species were orchardgrass (Dactylis <br />lomerata at 9 percent cover (67 percent frequency), white Dutch clover (Trifolium repens) at <br />9 percent cover (80 percent frequency), timothy (Phleum pratense) at 3 percent cover (60 <br />percent frequency), dandelion (Taraxacum officinale) at 3 percent cover (53 percent frequency) <br />and red clover (Trifolium pratense) at 2 percent cover (47 percent frequency). A summary of <br />the individual transect data is presented in Attachment 2.04.10-6 (formerly Peabody 10-2 <br />(Table 2-1)). Total annual production for the type was estimated at 2,822.6 pounds/acre (Table <br />2.04.10-6). Indicative of the highly variable nature of the type, production estimates from the <br />sample plots ranged from 230 pounds/acre to 8,994 pounds/acre. This large variation was due <br />to the amount and timing of irrigation water application, the amount of supplemental water <br />received which was incidental to the regularly applied amount, and the intensity and duration of <br />grazing prior to the placement of range cages. As an example, sample 2 was dominated by <br />Kentucky bluegrass and buckhorn plantain (Attachment 2.04.10-6, formerly Peabody Appendix <br />10-2, Table 2-2)). Both require supplemental water to be present and survive in the and Nucla <br />area and both are dominant in irrigated pasture in the study area. <br />February 2015 (TR -66) 2.04.10-29 <br />