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26 Soil Survey areas have little or no soil material and support little or feet, but water may be briefly perched above the no vegetation. Pits, gravel, is an example. hardpan after periods of heavy rainfall or irrigation. Miscellaneous areas are shown on the soil maps. Some Runoff is slow, and the hazard of water erosion is that are too small to be shown are identified by a slight. The rate of water intake in irrigated areas is 1.5 y special symbol on the soil maps. inches per hour. The hazard of soil blowing is This survey area was mapped at one level of detail, moderate. but the minimum size allowed for the delineations Most areas are used for irrigated crops, orchards, or y differed, depending on anticipated long-term uses. vineyards. A few areas are used for homesite Areas used for intensive agriculture have a 10-acre development. This unit may provide wetland functions minimum delineation. Areas that are used less and values. These should be considered in plans for intensively, such as rangeland, and areas that are so enhancement of wildlife habitat or land use conversion. intensively used that onsite investigation is needed, This unit is suited to irrigated row, field, orchard, and such as those used for urban development, have a 20- vineyard crops. The main limitation is depth to the acre minimum delineation. Strongly contrasting soils in hardpan. General management considerations include areas as small as 10 acres, however, were identified. the hazard of soil blowing. The hardpan limits the Table 5 gives the acreage and proportionate extent suitability for deep-rooted crops. Where feasible, deep of each map unit. Other tables (see "Summary of ripping of this restrictive layer can help to overcome this Tables") give properties of the soils and the limitations, limitation. A tillage pan forms easily if the soil is tilled capabilities, and potentials for many uses. The when wet. Chiseling or subsoiling breaks up the pan. "Glossary" defines many of the terms used in Furrow, border, and sprinkler irrigation systems are describing the soils. suitable. Careful applications of irrigation water are needed to prevent the buildup of a high water table. Soil Descriptions When the wind velocity is high in spring, the hazard of soil blowing can be reduced by properly managing all 101—Acampo sandy loam, 0 to 2 percent slopes. crop residue and by minimizing tillage. This moderately well drained, nearly level soil is on low If this unit is used for homesite development, the fan terraces. It is deep to a hardpan. It formed in main limitation is depth to the hardpan. Ripping the alluvium derived from granitic rock sources. A few areas hardpan improves permeability and thus also improves are dissected by intermittent sloughs that have been the suitability of the soil for septic tank absorption fields. filled as a result of land leveling. Elevation is 10 to 150 This map unit is in capability units IIs-8 (MLRA-17), feet. The average annual precipitation is about 15 irrigated, and IVs-8 (MLRA-17), nonirrigated. It is in inches, the average annual air temperature is about 60 vegetative soil group A. degrees F, and the average frost-free period is about 260 days. 102—Alamo clay, 0 to 2 percent slopes. This poorly Typically, the surface layer is brown sandy loam drained, nearly level soil is in basins and drainageways about 19 inches thick. The upper part of the subsoil is on old terraces. It is moderately deep to a hardpan. It pale brown and light yellowish brown sandy loam, which formed in alluvium derived from mixed rock sources. extends to a depth of 47 inches. The next part is an The native vegetation is mainly annual grasses and indurated hardpan, which extends to a depth of 49 forbs. Meandering drainageways and closed inches. The lower part to a depth of 60 inches is a depressions fill with water to form vernal pools. variegated brownish yellow and yellowish brown, weakly Elevation is 100 to 115 feet. The average annual cemented to strongly cemented hardpan. In some areas precipitation is about 14 inches, the average annual air the surface layer is fine sandy loam or loam. temperature is about 61 degrees F, and the average Included in this unit are small areas of Devries and frost-free period is about 275 days. Tujunga soils in the slightly lower landscape positions Typically, the surface layer is dark gray clay about 12 and small areas of moderately coarse textured soils that inches thick. The upper part of the subsoil is gray clay, have a moderately fine textured subsoil. Also included which extends to a depth of 33 inches. The lower part are small areas of Tokay soils in landscape positions to a depth of 60 inches is a pale brown and brown, similar to those of the Acampo soil. Included areas indurated, silica-cemented hardpan. In some areas the make up about 15 percent of the total acreage. surface layer is silty clay or silty clay loam. Permeability is moderately rapid in the Acampo soil. Included in this unit are small areas of Madera, San Available water capacity is moderate. The effective Joaquin, and Redding soils on the slightly higher rooting depth is limited by the hardpan at a depth of 40 terraces. Also included are small areas of Alamo soils to 60 inches. Depth to the water table is more than 6 in vernal pools that pond in the winter. Included areas