Detailed Soil Map Units (SS of Dade, Florida)

The map units on the detailed soil maps at the back of this survey represent the soils in the survey area. The map unit descriptions in this section, along with the soil maps, can be used to determine the suitability and potential of a soil for specific uses. They also can be used to plan the management needed for those uses. More information on each map unit, or soil, is given under the heading "Use and Management of the Soils."

Each map unit on the detailed soil maps represents an area on the landscape and consists of one or more soils for which the unit is named.

A number identifying the soil precedes the map unit name in the soil descriptions. Each description includes general facts about the soil and gives the principal hazards and limitations to be considered in planning for specific uses.

Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer or of the underlying material, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement.

Soils of one series can differ in texture of the surface layer or of the underlying material. They also can differ in slope, stoniness, salinity, wetness, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Perrine marl is a phase of the Perrine series.

Some map units are made up of two or more major soils. These map units are called soil complexes. A soil complex consists of two or more soils, or one or more soils and a miscellaneous area, in such an intricate pattern or in such small areas that they cannot be shown separately on the soil maps. The pattern and proportion of the soils are somewhat similar in all areas. Biscayne-Rock outcrop complex is an example.

Most map units include small scattered areas of soils other than those for which the map unit is named. Some of these included soils have properties that differ substantially from those of the major soil or soils. Such differences could significantly affect use and management of the soils in the map unit. The included soils are identified in each map unit description. Some small areas of strongly contrasting soils are identified by a special symbol on the soil maps.

This survey includes miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Urban land is an example. Miscellaneous areas are shown on the soil maps. Some that are too small to be shown are identified by a special symbol on the soil maps.

Table 2 gives the acreage and proportionate extent of each map unit. Other tables (see "Summary of Tables") give properties of the soils and the limitations, capabilities, and potentials for many uses. The "Glossary" defines many of the terms used in describing the soils.

Index to Map Units

2. Biscayne gravelly marl, drained
3. Lauderhill muck, depressional
4. Pennsuco marl, drained
5. Pennsuco marl
6. Perrine marl, drained
7. Krome very gravelly loam
9. Udorthents-water complex
10. Udorthents, limestone substratum-Urban land complex
11. Udorthents, marl substratum-Urban land complex
12. Perrine marl
13. Biscayne marl
14. Dania muck, depressional
15. Urban land
16. Biscayne marl, drained
18. Tamiami muck, depressional
20. Cardsound-Rock outcrop complex
22. Opalocka-Rock outcrop complex
23. Chekika very gravelly loam
24. Matecumbe muck
25. Biscayne-Rock outcrop complex
26. Perrine marl, tidal
28. Demory-Rock outcrop complex
30. Pahokee muck, depressional
31. Pennsuco marl, tidal
32. Terra Ceia muck, tidal
33. Plantation muck
34. Hallandale fine sand
35. Margate fine sand
37. Basinger fine sand
38. Rock outcrop-Vizcaya-Biscayne complex
39. Beaches
40. Pomello sand
41. Dade fine sand
42. Udorthents, limestone substratum, 0 to 5 percent slopes
45. Canaveral sand
47. St. Augustine sand
48. Kesson muck, tidal

2—Biscayne gravelly marl, drained.

This very shallow, nearly level, poorly drained soil is on broad, low flats, in sloughs, and in transverse glades that extend from the Pineland Ridge. Individual areas are irregularly shaped or rectangular and range from 6 to 100 acres in size. Slopes are smooth or concave and are less than 2 percent.

On 95 percent of the acreage mapped as Biscayne gravelly marl, drained, Biscayne and similar soils make up 78 to 99 percent of the mapped areas.

Typically, the surface layer is about 7 inches of dark gray gravelly marl that has a texture of silt loam. It is underlain by hard, porous limestone having less than 20 percent solution holes that are 4 to 12 inches deep and 6 to 18 inches wide and contain very dark grayish brown silty clay. The content of limestone fragments is mainly 15 to 25 percent, by volume, but ranges to as much as 35 percent. The fragments range from 2 millimeters to 7.5 centimeters in diameter.

Included in mapping are soils that are similar to Biscayne gravelly marl, drained, but have less than 15 or more than 35 percent gravel, by volume, are ponded and may have a continuous layer or layers of organic material that are more than 8 inches thick but make up less than half of the total soil depth, or have limestone bedrock at a depth of 20 to 40 inches.

Dissimilar soils that are included with this soil in mapping occur as small areas of Chekika and Pennsuco soils. Also included are areas of Rock outcrop. Dissimilar inclusions make up 1 to 22 percent of most mapped areas. Chekika soils are somewhat poorly drained and are in the higher positions on the landscape. Pennsuco soils are on broad, low coastal flats. They are deep or very deep.

The water table in the Biscayne soil remains within 10 inches of the surface for 2 to 4 months during most years, receding to as deep as 36 inches during dry periods. Permeability is moderate.

All areas have been drained, rock-plowed or mechanically scarified, and cultivated at some time in the past. The natural vegetation no longer remains. Abandoned fields rapidly become overgrown with thick stands of Brazilian pepper, leatherleaf fern, and a variety of shrubs, broadleaf weeds, and grasses.

In most areas a water-control system has been installed. If the water-control system is properly maintained, this soil is well suited to a variety of shallow-rooted cultivated crops. Much of the cultivated acreage is used for corn, snap beans, potatoes, malanga, or bananas. Land grading and smoothing fill in the small depressions that are common in areas of this soil and thus generally permit more efficient use of farm equipment and more uniform application of irrigation water. Yearly rock-plowing may be necessary to incorporate some of the finer textured soil material in solution holes. Bedding is necessary if root crops are grown. Returning crop residue to the soil or regularly adding other organic material improves fertility and tilth. Disking during wet periods normally results in cloddiness. Important management practices include preparing a good seedbed and applying fertilizer according to the results of soil tests and the needs of the crop. Because of a high pH, some micronutrients may not be available to certain crops. Boron toxicity may affect some crops.

This soil is poorly suited to the production of ornamental trees and shrubs for nursery stock because of the depth to bedrock. It is poorly suited to the production of citrus and mangos because of the wetness. It is unsuited to the production of avocados.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor. Deferred grazing during wet periods helps to prevent compaction of the soil.

This soil is not used as rangeland or forest land. It is in the Sawgrass Marsh and Freshwater Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material are needed to overcome these limitations.

The capability subclass is IIIw.

3—Lauderhill muck, depressional.

This moderately deep, nearly level, very poorly drained soil is in narrow drainageways and broad open areas within sawgrass marshes. It is ponded for 9 to 12 months in most years. Individual areas are long and narrow or broad and irregularly shaped and range from 10 to several thousand acres in size. Slopes are smooth or concave and are less than 2 percent.

On 95 percent of the acreage mapped as Lauderhill muck, depressional, Lauderhill and similar soils make up 98 to 99 percent of the mapped areas.

Typically, the soil is muck to a depth of about 30 inches. The upper 7 inches is black, and the lower 23 inches is very dark brown. Hard, porous, oolitic limestone bedrock is at a depth of about 30 inches.

Included in mapping are soils that are similar to Lauderhill muck but are more than 36 or less than 20 inches deep over limestone bedrock, may be saline because of a close proximity to the coast, or have continuous layers of marl more than 4 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne, Matecumbe, Pennsuco, and Perrine soils. Dissimilar soils make up 2 percent or less of most mapped areas. Biscayne and Perrine soils are in positions on the landscape similar to those of the Lauderhill soil. They are made up of marl. Biscayne soils are shallow over bedrock, and Perrine soils are moderately deep over limestone bedrock. Matecumbe soils are in the higher positions on the landscape and are moderately well drained. Pennsuco soils are in the slightly higher positions on the landscape. They are made up of marl and are deep or very deep over limestone bedrock.

Under natural conditions, the Lauderhill soil is ponded for 9 to 12 months during most years. The water table is within 10 inches of the surface for the rest of the year. Permeability is rapid. If drained, the organic material initially shrinks to about half the original thickness and then subsides further as a result of compaction and oxidation. These losses are most rapid during the first 2 years. If drained, the soil continues to subside at a rate of about 1 inch per year. The lower the water table, the more rapid the loss.

Most areas support natural vegetation, which consists of cattail and sawgrass. Areas that have been drained or disturbed, however, may be dominated by Brazilian pepper and melaleuca. Areas of this soil provide cover for deer and excellent habitat for wading birds and other kinds of wetland wildlife.

Under natural conditions, this soil generally is not suited to cultivation. If water is controlled through a system of dikes, ditches, and pumps, however, the soil is well suited to most winter vegetable crops. A well designed and maintained water-control system can remove excess water during periods when crops are growing on the soil and can keep the soil saturated at all other times. Keeping the soil saturated minimizes oxidation. Important management practices include good seedbed preparation and a suitable crop rotation. Cover crops and crop residue should be left on the surface or plowed under. Fertilizer should be applied according to the needs of the crop.

This soil is not suited to the production of citrus, avocados, or pine trees because of the wetness.

This soil is not used as rangeland. It is in the Freshwater Marsh ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the bonding, excess humus, subsidence, low strength, and the depth to bedrock. Water-control measures are needed to prevent bonding. The organic material should be removed, and suitable backfill material should be provided. Sealing or lining sewage lagoons and trench sanitary landfills with impervious soil material helps to prevent seepage. The sides of shallow excavations should be shored. Mounding may be needed on sites for septic tank absorption fields.

The capability subclass is VIIw.

4—Pennsuco marl, drained.

This deep, nearly level, poorly drained soil is on broad, low coastal flats and in transverse glades. Individual areas are broad and irregularly shaped and range from 10 to 350 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Pennsuco marl, drained, Pennsuco and similar soils make up 87 to 99 percent of the mapped areas.

Typically, the surface layer is about 8 inches of dark grayish brown marl that has a texture of silt loam. The underlying material extends to a depth of about 44 inches. It is marl that has a texture of silt loam. It is grayish brown in the upper 19 inches and dark gray in the lower 17 inches. Common very pale brown, soft accumulations of calcium carbonate are between depths of 8 and 44 inches. Common very dark gray pockets and vertical streaks are below a depth of about 27 inches. Soft, porous limestone bedrock is at a depth of about 44 inches.

Included in mapping are soils that are similar to Pennsuco marl, drained, but have limestone bedrock at a depth of less than 40 or more than 80 inches or are ponded and in the upper 40 inches may have continuous layers of muck that are more than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne and Lauderhill soils and small areas of Udorthents. Dissimilar soils make up 1 to 13 percent of most mapped areas. Biscayne soils are in positions on the landscape similar to those of the Pennsuco soil. They are shallow or very shallow over limestone bedrock. Lauderhill soils are in the lower positions on the landscape. They have an organic surface layer. Udorthents are in the slightly higher areas of mineral fill material.

