Laserfiche WebLink
4.5.1 Irrigated Pastureland Reference Area Soil Production Factors <br />Jim Boyd, the local NRCS representative, reviewed the capability of all soils in the reference area <br />and in the reclaimed area and assigned a relative factor to each of these soils. This letter is <br />included in this subsection. As can be seen from the letter, some soils are more productive than <br />others. The soil types are based on the USDA - NRCS Soil Survey of San Miguel Area, which was <br />compiled in the field from 1978 to 1984. The report was published in 1986. This survey can be <br />obtained on the internet at http: // offices.usda.gov/ scripts /ndISAPI.dll /oip_public /USA_map. <br />Assignment of a relative production factor to each soil type allows for the calculation of an acreage <br />weighted relative production factor for the entire reference area, and for an entire irrigated <br />pastureland bond release block(based on the soil types in the bond release block prior to mining). <br />The table below shows how the weighted average production factor for the reference area is <br />calculated. The same procedure is used to calculate a weighted average production factor for an <br />irrigated pastureland bond release block. Narrative following the table explains how the weighted <br />average factors are used to adjust the reference area sample mean for bond release <br />comparisons. The adjustment procedure elevates the production success standard in situations <br />where premining soils were potentially more productive than reference area soils, and lowers the <br />standard in situations where premine soils were on average potentially less productive than <br />reference area soils. <br />PR -06 June 2010 2.05.4(2)(e) - 23 <br />