SU0012770 (2) - Laserfiche WebLink

Home Browse Search

PRELIMINARY SUBJECT TO CHANGE CJ-134 - Cogna loam, 0 to 2 percent slopes . This very deep , well drained soil is on nearly level low fan terraces . it formed in alluvium from mixed rock sources . A few areas are d i ssecte d by intermittent sloughs that have been f i l l ed because of I and- i eve I i ng . Elevation i s 40 to 110 feet . The average annual prec. i p i tat i on is about 16 inches ,chaes , the average annual air- temperature is about 60 degrees: F, and the average frost-free period is about 270 days . TYp i ca I 1 y, the upper- 13 inches of the surface layer- is dart:_ grayish brown loam . The 1 over- 12 inches is dark brown loam. The upper 13 inches of the G.cnder l y i ng material is brown clay loam . The lower part to a depth of 64 inches is pale brown and brown loam. In some areas the surface layer is clay loam or silt loam. Included in this: unit are sma I l areas of Archerda l e and VignErlo soils on similar positions and Columbia soi l s on slightly lower positions . Also included are small areas of C:ogna so i I s with hardl. an below 40 inches . In an i nc i sed drainage area near- Farmington , there is a similar- soil that :',�� has 1to 20 percent fine sane or coarser throughout the pr of i I e . Included areas make up about 15 percent of the total acreage . Permea.b i l i ty of this Cogna soil is moderate . Available water capacity is high . Effective rooting depth is 60 inches or more . Runoff in slow and the hazard of water erosion is s I i ght . The water- intake family for i rr- i gat i on is 1 .0. The soil is subject to rare flooding which occurs during years f abnormally high precipitation ., Most areas of this unit are used for irrigated cropland and orchards . A few areas are used for homes i to development . This unit is we 1 I suited to irrigated row, field and orchard crops . It has few limitations . 4=urrow, border , corrugation and sprinkler irrigation systems are suited to this soil . Return i n j crop residue to the soil or regularly adding ether- organic matter- improves fertility, reduces crusting and increases the water- intake rate . If this unit is used for homesite development , general management considerations include rare flooding . Roads and streets should be located above the expected flood 1 eve l . The reap unit is in capa.b i l i ty units I (MLRA-17) , irrigated and IVc-1 (h4L_RA-17) , nonirrigated . This reap unit is vegetative soil group A. i I