During most years the water table in the Pennsuco soil remains within a depth of 10 inches for 2 to 4 months and is at a depth of 10 and 40 inches for the rest of the year. Permeability is moderately slow.

All areas have been drained and cultivated at some time in the past. The native vegetation no longer remains. Abandoned fields quickly become overgrown with thick stands of Brazilian pepper, Australian pine, leatherleaf fern, and a variety of shrubs, broadleaf weeds, sedges, and grasses.

A water-control system has been installed in most areas. If the water-control system is properly maintained, this soil is well suited to a variety of cultivated vegetable and grain crops. Much of the cultivated acreage is used for corn, potatoes, snap beans, sorghum, malanga, or ornamental trees and shrubs. Land grading and smoothing fill in the small depressions that are common in areas of this soil and thus improve surface drainage and permit more efficient use of farm equipment and more uniform application of irrigation water. Bedding generally is necessary if ornamental plants or root crops are grown. Returning crop residue to the soil or regularly adding other organic material improves fertility and tilth and increases the rate of water intake. Prolonged cultivation with heavy equipment can result in the formation of a tillage pan. Subsoiling during dry periods helps to break up the pan and thus permits deeper root penetration. Disking during wet periods often results in cloddiness. Important management practices include preparing a good seedbed, applying fertilizer according to the results of soil tests and the needs of the crop, and controlling weeds and brush. Because of a high pH, some micronutrients may not be available to certain crops. Boron toxicity may affect some crops.

Figure 4.—Sorghum in an area of Pennsuco marl, drained. (gif, 91 KB)

This soil is poorly suited to the production of citrus and mangos because of the wetness. It is unsuited to the production of avocados.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor. Deferred grazing during wet periods helps to prevent compaction of the soil.

This soil generally is not used as rangeland or forest land. Under natural conditions, it is in the Freshwater Marsh and Sawgrass Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material generally are needed to overcome these limitations.

The capability subclass is IIIw.

5—Pennsuco marl.

This deep, nearly level, very poorly drained soil is in broad, low coastal marshes and sloughs and in small depressional areas. Individual areas are broad and irregularly shaped and range from 6 to 200 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Pennsuco marl, Pennsuco and similar soils make up 99 percent of the mapped areas.

Typically, the surface layer is about 4 inches of light brownish gray marl that has a texture of silt loam and has common black streaks in old root channels. The underlying material, to a depth of about 46 inches, is light gray marl that has a texture of silt loam and has a few black streaks. The soil has common whole snail shells and shell fragments that are sand sized to 1 inch in diameter. Soft, porous limestone bedrock is at a depth of about 46 inches.

Included in mapping are soils that are similar to Pennsuco marl, but have limestone bedrock at a depth of less than 40 or more than 80 inches, in the upper 40 inches may have continuous layers of muck that are more than 8 inches thick, or have been drained.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne, Lauderhill, Pahokee, and Tamiami soils and small areas of Udorthents. Dissimilar soils make up about 1 percent of most mapped areas. Biscayne soils are in positions on the landscape similar to those of the Pennsuco soil. They are shallow or very shallow over limestone bedrock. Lauderhill, Pahokee, and Tamiami soils are in the lower positions on the landscape. They have an organic surface layer.

The water table in the Pennsuco soil remains within a depth of 6 inches for 2 to 4 months during most years and is at a depth of 10 to 30 inches for most of the rest of the year. Permeability is moderately slow.

All areas have been cleared, drained, and cultivated at some time in the past. The native vegetation no longer remains. Abandoned fields quickly become overgrown with thick stands of Brazilian pepper, Australian pine, leatherleaf fern, and a variety of shrubs, broadleaf weeds, ferns, and grasses.

A water-control system has been installed in most areas. If the water-control system is properly maintained, this soil is well suited to a variety of cultivated vegetable and grain crops. Much of the cultivated acreage is used for corn, potatoes, snap beans, sorghum, malanga, or ornamental trees and shrubs. Land grading and smoothing fill in the small depressions that are common in areas of this soil and thus improve surface drainage and permit more efficient use of farm equipment and more uniform application of irrigation water. Bedding generally is necessary if ornamental plants or root crops are grown. Returning crop residue to the soil or regularly adding other organic material improves fertility and tilth and increases the rate of water intake. Prolonged cultivation with heavy equipment can result in the formation of a tillage pan. Subsoiling during dry periods helps to break up the pan and thus permits deeper root penetration. Disking during wet periods often results in cloddiness. Important management practices include good seedbed preparation.

This soil generally is not used as rangeland or forest land. It is in the Freshwater Marsh and Sawgrass Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding. Extensive water-control measures and large amounts of suitable fill material are needed to overcome this limitation.

The capability subclass is IIIw.

6—Perrine marl, drained.

This moderately deep, nearly level, poorly drained soil is on broad, low coastal flats and in transverse glades. Individual areas are broad and irregularly shaped and range from 6 to 3,000 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Perrine marl, drained, Perrine and similar soils make up 98 to 99 percent of the mapped areas.

Typically, the surface layer is about 10 inches of grayish brown marl that has a texture of silt loam. The underlying layer, to a depth of about 26 inches, is light brownish gray marl that has a texture of silt loam. Few to many light gray, soft accumulations of calcium carbonate and few grayish brown stains are in pockets or around pores and root channels between depths of 11 and 26 inches. Soft, porous limestone bedrock is at a depth of about 26 inches.

Included in mapping are soils that are similar to Perrine marl, drained, but have limestone bedrock at a depth of less than 20 or more than 40 inches or are ponded and may have continuous layers of muck more than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Lauderhill soils and small areas of Udorthents. Dissimilar soils make up about 1 percent of most mapped areas. Lauderhill soils are in the lower positions on the landscape. They have an organic surface layer. Udorthents are in the slightly higher areas of mineral fill material.

Under natural conditions, the Perrine soil has water above the surface for 1 to 3 months during most years. During most years the water table remains within 10 inches of the surface for 2 to 4 months and is at a depth of 10 to 30 inches for most of the rest of the year. Permeability is moderately slow.

All areas have been cleared, drained, and cultivated at some time in the past. The native vegetation no longer remains. Abandoned fields quickly become overgrown with thick stands of Brazilian pepper, Australian pine, leatherleaf fern, and a variety of shrubs, broadleaf weeds, ferns, and grasses.

A water-control system has been installed in most areas. If the water-control system is properly maintained, this soil is well suited to a variety of cultivated vegetable and grain crops. Much of the cultivated acreage is used for corn, potatoes, snap beans, sorghum, malanga, or ornamental trees and shrubs. Land grading and smoothing fill in the small depressions that are common in areas of this soil and thus improve surface drainage and permit more efficient use of farm equipment and more uniform application of irrigation water. Bedding generally is necessary if ornamental plants or root crops are grown. Returning crop residue to the soil or regularly adding other organic material improves fertility and tilth and increases the rate of water intake. Prolonged cultivation with heavy equipment can result in the formation of a tillage pan. Subsoiling during dry periods helps to break up the pan and thus permits deeper root penetration. Disking during wet periods often results in cloddiness. Important management practices include preparing a good seedbed, applying fertilizer according to the results of soil tests and the needs of the crop, and controlling weeds and brush. Because of a high pH, some micronutrients may not be available to certain crops. Boron toxicity may affect some crops.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor. Deferred grazing during wet periods helps to prevent compaction of the soil.

This soil is poorly suited to the production of citrus and mangos because of the wetness. It is unsuited to the production of avocados.

This soil generally is not used as rangeland or forest land. Under natural conditions, it is in the Sawgrass Marsh and Freshwater Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material generally are needed to overcome these limitations.

The capability subclass is IIIw.

7—Krome very gravelly loam.

This very shallow, nearly level, moderately well drained soil is on broad, very low hills on the Miami Ridge. Individual areas are broad and irregularly shaped and range from 6 to 100 acres in size. Slopes are smooth and range from 0 to 2 percent.

On 95 percent of the acreage mapped as Krome very gravelly loam, Krome and similar soils make up 98 to 99 percent of the mapped areas.

Typically, the soil is dark brown very gravelly loam about 7 inches thick. Hard, porous limestone bedrock is at a depth of about 7 inches. Solution holes in the limestone extend to a depth of about 10 inches. They contain silty clay loam or silty clay.

Included in mapping are soils that are similar to the Krome soil, but contain more than 60 percent or less than 35 percent gravel or have slopes of as much as 5 percent. Also included are some areas in groves where as much as 2 inches of accumulated leaf litter is on the surface.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne, Chekika, Cardsound, and Matecumbe soils. Also included are areas of Rock outcrop. Dissimilar inclusions make up 2 percent or less of most mapped areas. Biscayne soils are in the lower positions on the landscape. They have a surface layer of marl. Chekika, Cardsound, and Matecumbe soils are in positions on the landscape similar to those of the Krome soil. They do not have a gravelly surface layer.

The water table in areas of the Krome soil is within the limestone bedrock. It is at a depth of 40 to 60 inches in most years. Permeability is moderate.

All areas have been rock-plowed or mechanically scarified and cultivated at some time in the past. The natural vegetation no longer remains. This soil is suitable for a wide variety of fruit and vegetable crops, but special management is needed. This management includes yearly rock-plowing, bedding, regularly adding fertilizer, and irrigating during the winter growing season. Because of a favorable climate, the water available for irrigation, and the demand by northern markets, this high level of management is practical.

This soil is suitable for the production of fruit and citrus, but this production requires trenching, drilling, or blasting into the limestone. Regular applications of fertilizer and irrigation water also are needed.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor.

This soil generally is not used as rangeland or forest land. It is in the Everglades Flatwoods ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the depth to bedrock and small stones. Local construction methods generally can overcome these limitations. The soil commonly is used for urban development.

The capability subclass is Vs.

9—Udorthents-water complex.

This map unit consists of Udorthents and open bodies of water. The Udorthents are very shallow to deep over limestone bedrock. They consist of unconsolidated or heterogeneous geologic material removed during the excavation of ditches, canals, lakes, ponds, and quarries. The material commonly is piled along banks or in scattered areas. Slopes are 15 to 60 percent. About 65 percent of this map unit is Udorthents, and about 20 percent is water. Included in this map unit are small areas of a Udorthents-Urban land complex, which makes up less than 15 percent of any one area.

Typically, the Udorthents consist of mixed light gray and white limestone gravel and loamy carbonatic material, which extend to a depth of 80 inches or more.

The water table in areas of the Udorthents is within the limestone bedrock. Permeability is moderate.

Weeds and native grasses have become established in some areas. Other areas support little or no vegetation.

