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94 Soil Survey
<br /> considerations include the hazard of soil blowing. Most areas are used for livestock grazing. A few
<br /> Because this soil is subject to differential subsidence, areas are used for homesite development. This unit
<br /> frequent leveling of the fields is needed to improve the may provide wetland functions and values. These
<br /> efficiency of irrigation. Areas adjacent to levees are should be considered in plans for enhancement of
<br /> subject to lateral seepage in wet years when the water wildlife habitat or land use conversion.
<br /> level is high. Careful applications of irrigation water are Where this unit is used for livestock grazing, general
<br /> needed to prevent the buildup of a high water table. management considerations include the hazard of
<br /> Large ditches and small spud ditches provide erosion, the limited depth, and the very low available
<br /> subirrigation and improve drainage. Because of the water capacity. The characteristic plant community is
<br /> restricted permeability, water applications should be mainly soft chess, ripgut brome, wild oat, and filaree.
<br /> regulated so that the water does not stand on the Grazing should be controlled so that desirable
<br /> surface and damage the crops. Subirrigation, furrow, vegetation, such as soft chess, is maintained and
<br /> border, and sprinkler systems are suitable. Where a enough vegetation is left standing to protect the soil
<br /> subirrigation system is used, the water table is raised to from erosion. Loss of the surface layer results in a
<br /> a depth of 1 foot at planting time and then is slowly severe decrease in productivity and in the potential of
<br /> lowered during the growing season until it is at a depth the unit to produce plants suitable for grazing. Fencing
<br /> of about 5 feet at harvest time. When the wind velocity is difficult because of the depth to bedrock. The very
<br /> is high in spring, the hazard of soil blowing can be low available water capacity limits the production of
<br /> reduced by properly managing all crop residue and by desirable forage plants.
<br /> minimizing tillage. Levees should be checked If this unit is used for homesite development, the
<br /> periodically, and a proper maintenance program should main limitation is the depth to bedrock. General
<br /> be developed. management considerations include the hazard of
<br /> This map unit is in capability units Illw-5 (MLRA-16), erosion. The cuts needed to provide essentially level
<br /> irrigated, and IVw-5 (MLRA-16), nonirrigated. It is in building sites can expose the bedrock. Because of the
<br /> vegetative soil group E. depth to bedrock, the size of septic tank absorption
<br /> fields should be increased or specially designed
<br /> 206—Pentz sandy loam, 2 to 15 percent slopes. sewage disposal systems should be used. Excavation
<br /> This shallow, well drained, undulating to rolling soil is for roads and buildings increases the hazard of erosion.
<br /> on hills. It formed in material weathered from basic This map unit is in capability subclass We
<br /> andesitic, tuffaceous sandstone. The native vegetation (MLRA-18), nonirrigated. It is in vegetative soil group G.
<br /> is mainly annual grasses and forbs. Elevation is 135 to
<br /> 300 feet. The average precipitation is about 16 inches, 207—Pentz sandy loam, 15 to 50 percent slopes.
<br /> the average annual air temperature is 60 degrees F, This shallow, well drained, moderately steep and steep
<br /> and the average frost-free period is about 270 days. soil is on hills, It formed in material weathered from
<br /> Typically, the surface layer is brown sandy loam basic andesitic, tuffaceous sandstone. Slopes are
<br /> about 4 inches thick. The subsoil is brown and light convex. Areas are narrow and sinuous and descend
<br /> yellowish brown loam about 11 inches thick, Light gray, from the adjacent high terraces. Strongly consolidated
<br /> moderately consolidated, basic andesitic, tuffaceous strata crop out as bands across the slopes in some
<br /> sandstone bedrock is at a depth of 15 inches. In some areas. The native vegetation is mainly annual grasses
<br /> areas the surface layer is fine sandy loam, gravelly and (orbs and includes blue oak in most areas.
<br /> sandy loam, or loam. Elevation is 170 to 360 feet. The average annual
<br /> Included in this unit are small areas of Alamo soils in precipitation is about 17 inches. The average annual air
<br /> drainageways; Bellota, Pardee, and Redding soils on temperature is about 60 degrees F, and the average
<br /> terraces; Peters soils in the slightly lower landscape frost-free period is about 270 days.
<br /> �- positions; and Lithic Xerorthents in convex positions Typically, the surface layer is brown sandy loam
<br /> near the top of the slopes, Also included are small about 4 inches thick. The subsoil is brown and light
<br /> areas of deep or very deep, moderately fine textured yellowish brown loam about 11 inches thick. Light gray,
<br /> _ soils on concave toe slopes. Included areas make up andesitic, tuffaceous sandstone bedrock is at a depth of
<br /> about 15 percent of the total acreage. 15 inches. In some areas the surface layer is loam,
<br /> Permeability is moderately rapid in the Pentz soil. gravelly loam, or gravelly sandy loam.
<br /> Available water capacity is very low. The effective Included in this unit are small areas of Bellota and
<br /> rooting depth is limited by the bedrock at a depth of 10 Keyes soils at the base of the slopes and Pardee and
<br /> to 20 inches. Runoff is slow or medium, and the hazard Redding soils on high terrace remnants. Also included
<br /> of water erosion is slight or moderate, are small areas of Lithic Xerorthents and exposed
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