2010-11-17_REVISION - C1981008 (3)

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12"rajoo S L M MON 11:58 FAX 303 236 28ad MRCS COLO s0 6. The soils are not flooded freguently during the growing season (less often than once, in 2 years) ; ond, 7. The product of K (erodibility factor) x ercent slope is less than 2.0, and the product of Y (soilz erodibility} x C (climatic factor) does not exceed 60; and, 8. The soils have a permeability rote of at least 0.06 inch (0;15 cm) per hour in the upper 20 inches (50 en) and the mean annual soil temperature at a depth of 20 inches (50 cm) is less than 590P (1soo ; the permeability rate ig not a limiting factor if the mum annual soil remperatuxe is 590F CIS C) or higher;. and, ; 9. Less than 10 percent of the surface layer (upper 6 Inches) in these soj s consists of rock fragments coarser than 3 inches (7.6 cm). The following- modifications and/or interpretations of the National Criteria for Prime Farmlands were used in Colorado. The soil must have; 1. A developed irrigation water supply that-is dependable and adequate to meet moisture requirements 8 out of 10 years arui have 4 inches or more available water capacity within a depth of 40 inches (1 meter), or within the root zone if the -root zone is less than 40 inches; 2. A growing season of 90 days or more; 3. No water liable or the water table is below a depth of 1.5 feet and drainage is. possible; 4. A conductivity, of 8 mmhos /cm or less in the upper 40 inches and per= ability is greater than .2 inches /hr. (moderately slow or greater) if the slope is less than 2 percent. These souls are considered capable of being managed so that all horizons within a depth of 40 inches,(1 meter) or in the root zone • if it is less than 40 inches will have a conductivity of the saturated extract of less than 4 mahos /cm and the exchangeable sodium percentage (ESP) is less than 15; irrigated sails with bedrock within 40 inches of the surface and soil horizons that have a pH higher than g.4 are considered as having high conductivity and therefore not prime; 5, slope of irrigated prime farmland will not exceed 6 percent, Unique Farmland. Unique Farmland is land other than Prime Farmland.that is used for the production of specific high value food and fiber craps. it has the special combination of soil quality, location, grow14 season, and moisture supply needed to economically produce sustained high quality and/or high yield of a specific crop, when treated and managed according to acceptable farming methods. Two areas in Colorado are considered Unique Farmlands of National Importance -- the fruit orchards in the Grand Valley and the Delta- Montrose areas, and the seed potato and fruit and vegetable producing areas of the San Luis Valley. 3 1600,5