This map unit is not used as cropland. In many areas it is used as a source of road-building material and as a source of fill for new homesites, golf courses, and other purposes.

No capability classification is assigned.

10—Udorthents, limestone substratum-Urban land complex.

About 40 to 70 percent of this map unit consists of Udorthents in open areas, and 25 to 60 percent consists of Urban land, or areas covered by concrete and buildings. The Udorthents and Urban land occur as areas so intermixed or so small that mapping them separately is impractical. Slopes are 0 to 2 percent.

The Udorthents are in areas of lawns, vacant lots, parks, and playgrounds. The Urban land consists of streets, driveways, sidewalks, parking lots, buildings, and other structures in areas where the soil is covered and cannot be readily observed.

Typically, the Udorthents consist of fill material that is light gray and white extremely stony loam about 55 inches thick. The fill material is underlain by hard, porous limestone bedrock.

Included in this map unit are small areas of Krome and Cardsound soils and areas in which the fill material is less than 8 or more than 80 inches thick. Also included are areas where a few inches of marl is between the fill and the limestone and areas where 2 to 4 inches of marl overlies the stony fill. Included soils make up 10 percent or less of any one area. Cardsound and Krome soils are in positions on the landscape similar to those of the Udorthents. They are very shallow over limestone bedrock.

The water table in areas of the Udorthents is within the limestone bedrock. Permeability is moderate in the stony fill material.

This map unit is not used as cropland. The Udorthents consist mostly of stony limestone fragments used as fill material in low areas. The fill material improves the suitability of the low areas for building site development or other urban uses. If lawns and ornamental plants are to be established and maintained on the soils in this map unit, a layer of good topsoil about 6 inches thick is needed. Proper watering and regular applications of fertilizer also are needed.

No capability classification is assigned.

11—Udorthents, marl substratum-Urban land complex.

About 40 to 70 percent of this map unit consists of Udorthents in open areas, and 25 to 60 percent consists of Urban land, or areas covered by concrete and buildings. The Udorthents consist of heterogeneous geologic material that has been excavated and spread. The Udorthents and Urban land occur as areas so intermixed or so small that mapping them separately is impractical. Slopes are 0 to 2 percent.

The Udorthents are in areas of lawns, vacant lots, parks, and playgrounds. The Urban land consists of streets, driveways, sidewalks, parking lots, buildings, and other structures in areas where the soil is covered and cannot be readily observed.

Typically, the upper 12 inches of the Udorthents is fill material that is light gray very gravelly loam. The next 29 inches is brown gravelly sandy loam. Below this to a depth of 60 inches or more is natural soil, which is predominantly marl that has a texture of silt loam. Hard, porous limestone bedrock is at a depth of 60 inches or more.

Included in this map unit are small areas in which the fill material is less than 40 or more than 80 inches thick. Also included are areas where the fill material directly overlies limestone bedrock or muck. Included soils make up 10 percent or less of any one area.

Depth to the water table in the Udorthents is dominantly more than 40 inches, but it varies, depending on the thickness of the fill material. Permeability is moderately slow or moderate in the layers of marl.

This map unit is not used as cropland. The Udorthents consist of gravelly limestone fragments used as fill material in low areas of marl. The fill material improves the suitability of the low areas for building site development or other urban uses. If lawns and ornamental plants are to be established and maintained on the soils in this map unit, a layer of good topsoil about 6 inches thick is needed. Proper watering and regular applications of fertilizer also are needed.

No capability classification is assigned.

12—Perrine marl.

This moderately deep, nearly level, very poorly drained soil is in broad, low coastal marshes and sloughs and in small depressional areas. It is ponded for 9 to 12 months in most years. Individual areas are broad and irregularly shaped and range from 6 to 600 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Perrine marl, Perrine and similar soils make up 82 to 99 percent of the mapped areas.

Typically, the surface layer is about 4 inches of grayish brown marl that has a texture of silt loam. The underlying material, to a depth of about 29 inches, is marl that has a texture of silt loam, is mottled in shades of light brownish gray and light gray, and has common or many very dark grayish brown pockets and streaks. Soft, porous limestone bedrock is at a depth of about 29 inches.

Included in mapping are soils that are similar to Perrine marl, but have limestone bedrock at a depth of less than 20 or more than 40 inches and may have continuous layers of muck more than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Dania, Lauderhill, and Tamiami soils and small areas of Udorthents. Dissimilar soils make 1 to 18 percent of most mapped areas. Dania, Lauderhill, and Tamiami soils are in positions on the landscape similar to those of the Perrine soil. They have an organic surface layer. Udorthents are in the slightly higher areas of mineral fill material.

The water table in the Perrine soil remains at or above the surface for 2 to 6 months in most years and is within a depth of 12 inches for the rest of the year. Permeability is moderately slow.

The natural vegetation consists of sawgrass, cattail, primrose willow, smooth cordgrass, buttonbush, boneset, gulf muhly, broom sedge, and a variety of water-tolerant weeds, ferns, grasses, and sedges. Calcium carbonate crusted periphyton covers the surface and bases of plants in many areas. Exotic tree species, including Australian pine, Brazilian pepper, and melaleuca, have become established in some areas. Areas of this soil provide excellent habitat for wading birds, aquatic reptiles, small crustaceans, and other kinds of wetland wildlife.

This soil is poorly suited to cultivated crops and the production of nursery plants because of the ponding. In areas nearest to the coast, the soil is too saline for most cultivated crops and ornamental plants. If a complete water-control system that can remove excess water rapidly were installed and carefully maintained, many areas of the soil would be well suited to a variety of cultivated crops, ornamental plants, and pasture. Bedding is needed if ornamental plants are grown. Because of a high pH, some micronutrients may not be available to certain crops. Boron toxicity may affect some crops.

This soil is unsuited to the production of citrus, mangos, and avocados because of the ponding.

This soil generally is not used as rangeland or forest land. It is in the Sawgrass Marsh and Freshwater Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development, mainly because of the ponding and the depth to bedrock. Extensive water-control measures and large amounts of suitable fill material are needed to overcome these limitations.

The capability subclass is VIIw.

13—Biscayne marl.

This very shallow or shallow, nearly level, very poorly drained soil is on broad, low coastal flats, in freshwater marshes and sloughs, and in small depressional areas. It is ponded for 2 to 4 months in most years. Individual areas are broad and irregularly shaped and range from 6 to 200 acres in size. Slopes are smooth or slightly concave and are less than 2 percent.

On 95 percent of the acreage mapped as Biscayne marl, Biscayne and similar soils make up 82 to 99 percent of the mapped areas.

Typically, the surface layer is about 5 inches of gray marl that has a texture of silt loam. Below this, to a depth of about 17 inches, is gray or grayish brown marl that has a texture of silt loam. Hard, porous limestone bedrock is at a depth of about 17 inches.

Included in mapping are soils that are similar to Biscayne marl, but have more than 15 percent gravel, have been drained, are less than 1 inch deep over bedrock, have continuous organic layers that are more than 8 inches thick, but make up less than half of the total soil depth, or are 20 to 40 inches deep over bedrock.

Dissimilar soils that are included with this soil in mapping occur as small areas of Dania, Hallandale, Lauderhill, Pennsuco, and Tamiami soils. Dissimilar soils make up 1 to 18 percent of most mapped areas. Dania, Lauderhill, and Tamiami soils are in positions on the landscape similar to those of the Biscayne soil. They have an organic surface layer. Hallandale soils are in the higher positions on the landscape. They do not have marl in the surface layer. Pennsuco soils are in the slightly higher positions on the landscape. They are deep or very deep over limestone bedrock.

The water table in the Biscayne soil remains at or above the surface for 2 to 4 months during most years, receding to as deep as 20 inches during dry periods. Permeability is moderate.

The natural vegetation consists of sawgrass, cattail, primrose willow, smooth cordgrass, buttonbush, boneset, gulf muhly, broom sedge, and a variety of water-tolerant sedges and grasses. Calcium carbonate crusted periphyton covers the surface and bases of plants in many areas. Exotic tree species, including Australian pine, Brazilian pepper, and melaleuca, have become established in some areas. Areas of this soil provide habitat for wading birds, aquatic reptiles, small crustaceans, and other kinds of wetland wildlife.

This soil is poorly suited to cultivated crops, nursery plants, and pasture because of the ponding. In areas nearest to the coast, the soil is too saline for most cultivated crops and ornamental nursery plants. If a complete water-control system, including canals and field ditches, were installed and carefully maintained, many areas of the soil would be well suited to a variety of vegetable crops, ornamental nursery plants, and pasture.

This soil is unsuited to the production of citrus, mangos, and avocados because of the ponding.

This soil is not used as rangeland or forest land. It is in the Sawgrass Marsh and Freshwater Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding and the depth to bedrock. Extensive water-control measures and large amounts of suitable fill material are needed to overcome these limitations.

The capability subclass is VIIw.

14—Dania muck, depressional.

This shallow, nearly level, very poorly drained soil is in poorly defined drainageways and adjacent to deeper organic soils within sawgrass marshes. It is ponded for 9 to 12 months in most years. Individual areas are long and are narrow or broad. They range from 6 to 3,000 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Dania muck, depressional, Dania and similar soils make up 83 to 99 percent of the mapped areas.

Typically, the surface layer is black muck about 15 inches thick. Soft, porous limestone bedrock is at a depth of about 15 inches.

Included in mapping are soils that are similar to Dania muck, depressional, but have limestone bedrock at a depth of more than 20 or less than 8 inches or have a layer of periphyton or marl in the upper 1 to 8 inches.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne soils and small areas of Udorthents. Dissimilar soils make up 1 to 17 percent of most mapped areas. Biscayne soils are in positions on the landscape similar to those of the Dania soil. They have a surface layer of marl. Udorthents are in the slightly higher areas of mineral fill material.

Under natural conditions, the Dania soil usually is ponded nearly throughout of the year. The water table is within 10 inches of the surface for the rest of the year. Permeability is rapid in the organic material. Oxidation decreases the amount of organic material each year. If drained, the organic material initially shrinks to about half the original thickness and then subsides further as a result of compaction and oxidation. These losses are most rapid during the first 2 years. The lower the water table, the more rapid the loss. The marl does not subside.

Most areas support native vegetation, which consists of sawgrass and cattail. Melaleuca trees have invaded some areas. Areas of this soil provide cover for deer and excellent habitat for wading birds and other kinds of wetland wildlife.

