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r San Joaquin County, California to lateral seepage in wet years when the water level is high. Careful applications of irrigation water are needed to prevent the buildup of a high water table. Tile drainage can lower the water table if a suitable outlet is available. Furrow, border, and sprinkler irrigation systems are suitable. When the wind velocity is high in spring, the hazard of soil blowing can be reduced by properly managing all crop residue and by minimizing tillage. The Egbert soil is in capability units Ilw-2 (MLRA-17), irrigated, and IVw-2 (MLRA-17), nonirrigated. It is in vegetative soil group C. The Urban land is not assigned a capability classification or a vegetative soil group. 156—El Solyo clay loam, 0 to 2 percent slopes. .. This very deep, well drained, nearly level soil is on low alluvial fans. It formed in alluvium derived from sedimentary rock sources. Elevation is 60 to 300 feet. ` The average annual precipitation is about 10 inches, the average annual air temperature is about 60 degrees F, and the average frost -free period is about 270 days. Typically, the surface layer is grayish brown clay loam about 10 inches thick. The subsoil to a depth of 60 inches is brown and pale brown silty clay loam. The soil is calcareous between depths of 10 and 60 inches. In some areas the surface layer is silty clay loam. Included in this unit are small areas of Stomar, Vernalis, and Zacharias soils on the slightly higher parts of the landscape. Also included, in landscape positions similar to those of the EI Solyo soil, are small areas of soils that have a moderately fine textured surface layer and have a gravelly or very gravelly moderately fine textured substratum below a depth of 40 inches. Included areas make up about 15 percent of the total acreage. r, Permeability is slow in the EI Solyo soil. Available water capacity is very high. The shrink -swell potential is high. The effective rooting depth is 60 inches or more. Runoff is slow, and the hazard of water erosion is slight. The rate of water intake in irrigated areas is 0.5 inch per hour. Most areas of this unit are used for irrigated crops or orchards. A few areas are used for homesite development or for dryland grain crops. This unit is suited to irrigated row, field, and orchard .crops. The main limitation is the slow permeability. Because of the restricted permeability, water applications should be regulated so that the water does not stand on the surface and damage the crops. The soil should be cultivated only within a narrow range of moisture content. It is too sticky when wet and too hard when dry. Furrow, border, and sprinkler irrigation rsystems are suitable. Returning crop residue to the soil r 59 or regularly adding other organic material improves fertility, minimizes crusting, and increases the rate of water intake. If this unit is used for homesite development, the main limitations are the slow permeability, low strength, and the high shrink -swell potential. On sites for septic tank absorption fields, the slow permeability can be overcome by increasing the size of the absorption field, backfilling the trench with sandy material, and installing long absorption lines. Properly designing buildings and roads can offset the limited ability of the soil to support a load. Properly designing foundations and footings and diverting runoff away from buildings help to prevent the structural damage caused by shrinking and swelling. Where this unit is used for dryland grain crops, the main limitation is low rainfall during the growing season. Because the amount of precipitation is not sufficient for annual cropping, the best suited cropping system is one that includes small grain and summer fallow. Maintaining crop residue on or near the surface helps to prevent excessive runoff and helps to maintain tilth and the organic matter content. This map unit is in capability units IIs -3 (MLRA-17), irrigated, and IVs -3 (MLRA-17), nonirrigated. It is in vegetative soil group A. 157—Exeter sandy loam, 0 to 2 percent slopes. This moderately well drained, nearly level soil is on low terraces. It is moderately deep to a hardpan. It formed in alluvium derived from mixed rock sources. A few areas are dissected by intermittent sloughs that have been filled as a result of land leveling. Elevation is 20 to 100 feet. The average annual precipitation is about 15 inches, the average annual air temperature is about 60 degrees F, and the average frost -free period is about 270 days. Typically, the surface layer and the upper part of the subsoil are dark brown and brown sandy loam about 26 inches thick. The next part of the subsoil is brown sandy clay loam and loam about 7 inches thick. The lower part to a depth of 60 inches is a brown, indurated hardpan. In some areas the surface layer is loam. Included in this unit are small areas of Kingdon and Acampo soils in the slightly lower landscape positions and Madera and San Joaquin soils on terraces. Also included are a few areas where depth to the hardpan is as little as 15 inches, mainly where deep leveling cuts have been made. Included areas make up about 15 percent of the total acreage. Permeability is moderate in the Exeter soil. Available water capacity is low. The effective rooting depth is limited by the hardpan at a depth of 20 to 40 inches. Depth to the water table is more than 6 feet, but water