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' San Joaquin County, California 99
<br /> ' flooding, which occurs during years of abnormally high degrees F, and the average frost-free period is about
<br /> precipitation. 270 days.
<br /> Most areas are used for irrigated crops. This unit Typically, the surface layer is grayish brown clay
<br /> may provide wetland functions and values. These loam about 16 inches thick. The subsoil and the
<br /> ' should be considered in plans for enhancement of underlying material to a depth of 60 inches are grayish
<br /> wildlife habitat or land use conversion. brown and brown clay loam. In some areas the surface
<br /> This unit is suited to irrigated row and field crops. layer is gravelly clay loam, gravelly loam, or loam.
<br /> ' The main limitations are the low available water Included in this unit are small areas of Carbone and
<br /> capacity, the high water table, and the weakly cemented Calla soils in landscape positions similar to those of the
<br /> subsoil. General management considerations include Pleito soil. Also included are small areas of Pleito soils
<br /> the hazard of soil blowing. Because the soil is droughty, that have slopes of 0 to 2 or 8 to 15 percent. The areas
<br /> applications of irrigation water should be light and where slopes are 0 to 2 percent are in drainageways,
<br /> frequent. Areas adjacent to levees are subject to lateral and the areas where slopes are 8 to 15 percent are on
<br /> seepage in wet years when the water level is high. the slightly higher parts of the landscape. Included
<br /> Careful applications of irrigation water are needed to areas make up about 15 percent of the total acreage.
<br /> prevent the buildup of a high water table. Tile drainage Permeability is moderately slow in the Pleito soil.
<br /> can lower the water table if a suitable outlet is available. Available water capacity is very high. The effective
<br /> The weakly cemented subsoil reduces the yield of rooting depth is 60 inches or more. Runoff is medium,
<br /> deep-rooted crops. Where feasible, deep ripping of this and the hazard of water erosion is slight or moderate.
<br /> restrictive layer can help to overcome this limitation. The rate of water intake in irrigated areas is 0.5 inch
<br /> Subirrigation, furrow, border, and sprinkler systems are per hour.
<br /> suitable. When the wind velocity is high in spring, the Most areas of this unit are used for livestock grazing.
<br /> hazard of soil blowing can be reduced by properly A few areas are used for dryland grain crops. If
<br /> managing all crop residue and by minimizing tillage. irrigation water is available, the unit can be used for
<br /> Levees should be checked periodically, and a proper irrigated crops.
<br /> ' maintenance program should be developed. Where this unit is used for livestock grazing, general
<br /> This map unit is in capability unit IVw-4 (MLRA-16), management considerations include the clay loam
<br /> irrigated and nonirrigated. It is in vegetative soil group surface layer. The characteristic plant community is
<br /> mainly soft chess, red brome, wild oat, and filaree.
<br /> Trampling of the clay loam surface layer by livestock
<br /> 214—Pits, gravel. These are open excavations from when the soil is too wet reduces productivity and
<br /> which soil and the underlying material have been increases the runoff rate.
<br /> ' removed and other material that supports few or no Where this unit is used for dryland grain crops, the
<br /> plants have been exposed. The pits are in scattered main limitation is low rainfall during the growing season.
<br /> areas throughout the county. General management considerations include the hazard
<br /> ' Included in this unit are small areas of Dumps and of erosion. Because the amount of precipitation is not
<br /> Xerorthents. Included areas make up about 15 percent sufficient for annual cropping, the best suited cropping
<br /> of the total acreage. system is one that includes small grain and summer
<br /> Soil properties, such as permeability, drainage, fallow. All tillage should be on the contour or across the
<br /> 1 runoff, effective rooting depth, and available water slope. Leaving crop residue on or near the surface
<br /> capacity, vary from one area to another. This unit is helps to conserve moisture, maintain filth, and control
<br /> poorly suited to most land uses. erosion.
<br /> ' This map unit is not assigned a capability Where this unit is used for irrigated row, field, or
<br /> classification or a vegetative soil group_ orchard crops, general management considerations
<br /> include the hazard of erosion. All tillage should be on
<br /> 215—Pleito clay loam, 2 to 8 percent slopes. This the contour or across the slope. Sprinkler and drip
<br /> ' very deep, well drained, gently sloping and moderately irrigation systems are suitable. They permit an even,
<br /> sloping soil is on dissected terraces. It formed in controlled application of water, help to prevent
<br /> alluvium derived from mixed rock sources. The excessive runoff, and minimize the risk of erosion.
<br /> ' vegetation in areas that have not been cultivated is Returning crop residue to the soil or regularly adding
<br /> mainly annual grasses and (orbs. Elevation is 150 to other organic material improves fertility, minimizes
<br /> 600 feet. The average annual precipitation is about 10 crusting, and increases the rate of water intake.
<br /> inches, the average annual air temperature is about 60 This map unit is in capability units Ile-1 (MLRA-17),
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