Under natural conditions, this soil generally is not suited to cultivation. If water is controlled through a system of dikes, ditches, and pumps, however, the soil is well suited to most winter vegetable crops. A well designed and maintained water-control system can remove excess water during periods when crops are growing on the soil and can keep the soil saturated at all other times. Keeping the soil saturated minimizes oxidation. Cover crops and crop residue should be left on the surface or plowed under. Fertilizer should be applied according to the needs of the crop. In some areas the soil is used as improved pasture. Improved bahiagrass and pangolagrass are suitable.

This soil is not suited to the production of citrus, mangos, or avocados because of the wetness.

This soil is not used as native rangeland or forest land. It is in the Sawgrass Marsh ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding, excess humus, low strength, and the depth to bedrock. Water-control measures are needed to prevent ponding. The organic material should be removed, and suitable backfill material should be provided. Sealing or lining sewage lagoons and trench sanitary landfills with impervious soil material helps to prevent seepage. Mounding may be needed on sites for septic tank absorption fields.

The capability subclass is VIIw.

15—Urban land.

This map unit is in areas where more than 85 percent of the surface is covered by shopping centers, parking lots, streets, sidewalks, airports, large buildings, houses, and other structures. The natural soil cannot be observed. The soils in open areas, mostly lawns, vacant lots, playgrounds, and parks, are mainly Udorthents. These soils generally have been altered by land grading and shaping or have been covered with about 18 inches of extremely stony, loamy fill material. Areas of these soils are so small that mapping them separately is impractical.

No capability classification is assigned.

16—Biscayne marl, drained.

This very shallow or shallow, nearly level, poorly drained soil is on broad, low coastal flats and in transverse glades that extend into the Pineland Ridge. Individual areas are broad and irregularly shaped or are rectangular. They range from 6 to 3,000 acres in size. Slopes are smooth or concave and are less than 2 percent.

On 95 percent of the acreage mapped as Biscayne marl, drained, Biscayne and similar soils make up 80 to 99 percent of the mapped areas.

Typically, the surface layer is about 5 inches of gray marl that has a texture of silt loam. The underlying layer, to a depth of about 15 inches, is gray and light gray marl that has a texture of silt loam. Hard, porous limestone bedrock is at a depth of about 15 inches. It has scattered small solution holes containing very dark gray, noncalcareous mucky silt loam.

Included in mapping are soils that are similar to Biscayne marl, drained, but have more than 15 percent gravel, by volume, are ponded and may have a continuous layer or layers of organic material that are more than 8 inches thick, but make up less than half of the total soil depth, or have limestone bedrock at a depth of more than 20 or less than 40 inches.

Dissimilar soils that are included with this soil in mapping occur as small areas of Chekika, Dania, Lauderhill, and Pennsuco soils. Also included are areas of Rock outcrop. Dissimilar inclusions make up about 1 to 20 percent of most mapped areas. Chekika soils are in the slightly higher positions on the landscape. They have more than 35 percent gravel in the surface layer. Dania and Lauderhill soils are in the slightly lower positions on the landscape. They have an organic surface layer. Pennsuco soils are in positions on the landscape similar to those of the Biscayne soil. They are deep or very deep over limestone bedrock.

The water table in the Biscayne soil remains within 10 inches of the surface for 4 to 6 months during most years, receding to as deep as 20 inches during dry periods. Permeability is moderate.

All areas have been drained and cultivated at some time in the past. The native vegetation no longer remains. Abandoned fields quickly become overgrown with thick stands of Brazilian pepper, leatherleaf fern, and a variety of shrubs, broadleaf weeds, and grasses.

A water-control system has been installed in most areas. If the water-control system is properly maintained, this soil is well suited to a variety of shallow-rooted cultivated crops. Much of the cultivated acreage is used for corn, potatoes, snap beans, sorghum, malanga, or ornamental trees and shrubs. Land grading and smoothing fill in the small depressions that are common in areas of this soil and thus improve surface drainage and permit more efficient use of farm equipment and more uniform application of irrigation water. Bedding is necessary if ornamental plants or root crops are grown. Returning crop residue to the soil or regularly adding other organic material improves fertility and tilth and increases the rate of water intake. Prolonged cultivation with heavy equipment can result in the formation of a tillage pan. Subsoiling during dry periods helps to break up the pan and thus permits deeper root penetration. Disking during wet periods often results in cloddiness. Important management practices include preparing a good seedbed, applying fertilizer according to the results of soil tests and the needs of the crop, and controlling weeds and brush. Because of a high pH, some micronutrients may not be available to certain crops. Boron toxicity may affect some crops.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor. Deferred grazing during wet periods helps to prevent compaction of the soil.

This soil is poorly suited to the production of citrus and mangos because of the wetness. It is unsuited to the production of avocados.

This soil generally is not used as rangeland or forest land. Under natural conditions, it is in the Freshwater Marsh and Sawgrass Marsh ecological plant communities.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material are needed to overcome these limitations.

The capability subclass is IIIw.

18—Tamiami muck, depressional.

This moderately deep or deep, nearly level, very poorly drained soil is in freshwater swamps and marshes. It is ponded for 9 to 12 months in most years. Individual areas are broad and irregularly shaped and range from 50 to 1,000 acres in size. Slopes are smooth or slightly concave and are less than 2 percent.

On 95 percent of the acreage mapped as Tamiami muck, depressional, Tamiami and similar soils make up 83 to 99 percent of the mapped areas.

Typically, the surface layer is black muck about 4 inches thick. The next 8 inches is gray marl that has a texture of silt loam. Below this, to a depth of about 31 inches, is very dark gray muck. Hard, porous limestone bedrock is at a depth of about 31 inches.

Included in mapping are soils that are similar to Tamiami muck, depressional, but have layers of marl less than 6 inches thick or consist of muck that is more than 51 inches deep over limestone.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne soils and areas where the layers of marl make up more than half of the total soil depth. Dissimilar soils make up 1 to 17 percent of most mapped areas. Biscayne soils are in positions on the landscape similar to those of the Tamiami soil. They consist of marl and are shallow or very shallow over limestone.

Under natural conditions, the Tamiami soil is ponded for 9 to 12 months during most years. The water table is within 10 inches of the surface for the rest of the year. Permeability is moderate. The organic layers are subject to oxidation, which decreases the amount of organic material each year. If drained, the organic material initially shrinks to about half the original thickness and then subsides further as a result of compaction and oxidation. These losses are most rapid during the first 2 years. If drained, the soil continues to subside at a rate of about 1 inch per year. The lower the water table, the more rapid the loss.

Most areas support natural vegetation, which consists of cattail, sawgrass, gulf muhly, star rush, milkwort, and sedges. Some areas that have been drained or disturbed may be dominated by Brazilian pepper and melaleuca. Areas of this soil provide cover for deer and excellent habitat for wading birds and other kinds of wetland wildlife.

Under natural conditions, this soil generally is not suited to cultivation. If water is controlled through a system of dikes, ditches, and pumps, however, the soil is well suited to most winter vegetable crops. A well designed and maintained water-control system can remove excess water during periods when crops are growing on the soil and can keep the soil saturated at all other times. Keeping the soil saturated minimizes oxidation. Important management practices include good seedbed preparation and a suitable crop rotation. Cover crops and crop residue should be left on the surface or plowed under. Fertilizer should be applied according to the needs of the crop.

This soil is not suited to the production of citrus, avocados, or pine trees because of the wetness.

This soil is not used as rangeland or forest land. It is in the Freshwater Marsh ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding, excess humus, low strength, and the depth to bedrock. Water-control measures are needed to prevent ponding. The organic material should be removed, and suitable backfill material should be provided. Sealing or lining sewage lagoons and trench sanitary landfills with impervious soil material helps to prevent seepage. The sides of shallow excavations should be shored. Mounding may be needed on sites for septic tank absorption fields.

The capability subclass is VIIw.

20—Cardsound-Rock outcrop complex.

This map unit consists of a Cardsound soil intermingled with areas of Rock outcrop. The Cardsound soil and Rock outcrop occur as areas so intermixed or so small that mapping them separately is impractical. Individual areas are irregularly shaped or rectangular and range from 5 to 100 acres in size. Slopes are smooth and range from 0 to 2 percent.

About 54 percent of this map unit is Cardsound and similar soils, and 38 percent is Rock outcrop.

Typically, the surface layer of the Cardsound soil is dark yellowish brown silty clay loam about 4 inches thick. Hard, porous limestone bedrock is at a depth of about 4 inches. It has solution holes that contain silty clay loam or silty clay.

Included in mapping are soils that are similar to the Cardsound soil, but are darker or are very gravelly and loamy. Also included are areas where a mat of pine needles overlies the limestone bedrock.

Dissimilar soils that are included with the Cardsound soil in mapping occur as small areas of Matecumbe soils and small areas of Udorthents. Dissimilar soils make up less than 10 percent of most mapped areas. Matecumbe soils are in the slightly higher positions on the landscape. They have an organic surface layer. Udorthents are in the slightly higher areas of mineral fill material.

Under natural conditions, the water table in areas of the Cardsound soil is within the limestone bedrock. It is at a depth of 60 and 72 inches in most years. Permeability is moderately slow.

Under natural conditions, this map unit is not used for fruit or vegetable crops or as rangeland. It is in the Everglades Flatwoods ecological plant community.

This map unit is severely limited as a site for urban uses because of the depth to bedrock. Local construction methods generally can overcome this limitation. The map unit commonly is used for urban development.

The Cardsound soil is in capability subclass IVw. The Rock outcrop is not assigned a capability classification.

22—Opalocka-Rock outcrop complex.

This map unit consists mainly of a Opalocka soil intermingled with areas of Rock outcrop. The Opalocka soil and Rock outcrop occur as areas so intermixed or so small that mapping them separately is impractical. Individual areas range from 5 to 100 acres in size. Slopes are smooth and range from 0 to 2 percent.

On 95 percent of the acreage mapped as Opalocka-Rock outcrop complex, Opalocka and similar soils and Rock outcrop make up 98 to 99 percent of the mapped areas. About 60 percent of this map unit is Opalocka and similar soils, and 40 percent is Rock outcrop.

Typically, the surface layer of the Opalocka soil is brown sand about 6 inches thick. Hard, porous limestone bedrock is at a depth of about 6 inches. It has solution holes that contain sand. Sandy loam, sandy clay loam, or sandy clay is next to the limestone, lining the bottom and sides of some solution holes.

Dissimilar soils that are included with the Opalocka soil in mapping occur as small areas of Krome soils. These soils make up about 1 to 2 percent of most mapped areas. They are in positions on the landscape similar to those of the Opalocka soil. They have a gravelly surface layer.

Permeability is very rapid in the Opalocka soil. The water table is always within the limestone bedrock. It is at a depth of 60 to 72 inches.

Under natural conditions, this map unit is not used for fruit or vegetable crops. If cleared and rock-plowed, however, the map unit becomes Krome very gravelly loam, which commonly is used for crop production.

