Laserfiche WebLink
The potential productivity for the Shavano and Persayo soils was <br /> determined by methods and procedures outlined in the SCS National Range <br /> Handbook (1976) and on Form SCS-Range-417(Rev. ) . These soils were <br /> initially described in the Montrose, Colorado area. Because of the <br /> large acreages requiring soils/range correlations and vegetation <br /> production information, a double sampling technique as specified in the <br /> National Range Handbook was used. In this method, a study area within a <br /> typical example of the soil taxonomic unit is selected and a minimum of <br /> ten (10) random sample plots are located. Weights for the species <br /> occurring in each plot are estimated and recorded. After the estimates <br /> are completed, a minimum of two plots are harvested in order to <br /> determine a correction factor for the estimates. Final values are <br /> presented as air-dry pounds per acre per species for all plots. <br /> Because of the large areal extent of the soil survey area, intensive <br /> sampling is beyond the resources of the Soil Conservation Service. <br /> There are also significant acreages of both the Shavano and Persayo <br /> soils scattered throughout the survey area. Discussions with John <br /> Murray, SCS Range Conservationist at Montrose, Colorado, Barb Cencich, <br /> Soils Party Leader at Montrose, and Gib Bowman, SCS State Soils <br /> Correlator in Denver, indicated that the vegetation sampling efforts <br /> were more intensive on this soil survey than in past efforts . They also <br /> feel confident that the potential production values presented on the SCS <br /> Form 5's are representative. Additional personnel who worked on this <br /> survey are Harmon Hodgkinson, former SCS Area Range Conservationist, <br /> Grand Junction, Colorado, and Jim Kellogg, SCS Area 1 Range <br /> Conservationist, Grand Junction, Colorado. <br /> The use of a technical standard for production based on potential <br /> productivity of various soils has been approved by the New Mexico Mining <br /> and Minerals Division (Bob Sivinski , personal communication) . There are <br /> two mines using this method as the approved standard with at least five <br /> mines submitting or awaiting approval for use of a similar production <br /> standard. Peabody's Black Mesa Mine in Arizona has proposed a similar <br /> technical standard to OSM for production based on soils productivity. <br /> While formal approval of the standard along with this permit is pending, <br /> the concept of this technical standard has been accepted by OSM. <br /> 22 <br />