This map unit is not used as rangeland. It is in the Everglades Flatwoods ecological plant community.

This map unit is severely limited as a site for urban uses because of the depth to bedrock. Local construction methods generally can overcome this limitation. The map unit commonly is used for urban development.

The Opalocka soil is in capability subclass VIs. The Rock outcrop is not assigned a capability classification.

23—Chekika very gravelly loam.

This very shallow, nearly level, somewhat poorly drained soil is in transitional areas between the Miami Ridge and the Everglades. Individual areas are broad and irregularly shaped and range from 6 to 100 acres in size. Slopes are smooth and range from 0 to 2 percent.

On 95 percent of the acreage mapped as Chekika very gravelly loam, Chekika and similar soils make up 77 to 99 percent of the mapped areas.

Typically, the surface layer is dark grayish brown very gravelly loam about 5 inches thick. Hard, porous limestone bedrock is at a depth of about 5 inches. Solution holes in the limestone extend to a depth of about 9 inches. They contain silt loam or silty clay loam.

Included in mapping are soils that are similar to the Chekika soil, but contain less than 35 percent or more than 60 percent gravel.

Dissimilar soils that are included with this soil in mapping occur as small areas of Biscayne, Krome, Matecumbe, and Opalocka soils. Also included are areas of Rock outcrop. Dissimilar inclusions make up 1 to 23 percent of most mapped areas. Biscayne soils are on low flats and are poorly drained. Krome soils are on low hills and are moderately well drained. Matecumbe soils are on hammocks. They have an organic surface layer. Opalocka soils are in the slightly higher positions on the landscape. They have a sandy surface layer.

The water table in areas of the Chekika soil is within the limestone bedrock. It is at a depth of 12 to 36 inches in most years. Permeability is moderate.

All areas have been rock-plowed and used for vegetable crops at some time in the past. This soil is suitable for a wide variety of fruit and vegetable crops, but special management is needed. This management includes yearly rock-plowing, bedding, regularly adding fertilizer, and irrigating during the winter growing season. Because of a favorable climate, the water available for irrigation, and the demand by northern markets, this high level of management is practical.

Figure 5.—Rock-plowing in an area of Chekika very gravelly loam. (gif, 72 KB) This measure helps to prepare the soil for planting.

This soil is suitable for the production of fruit and citrus, but this production requires trenching, drilling, or blasting into the limestone. Regular applications of fertilizer and irrigation water also are needed.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to maintain plant vigor.

This soil is not used as rangeland or forest land. It is in the Everglades Flatwoods ecological plant community.

This soil is severely limited as a site for urban uses because of the depth to bedrock and the wetness. Water-control measures are needed to prevent excessive wetness. Mounding may be needed on sites for septic tank absorption fields and buildings.

The capability subclass is IIIw.

24—Matecumbe muck.

This very shallow, moderately well drained soil is on small tropical hardwood hammocks on the Miami Ridge and in the Everglades. It is occasionally flooded. Individual areas range from 50 to 40 acres in size. Slopes are smooth or slightly convex and are less than 2 percent.

On 80 percent of the acreage mapped as Matecumbe muck, Matecumbe and similar soils make up 80 to 100 percent of the mapped areas.

Typically, the surface layer is a thin bed of leaf litter, twigs, and branches in varying stages of decomposition. Soft limestone bedrock is at a depth of about 3 inches. Solution holes in the limestone extend to a depth of about 40 inches. They contain silty clay loam, silty clay, or muck. Sinkholes vary in size and depth.

Dissimilar soils that are included with this soil in mapping occur as small areas of Cardsound and Lauderhill soils. Also included are areas of Rock outcrop. Dissimilar inclusions make up 20 percent or less of most mapped areas. Cardsound soils are in the slightly higher positions on the landscape and are well drained. Lauderhill soils are in the lower positions on the landscape. They are moderately deep over limestone bedrock.

The water table in areas of the Matecumbe soil is within the limestone bedrock. It is at a depth of 18 to 36 inches in most years. Permeability is rapid.

This soil is not suited to pasture, vegetable crops, or the production of fruit or citrus because of the depth to bedrock. Clearing and rock-plowing cause rapid depletion of this shallow, organic soil. If the soil is cleared and rock-plowed, it generally is included in the surrounding map unit.

This soil is not used as rangeland. It is in the Tropical Hammocks ecological plant community.

This soil is well suited to wildlife habitat. It provides habitat for many endangered and threatened species.

This soil is severely limited as a site for urban uses because of the depth to bedrock.

The capability subclass is VIIs.

25—Biscayne-Rock outcrop complex.

This map unit consists mainly of Biscayne marl intermingled with areas of Rock outcrop. The Biscayne soil and Rock outcrop occur as areas so intermixed or so small that mapping them separately is impractical. Individual areas are broad and irregularly shaped and range from 6 to 500 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Biscayne-Rock outcrop complex, Biscayne and similar soils and Rock outcrop make up 86 to 97 percent of the mapped areas. About 55 percent of this map unit is Biscayne and similar soils, and 42 percent is Rock outcrop.

Typically, the surface layer of the Biscayne soil is about 4 inches of grayish brown marl that has a texture of silt loam. Hard, porous limestone bedrock is at a depth of about 4 inches. It has solution holes that contain silty clay or clay.

Included in mapping are soils that are similar to the Biscayne soil but are gravelly.

Dissimilar soils that are included with the Biscayne soil in mapping occur as small areas of Chekika, Dania, and Krome soils. Dissimilar soils make up 3 to 14 percent of most mapped areas. Chekika and Krome soils have coarse fragments in the surface layer. Chekika soils are in the higher positions on the landscape. Krome soils are moderately well drained. Dania soils are in concave areas. They are organic.

The water table in the Biscayne soil is below the surface for the majority of most years, but the soil can be briefly ponded during extremely wet periods. Permeability is moderate.

Most areas support natural vegetation, which consists of scattered cabbage-palm and melaleuca. The understory includes South Florida bluestem, sawgrass, gulf muhly, boneset, milkwort, Carolina willow, and various water-tolerant grasses. Dense stands of natural vegetation are in rock cavities or solution holes.

Under natural conditions, this map unit is not used for fruit or vegetable crops, ornamental plants, or pasture. If rock-plowed, the map unit becomes either Biscayne gravelly marl or Chekika very gravelly loam, depending on the depth to limestone bedrock and the amount and type of material incorporated from the solution holes.

This map unit is not used as rangeland or forest land. It is in the Freshwater Marsh ecological plant community.

This map unit is severely limited as a site for urban uses and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material are needed to overcome these limitations.

The Biscayne soil is in capability subclass IVw. The Rock outcrop is not assigned a capability classification.

26—Perrine marl, tidal.

This moderately deep, nearly level, very poorly drained soil is in tidal mangrove swamps near the coast in southeastern Florida and is subject to tidal flooding. Individual areas range from 6 to 100 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Perrine marl, tidal, Perrine and similar soils make up 82 to 99 percent of the mapped areas.

Typically, the surface layer is about 12 inches of dark brown marl that has a texture of silt loam. Below this, to a depth of about 26 inches, is dark gray marl that has a texture of silt loam. Soft, porous limestone bedrock is at a depth of about 26 inches.

Included in mapping are soils that are similar to Perrine marl, tidal, but have limestone bedrock at a depth of more than 40 inches or are nonsaline and in the upper 40 inches may have layers of organic material that are more than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Lauderhill and Terra Ceia soils and small areas of organic soils having layers of marl that are more than 4 inches thick but make up less than half of the total soil depth. Dissimilar soils make up 1 to 18 percent of most mapped areas. Lauderhill soils are in shallow depressions. They are organic. Terra Ceia soils are in positions on the landscape similar to those of the Perrine soil. They are organic to a depth of more than 51 inches.

Under natural conditions, the Perrine soil remains saturated and the water table fluctuates with the tides. The soil is moderately saline or saline. Permeability is moderately slow.

The natural vegetation consists of scattered and stunted red mangrove. Areas of this soil provide excellent habitat for birds and small marine crustaceans.

Because of tidal flooding and salinity, this soil is not suited to cropland, groves, or improved pasture.

This soil generally is not used as rangeland. It is in the Mangrove Swamp ecological plant community.

This soil is severely limited as a site for all urban uses because of the tidal flooding, the depth to bedrock, and the wetness.

This soil is in mangrove swamps, which are unique and biologically productive areas that are very important to many species of fish and wildlife. Many sport and commercial finfish, shellfish, and other crustaceans use these areas as spawning grounds. Mangrove swamps along coastal areas and in estuaries also serve as protective barriers against excessive wave action during tropical storms.

The capability subclass is VIIIw.

28—Demory-Rock outcrop complex.

This map unit consists of a nearly level, poorly drained, very shallow Demory soil intermingled with areas of Rock outcrop. The unit is in transitional areas between organic soils and poorly drained, sandy soils. The Demory soil and Rock outcrop occur as areas so intermingled or so small that mapping them separately is impractical. Individual areas range from 5 to 500 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Demory-Rock outcrop complex, Demory and similar soils and Rock outcrop make up 86 to 99 percent of the mapped areas. About 70 percent of this map unit is Demory and similar soils, and 25 percent is Rock outcrop.

Typically, the surface layer of the Demory soil is about 7 inches thick. The upper 4 inches is very dark brown sandy clay loam, and the lower 3 inches in black sandy clay loam. Below this is about 3 inches of dark brown sandy loam. Hard, porous limestone bedrock is at a depth of about 10 inches.

Dissimilar soils that are included with the Demory soil in mapping occur as small areas of Biscayne, Chekika, and Dania soils. Dissimilar soils make up 1 to 14 percent of most mapped areas. Biscayne soils are in the higher positions on the landscape. They have a surface layer of marl. Chekika soils are somewhat poorly drained. They have coarse fragments in the surface layer. Dania soils are organic.

The water table in the Demory soil is below the surface for the majority of most years. The soil is flooded on rare occasions during periods of high rainfall. Permeability is moderately slow.

Most areas support natural vegetation. Water-tolerant vegetation, such as South Florida bluestem, sawgrass, gulf muhly, cabbage-palm, and willow, dominates the landscape.

This map unit is not used as rangeland or forest land. It is in the Freshwater Marsh ecological plant community.

This map unit is severely limited as a site for urban development and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material are needed to overcome these limitations.

The Demory soil is in capability subclass VIIs. The Rock outcrop is not assigned a capability classification.

30—Pahokee muck, depressional.

This moderately deep, nearly level, very poorly drained soil is in freshwater swamps and marshes. It is ponded for 6 to 9 months in most years. Individual areas range from 30 to 1,000 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Pahokee muck, depressional, Pahokee and similar soils make up 99 percent of the mapped areas.

Typically, the soil is muck to a depth of about 46 inches. The upper 11 inches is black, and the lower 35 inches is very dark brown. Hard, porous limestone bedrock is at a depth of about 46 inches.

Included in mapping are soils that are similar to Pahokee muck but are less than 36 or more than 51 inches deep over limestone bedrock or have small, discontinuous lenses or pockets of marl within a depth of 30 inches.

Dissimilar soils that are included with this soil in mapping occur as small areas of Dania soils and small areas of soils that are more than 80 inches deep over limestone bedrock. Dissimilar soils make up 1 percent or less of most mapped areas. Dania soils are very shallow or shallow over limestone bedrock.

Under natural conditions, the Pahokee soil is ponded for 9 to 12 months during most years. The water table is within 10 inches of the surface for the rest of the year. Permeability is rapid. This soil is subject to oxidation, which decreases the amount of the organic material each year. If drained, the organic material initially shrinks to about half the original thickness and then subsides further as a result of compaction and oxidation. These losses are most rapid during the first 2 years. If drained, the soil continues to subside at a rate of about 1 inch per year. The lower the water table, the more rapid the loss.

Most areas support natural vegetation, which consists of cattail and sawgrass. Areas that have been drained or disturbed, however, may be dominated by Brazilian pepper and melaleuca. Areas of this soil provide cover for deer and excellent habitat for wading birds and other kinds of wetland wildlife.

Under natural conditions, this soil generally is not suited to cultivation. If water is controlled through a system of dikes, ditches, and pumps, however, the soil is well suited to most winter vegetable crops. A well designed and maintained water-control system can remove excess water during periods when crops are growing on the soil and can keep the soil saturated at all other times. Keeping the soil saturated minimizes oxidation. Important management practices include good seedbed preparation and a suitable crop rotation. Cover crops and crop residue should be left on the surface or plowed under. Fertilizer should be applied according to the needs of the crop.

This soil is not suited to the production of citrus, avocados, or pine trees because of the wetness.

This soil is not used as rangeland. It is in the Freshwater Marsh ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding, excess humus, low strength, and the depth to bedrock. Water-control measures are needed to prevent ponding. The organic material should be removed, and suitable backfill material should be provided. Sealing or lining sewage lagoons and trench sanitary landfills with impervious soil material helps to prevent seepage. The sides of shallow excavations should be shored. Mounding may be needed on sites for septic tank absorption fields.

The capability subclass is VIIw.

31—Pennsuco marl, tidal.

This deep, nearly level, very poorly drained soil is in tidal mangrove swamps near the coast in southeastern Florida and is subject to tidal flooding. Individual areas range from 6 to 100 acres in size. Slopes are smooth or concave and are less than 1 percent.

On 95 percent of the acreage mapped as Pennsuco marl, tidal, Pennsuco and similar soils make up 75 to 99 percent of the mapped areas.

Typically, the surface layer is about 51 inches of light gray marl that has a texture of silt loam. Soft, porous limestone bedrock is at a depth of about 51 inches.

Included in mapping are soils that are similar to Pennsuco marl, tidal, but have limestone bedrock at a depth of less than 40 or more than 80 inches or in the upper 40 inches have layers of organic material that are more than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Lauderhill and Terra Ceia soils and small areas of organic soils having layers of marl that are more than 4 inches thick but make up less than half of the total soil depth. Dissimilar soils make up 1 to 25 percent of most mapped areas. Lauderhill soils are in shallow depressions. They are organic. Terra Ceia soils are in positions on the landscape similar to those of the Pennsuco soil. They are organic to a depth of more than 51 inches.

Under natural conditions, this soil remains saturated and the water table fluctuates with the tides. The soil is moderately saline or saline. Permeability is moderately slow.

The natural vegetation is scattered and stunted red mangrove. Areas of this soil provide excellent habitat for birds and small marine crustaceans.

Because of tidal flooding and salinity, this soil is not suited to cropland, groves, or improved pasture. It generally is not used as rangeland. It is in the Mangrove Swamp ecological plant community.

This soil is severely limited as a site for all urban uses because of tidal flooding and ponding.

This soil is in mangrove swamps, which are unique and biologically productive areas that are very important to many species of fish and wildlife. Many sport and commercial finfish, shellfish, and other crustaceans use these areas as spawning grounds. Mangrove swamps along coastal areas and in estuaries also serve as protective barriers against excessive wave action during tropical storms.

The capability subclass is VIIIw.

32—Terra Ceia muck, tidal.

This deep, level, very poorly drained soil is in saltwater swamps and marshes and is subject to tidal flooding. Individual areas are long and narrow and range from 100 to 500 acres in size. Slopes are less than 1 percent.

On 95 percent of the acreage mapped as Terra Ceia muck, tidal, Terra Ceia and similar soils make up 82 to 99 percent of the mapped areas.

Typically, the soil is muck to a depth of 80 inches or more. The upper 8 inches is very dark brown, and the lower 72 inches or more is black.

Included in mapping are soils that are similar to Terra Ceia muck, tidal, but are less than 51 inches deep over limestone bedrock or have discontinuous lenses or pockets of marl within the control section.

Dissimilar soils that are included with this soil in mapping occur as small areas of Lauderhill soils and small areas of the tidal Pennsuco and Perrine soils. Dissimilar soils make up 1 to 18 percent of most mapped areas. Lauderhill soils are in positions on the landscape similar to those of the Terra Ceia soil. They are moderately deep over limestone bedrock. Pennsuco and Perrine soils have a surface layer and subsurface layer of marl.

Under natural conditions, the Terra Ceia soil remains saturated. Fluctuating tides cover the surface twice daily. Permeability is rapid.

The natural vegetation consists mainly of red and black mangrove. White mangrove grows in some areas.

Because of tidal flooding, this soil is not suited to cropland, citrus, or improved pasture.

This soil is not used as rangeland. It is in the Mangrove Swamp ecological plant community.

This soil is not suited to urban uses because of tidal flooding and low strength.

This soil is in mangrove swamps, which are unique and biologically productive areas that are very important to many species of fish and wildlife. Many sport and commercial finfish, shellfish, and other crustaceans use these areas as spawning grounds. Mangrove swamps in estuaries also serve as protective barriers against excessive wave action during tropical storms.

The capability subclass is VIIIw.

33—Plantation muck.

This moderately deep, nearly level, very poorly drained soil is in transitional areas between the organic soils of the Everglades and the sandy soils of the Everglades Flatwoods. Individual areas range from 50 to 600 acres in size. Slopes are less than 1 percent.

On 95 percent of the acreage mapped as Plantation muck, Plantation and similar soils make up 90 to 99 percent of the mapped areas.

Typically, the surface layer is muck about 14 inches thick. The upper 6 inches is black, and the lower 8 inches is dark reddish brown. The underlying material extends to a depth of about 30 inches. It is very dark grayish brown fine sand in the upper 7 inches, light gray fine sand in the next 7 inches, brown very gravelly fine sand in the lower 2 inches. Soft, porous limestone bedrock is at a depth of about 30 inches.

Included in mapping are soils that are similar to Plantation muck, but have a surface layer of muck that is less than 8 or more than 16 inches thick or are less than 20 or more than 40 inches deep over limestone bedrock.

Dissimilar soils that are included with this soil in mapping occur as small areas of Lauderhill soils and small areas of Udorthents. Dissimilar soils make up 1 to 10 percent of most mapped areas. Lauderhill soils are in the lower positions on the landscape. They are organic to a depth of more than 16 inches. Udorthents are in the slightly higher areas of mineral fill material.

Under natural conditions, the Plantation soil has water above the surface for 1 to 3 months during most years. During most years the water table is at or near the surface for 4 to more than 6 months. It may recede to as deep as 20 inches during the rest of the year. Permeability is rapid. If drained, the organic material initially shrinks to about half the original thickness and then subsides further as a result of compaction and oxidation. These losses are most rapid during the first 2 years. If drained, the soil continues to subside at a rate of about 1 inch per year. The lower the water table, the more rapid the loss.

The natural vegetation consists of sawgrass, willow, and cattail. Under natural conditions, this soil generally is not suited to cultivation. If water is controlled through a system of dikes, ditches, and pumps, however, the soil is well suited to most winter vegetable crops. A well designed and maintained water-control system can remove excess water during periods when crops are growing on the soil and can keep the soil saturated at all other times. Keeping the soil saturated minimizes oxidation. Important management practices include good seedbed preparation and a suitable crop rotation. Cover crops and crop residue should be left on the surface or plowed under. Fertilizer should be applied according to the needs of the crop.

This soil is not suited to the production of citrus, avocados, or pine trees because of the wetness.

This soil is suited to pasture. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Maintaining the water table near the surface helps to prevent excessive subsidence of the organic material. Regular applications of fertilizer and controlled grazing are needed.

This soil is not used as rangeland. It is in the Freshwater Marsh ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the ponding, excess humus, low strength, and the depth to bedrock. Water-control measures are needed to prevent excessive wetness. The organic material should be removed, and suitable backfill material should be provided. Sealing or lining sewage lagoons and trench sanitary landfills with impervious soil material helps to prevent seepage. The sides of shallow excavations should be shored. Mounding may be needed on sites for septic tank absorption fields.

The capability subclass is IVw.

34—Hallandale fine sand.

This shallow, nearly level, poorly drained soil is on broad flats between the Everglades and the low, sandy coastal ridge. Individual areas are broad and irregularly shaped and range from 50 to 1,000 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Hallandale fine sand, Hallandale and similar soils make up 82 to 99 percent of the mapped areas.

Typically, the surface layer is very dark gray fine sand about 4 inches thick. Below this is 8 inches of light brownish gray fine sand that has common black and very dark gray streaks in old root channels. The subsoil is brown fine sand about 4 inches thick. Soft, porous limestone bedrock is at a depth of about 16 inches.

Included in mapping are small areas of Margate soils and soils that are similar to Hallandale fine sand but have limestone bedrock at a depth of less than 7 or more than 20 inches or have an organic surface layer that is less than 8 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of Plantation soils, small areas of Udorthents, and small areas where more than 20 inches of fill material has been added to the surface. Dissimilar soils make up 1 to 18 percent in most mapped areas. Plantation soils are in the lower positions on the landscape. They have an organic surface layer. Udorthents are in the higher filled areas that have coarse fragments.

During most years the water table in the Hallandale soil is within a depth of 12 inches for 4 to 6 months and is at a depth of 12 to more than 24 inches for the rest of the year. Permeability is rapid.

Most of the acreage is pasture or idle land. The natural vegetation consists of slash pine, melaleuca, and Australian pine. The understory includes pineland threeawn, chalky bluestem, paspalum, bluejoint panicum, and scattered saw palmetto.

This soil generally is not suited to cultivation. Under natural conditions, it is poorly suited to the production of citrus and pine trees and unsuited to the production of avocados because of the wetness. If a good water-control system is maintained and proper management is applied, however, the soil is well suited to most vegetable crops, citrus, ornamental plants, and improved pasture. Important management practices include bedding in areas used for citrus, ornamental plants, or root crops. The proper kinds and amounts of fertilizer, lime, and irrigation water should be applied according to the needs of the crop. Cover crops and crop residue should be left on the surface or plowed under. In areas of improved pasture, controlled grazing is needed to prevent overgrazing and the subsequent invasion of the less desirable forage species.

This soil is not used as rangeland or forest land. It is in the Everglades Flatwoods ecological plant community.

This soil is severely limited as a site for urban uses because of the wetness and the depth to bedrock. Local construction methods generally can overcome these limitations. The soil commonly is used for urban development.

The capability subclass is IVw.

35—Margate fine sand.

This moderately deep, nearly level, poorly drained soil is on low terraces between the Everglades and the sandy coastal ridge. Individual areas are broad and irregularly shaped and range from 10 to 500 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Margate fine sand, Margate and similar soils make up 98 to 99 percent of the mapped areas.

Typically, the surface layer is very dark gray fine sand about 9 inches thick. The subsurface layer, to a depth of about 18 inches, is light brownish gray fine sand. The next 10 inches is brown fine sand. Below this, to a depth of about 36 inches, is dark grayish brown fine sand. Soft, porous limestone bedrock is at a depth of about 36 inches.

Included in mapping are small areas of Hallandale and Plantation soils and soils that are similar to Margate fine sand but are more than 40 inches deep over limestone bedrock.

Dissimilar soils that are included with this soil in mapping occur as small areas of Udorthents and small areas where more than 20 inches of fill material has been added to the surface. Dissimilar soils make up 2 percent or less of most mapped areas. Udorthents are in the higher filled areas that have coarse fragments.

During most years the water table in the Margate soil is within a depth of 12 inches for 4 to 6 months and is at a depth of 12 to more than 24 inches for the rest of the year. Permeability is rapid.

Most areas are used as improved pasture. The natural vegetation consists of scattered slash pine and cabbage-palm, melaleuca, and Australian pine. The understory includes scattered saw palmetto, pineland threeawn, chalky bluestem, bluejoint panicum, and paspalum.

This soil generally is not suited to cultivation. Under natural conditions, it is poorly suited to the production of citrus and pine trees and unsuited to the production of avocados because of the wetness. If a good water-control system is maintained and proper management is applied, however, the soil is well suited to most vegetable crops, citrus, and improved pasture. The proper kinds and amounts of fertilizer, lime, and irrigation water should be applied according to the needs of the crop. Cover crops and crop residue should be left on the surface or plowed under. In areas of improved pasture, controlled grazing is needed to prevent overgrazing and the subsequent invasion of the less desirable forage species. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed.

This soil is not used as rangeland or forest land. It is in the Everglades Flatwoods ecological plant community.

This soil is severely limited as a site for urban uses because of the wetness, the depth to bedrock, and the hazard of seepage. Local construction methods generally can overcome these limitations. The soil commonly is used for urban development.

The capability subclass is IVw.

37—Basinger fine sand.

This deep, nearly level, poorly drained soil is in sloughs and poorly defined drainageways. Individual areas range from 80 to 147 acres in size. Slopes are less than 2 percent.

On 95 percent of the acreage mapped as Basinger fine sand, Basinger and similar soils make up 90 to 100 percent of the mapped areas.

Typically, the surface layer is very dark gray fine sand about 6 inches thick. The next 24 inches is light gray fine sand. The subsoil is brown and light brownish gray fine sand about 20 inches thick. Below this to a depth more than 80 inches is light brownish gray fine sand.

Included in mapping are soils that are similar to Basinger fine sand, but have limestone bedrock within a depth of 80 inches, have a subsurface layer that is more than 30 inches thick, or become lighter colored with increasing depth.

Dissimilar soils that are included with this soil in mapping occur as small areas of Dade, Plantation, and Pomello soils and small areas of Udorthents. Dissimilar soils make up less than 10 percent of most mapped areas. Dade soils are on low hills and are well drained. Plantation soils have an organic surface layer. They are in the lower positions on the landscape. Pomello soils have a well developed, sandy subsoil. They are in the higher positions on the landscape. Udorthents are in filled areas that have coarse fragments.

The water table in the Basinger soil is within a depth of 12 inches for 1 to 6 months in most years. Permeability is rapid.

Most of the acreage has been cleared and is used as improved pasture or is idle land. The natural vegetation consists of waxmyrtle, pineland threeawn, and scattered slash pine.

Under natural conditions this soil is poorly suited to row crops, citrus, avocados, and improved pasture because of the wetness. If a good water-control system is maintained and proper management is applied, however, the soil is well suited to most vegetable crops, citrus, and improved pasture. The proper kinds and amounts of fertilizer, lime, and irrigation water should be applied according to the needs of the crop. Cover crops and crop residue should be left on the surface or plowed under. In areas of improved pasture, controlled grazing is needed to prevent overgrazing and the subsequent invasion of the less desirable forage species. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed.

This soil is not used as rangeland or forest land. It is in the Slough ecological plant community.

This soil is severely limited as a site for most kinds of urban development, sanitary facilities, and recreational development because of the wetness, the hazard of seepage, and the sandy texture.

The capability subclass is IVw.

38—Rock outcrop-Vizcaya-Biscayne complex.

This map unit consists mainly of Rock outcrop intermingled with areas of Vizcaya and Biscayne soils. The Rock outcrop and Vizcaya and Biscayne soils occur as areas so intermixed or so small that mapping them separately is impractical. Individual areas range from 5 to several thousand acres in size. Slopes are less than 2 percent.

On 95 percent of the acreage mapped as Rock outcrop-Vizcaya-Biscayne complex, Rock outcrop and Vizcaya, Biscayne, and similar soils make up 91 to 100 percent of the mapped areas. About 56 percent of this map unit is Rock outcrop; 28 percent is Vizcaya soil, which is in the lower positions on the landscape; and 14 percent is Biscayne soil, which is on flats.

Typically, the Vizcaya soil is black mucky silt loam in the upper 6 inches. Below this, to a depth of about 15 inches, is black clay. Hard, porous limestone bedrock is at a depth of about 15 inches.

Typically, the Biscayne soil consists of about 4 inches of grayish brown marl that has texture of silt loam. Hard, porous limestone bedrock is at a depth of about 4 inches.

Included in mapping are soils that are similar to the Vizcaya soil but are less than 8 or more than 20 inches deep over limestone bedrock.

Dissimilar soils that are included with the Vizcaya and Biscayne soils in mapping occur as small areas of Lauderhill, Pahokee, and Terra Ceia soils. Dissimilar soils make up 9 percent or less of most mapped areas. They are organic. They are on the lowest part of the landscape.

Under natural conditions, the water table in the Vizcaya soil is at or above surface for 2 to 6 months and at a depth of more than 12 inches for the rest of the year. The water table in the Biscayne soil is at the surface for 2 to 4 months. Permeability slow in the Vizcaya soil and moderate in the Biscayne soil.

Most areas support natural vegetation. Water-tolerant vegetation, such as South Florida bluestem, sawgrass, gulf muhly, cabbage-palm, and willow, dominates the landscape. Dense stands of vegetation are in rock cavities and solution holes.

Under natural conditions, this map unit is not suitable for fruit or vegetable crops, ornamental plants, or pasture. If drained and rock-plowed, the map unit becomes Biscayne gravelly marl or Chekika very gravelly loam, depending on the depth to limestone and the amount and type of material incorporated from the solution holes during plowing.

This map unit is not used as rangeland or forest land. It is in the Freshwater Marsh ecological plant community.

This map unit is severely limited as a site for urban uses and recreational development because of the wetness and the depth to bedrock. Additional drainage measures and large amounts of suitable fill material are needed to overcome these limitations.

The Rock outcrop is not assigned a capability classification. The Vizcaya and Biscayne soils are in capability subclass VIIw.

39—Beaches.

This map unit consists of nearly level to sloping, narrow strips of tide- and surf-washed sandy material and shell fragments along the shoreline of the Atlantic Ocean. It commonly is a mixture of moderately alkaline sandy material and fine shell fragments.

The beaches are less than 100 to 300 feet wide. As much as half of the beach area may be flooded daily during high tides, and all of it can be flooded by storm tides. Most of the beaches have a uniform gentle slope that extends to the edge of the water, although the shape and gradient of the slope can change with every storm.

This map unit generally supports no vegetation, although some clumps of seaoats, railroad vine, and other salt-tolerant plants are near some of the inland edges.

Depth to the water table varies considerably, commonly ranging from 0 to 6 feet, depending on distance from the shore, elevation of the beach, and the tides.

This map unit can be used only as recreational areas and wildlife habitat. Severe erosion is often a problem during severe storms. Because they have great esthetic value, the beaches are an important part of the coastline.

No capability classification is assigned.

40—Pomello sand.

This deep, nearly level, moderately well drained soil is on moderately high, broad hills on the Miami Ridge. Individual areas are irregularly shaped and range from 10 to 100 acres in size. Slopes are smooth. They generally are less than 2 percent but range to 5 percent.

On 95 percent of the acreage mapped as Pomello sand, Pomello and similar soils make up 98 to 99 percent of the mapped areas.

Typically, the surface layer is dark gray sand about 5 inches thick. The subsurface layer, to a depth of about 35 inches, is sand. It is light gray in the upper 10 inches and gray in the lower 20 inches. The upper 41 inches of the subsoil is very dark grayish brown sand. The lower part to a depth of 80 inches or more is dark yellowish brown sand.

Included in mapping are soils that are similar to Pomello sand, but are well drained or somewhat poorly drained, have a weakly developed subsoil, have limestone bedrock below a depth of 70 inches, or have a surface layer that is as much as 10 inches thick.

Dissimilar soils that are included with this soil in mapping occur as small areas of the poorly drained Basinger soils on the lower part of the landscape. These soils make up 1 to 2 percent of the map unit.

Under natural conditions, the water table in the Pomello soil is at a depth of 24 to 42 inches for about 1 to 4 months in most years and is at a depth of 40 to 60 inches during the drier periods. Permeability is moderately rapid.

Most of the acreage has been cleared for development or is idle land. Some areas support natural vegetation, which consists of slash pine and scattered post oak. The understory vegetation in these areas includes pineland threeawn, opuntia, and various weeds and grasses.

Under natural conditions, this soil is poorly suited to cultivated crops because of droughtiness. Irrigation is needed. Important management practices include timely applications of the proper amounts of fertilizer and lime.

The suitability of this soil pasture is fair. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed. Regular applications of fertilizer are needed. Irrigation is needed during dry periods. Controlled grazing helps to prevent overgrazing and maintains plant vigor.

This soil is poorly suited to the production of citrus and mangos. Only fair yields can be obtained even if the level of management is high. A water-control system is necessary to maintain the water table at a depth of about 4 feet during wet periods and to provide water for irrigation during periods of low rainfall. Regular applications of fertilizer and lime are needed for maximum yields. A suitable cover crop between the tree rows can help to control soil blowing. The soil is unsuited to avocado production.

This soil generally is not used as rangeland or forest land. Under natural conditions, it is in the Sand Pine Scrub ecological plant community.

This soil is severely limited as a site for sanitary facilities and recreational development. It is moderately limited as a site for dwellings without basements and for small commercial buildings. Water-control measures are needed to prevent excessive wetness. Enlargement of septic tank absorption fields may be needed because of the wetness. Because of a poor filtering capacity, the effluent from these fields can pollute ground water. Community sewage systems help to prevent the contamination of ground water in areas of moderate or high housing density. The sandy surface layer should be stabilized in areas used for recreational purposes. Water-control measures are needed. The sides of shallow excavations should be shored.

The capability subclass is VIs.

41—Dade fine sand.

This moderately deep, nearly level, well drained soil is on broad, low hills on the Miami Ridge. Individual areas are irregularly shaped and range from 10 to 100 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as Dade fine sand, Dade and similar soils make up 99 to 100 percent of the mapped areas.

Typically, the surface layer dark gray fine sand about 6 inches thick. Below this is light brownish gray fine sand about 18 inches thick. The subsoil is dark grayish brown fine sand about 3 inches thick. Soft, porous limestone bedrock is at a depth of about 27 inches.

Included in mapping are soils that are similar to Dade fine sand but have limestone bedrock within a depth of 20 inches and do not have subsoil layer that is well coated with organic matter, have limestone bedrock at a depth of more than 80 inches, or are moderately well drained.

Dissimilar soils that are included with this soil in mapping occur as small areas of Pomello soils in the slightly lower positions on the landscape. These soils are not underlain by limestone bedrock. They make up about 1 percent of the map unit.

Under natural conditions, the water table in the Dade soil is at a depth of 60 to 72 inches for 1 to 3 months during most years and is below a depth of 72 inches for the rest of the year. Permeability is very rapid throughout the profile.

Most areas have been cleared for development. Some areas support natural vegetation, which consists of pineland threeawn, slash pine, live oak, scrub oak, and saw palmetto.

Under natural conditions, this soil is not suited to cultivation or the production of citrus, avocados, or pine trees. It is poorly suited pasture because of droughtiness. If irrigated and properly managed, the soil is well suited to most cultivated crops, citrus, ornamental plants, and improved pasture. Important management practices include applying the proper kinds and amounts of fertilizer and irrigation water according to the needs of the crop. Cover crops and crop residue should be left on the surface or plowed under. In areas of improved pasture, controlled grazing is needed to prevent overgrazing and the subsequent invasion of the less desirable forage species. Common bermudagrass and improved bahiagrass grow well if the pasture is properly managed.

This soil is not used as rangeland or forest land. It is in the Everglades Flatwoods ecological plant community.

Most of the acreage of this soil is in areas that are being developed for urban uses. The soil is moderately limited as a site for local roads and streets, small commercial buildings, and dwellings without basements. It is severely limited as a site for dwellings with basements because of the depth to bedrock and as a site for septic tank absorption fields and sanitary landfills because of the to bedrock and a poor filtering capacity or seepage.

The capability subclass is VIs.

42—Udorthents, limestone substratum, 0 to 5 percent slopes.

These nearly level or gently sloping, moderately well drained or well drained soils consist of thin or thick deposits of fill material. The fill material has been excavated from nearby areas and spread over the surface. It commonly is about 30 inches thick. Individual areas range from 40 to 800 acres in size.

No one pedon represents these soils, but in one of the most common profiles, the surface layer is dark gray gravelly sand about 4 inches thick. Below this, to a depth of about 30 inches, are light gray, unconsolidated limestone fragments. Hard, porous limestone bedrock is at a depth of about 30 inches.

Included with these soils in mapping are small areas of soils that have slopes of more than 5 percent. Also included are small areas of Urban land, which makes up 15 percent or less of the map unit.

Depth to the water table in the Udorthents varies, depending on the amount of fill material and the drainage measures in a given area. In most areas the water table is below a depth of 40 inches. Permeability generally is rapid.

Most areas are used as sites for golf courses. The existing vegetation consists of grasses and ornamental trees and shrubs.

No capability classification is assigned.

45—Canaveral sand.

This very deep, nearly level or gently sloping, moderately well drained soil is on low, dunelike ridges. Individual areas are long and narrow and range from 10 to 200 acres in size. Slopes are dominantly less than 3 percent but range to 5 percent.

On 95 percent of the acreage mapped as Canaveral sand, Canaveral and similar soils make up 99 to 100 percent of the mapped areas.

Typically, the surface layer is dark grayish brown sand about 4 inches thick. About 10 percent of this layer is sand-sized shell fragments. The next 46 inches is pale brown sand in which the content of sand-sized shell fragments is about 20 percent. The lower 30 inches is gray sand in which the content of sand-sized shell fragments is about 25 percent.

Included in mapping are soils that are similar to Canaveral sand, but are better drained.

Dissimilar soils that are included with this soil in mapping occur as small areas of poorly drained soils that have a black surface layer. These soils make up about 1 percent of the map unit.

During most years the water table in the Canaveral soil is at a depth of 24 to 36 inches for 2 to 4 months and is at a depth of 36 to 60 inches for the rest of the year. It is at a depth of 12 to 24 inches after periods of heavy rainfall. Permeability is very rapid.

The natural vegetation consists of sand live oak, cabbage-palm, and scattered saw palmetto. Exotic tree species, including Australian pine and Brazilian pepper, have become established in some areas.

This soil is not suited to cultivated crops or improved pasture. A low available water capacity and low natural fertility severely reduce the variety of grasses that can be grown on the soil.

This soil is poorly suited to the production of citrus, mangos, and avocados. The suitability for these crops is fair, however, if intensive management measures, including irrigation and regular applications of fertilizer, are applied. A close-growing crop between the trees helps to control soil blowing.

This soil is not used as rangeland or forest land. It is in the South Florida Coastal Strand ecological plant community.

This soil is severely limited as a site for buildings, sanitary facilities, and recreational development because of the wetness. Extensive water-control measures and large amounts of suitable fill material are needed to overcome this limitation. The sandy surface layer should be stabilized in areas used for recreational purposes. Water-control measures are needed. Sealing or lining trench sanitary landfills and sewage lagoons with impervious soil material helps to prevent seepage. The sides of shallow excavations should be shored. Because of the droughtiness of the soil, native plants should be selected for landscaping.

The capability subclass is VIs.

47—St. Augustine sand.

This deep, nearly level, somewhat poorly drained soil is on Key Biscayne. Individual areas range from 20 to 400 acres in size. Slopes are smooth and are less than 2 percent.

On 95 percent of the acreage mapped as St. Augustine sand, St. Augustine and similar soils make 85 to 99 percent of the mapped areas.

Typically, the surface layer is dark brown sand about 3 inches thick. Below this is 48 inches of gray and light gray sand that has common fine lenses of gray marl in the lower 22 inches. The subsoil is gray and light gray sand about 29 inches thick. It has few fine lenses of gray marl in the upper 6 inches.

Included in mapping are soils that are similar to St. Augustine sand, but do not have pockets of loamy material or marl, have a thin or weakly pronounced organic layer at a depth of more than 60 inches, have pockets of organic material or shell fragments, or are poorly drained.

Dissimilar soils that are included with this soil in mapping occur as small areas of poorly drained soils that have a dark surface layer. These soils are in the lower positions on the landscape. They make up less than 10 percent of most mapped areas.

In most years the water table in the St. Augustine soil is at a depth of 18 to 36 inches for 2 to 6 months. In some areas daily tides influence the water table, depending on the amount of fill material. Permeability is moderately rapid.

Most of the acreage supports Australian pine and weedy grasses. Some areas have been developed for urban uses.

This soil is not used for cropland, improved pasture, citrus, ornamental plants, or pine trees. It consists of mixed soil material used as fill in low tidal areas. The fill improves the suitability of the low areas for building site development and other urban uses. The suitability of this soil for urban uses is only fair because of brief periods of wetness. The soil is severely limited as a site for most recreational uses because of the sandy texture. Onsite investigation is needed to determine the suitability for any use.

The capability subclass is VIIs.

48—Kesson muck, tidal.

This deep, nearly level, very poorly drained soil is in tidal mangrove swamps along the coast in southeastern Florida and is subject to tidal flooding. Individual areas range from 10 to 200 acres in size. Slopes are less than 1 percent.

On 95 percent of the acreage mapped as Kesson muck, tidal, Kesson and similar soils make up 90 to 99 percent of the mapped areas.

Typically, the surface layer is black muck about 6 inches thick. The next 6 inches is dark gray fine sand mixed with shell fragments. The substratum to a depth of 80 inches is grayish brown and light gray fine sand mixed with shell fragments.

Included in mapping are soils that are similar to Kesson muck but have an organic surface layer that is more than 8 inches thick or have a thin surface layer of marl.

Dissimilar soils that are included with this soil in mapping occur as small areas of the tidal Pennsuco soils and small areas of Udorthents. Dissimilar soils make up less than 10 percent of most mapped areas. Pennsuco soils are in positions on the landscape similar to those of the Kesson soil. They are made up of marl and are underlain by limestone bedrock. Udorthents are in the slightly higher filled areas that have coarse fragments.

Under natural conditions, the Kesson soil remains saturated. Fluctuating tides cover the surface twice daily. Permeability is moderately rapid.

The native vegetation consists mainly of red and black mangrove. White mangrove grows in some areas.

Because of tidal flooding, this soil is not suited to cropland, citrus, or improved pasture.

This soil is not used as rangeland. It is in the Mangrove Swamp ecological plant community.

This soil is not suited to urban uses because of tidal flooding.

This soil is in mangrove swamps, which are unique and biologically productive areas that are important to many species of fish and wildlife. Many sport and commercial finfish, shellfish and other crustaceans use these areas as spawning grounds. Mangrove swamps in estuaries also serve as protective barriers against excessive wave action during tropical storms.

The capability subclass is VIIIw.

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