The topography of the rock foundation on which the cumulative deposits have been built is, in reality, not similar to a basin but more comparable to a broad and open trough fifty miles wide and a hundred miles long. The Everglades are a component of an immense hydrologic unit consisting of the Kissimmee River Valley as the watershed, Lake Okeechobee as the storage basin, and the Everglades as the overflow area. Seen in this light,

The northern and eastern sections of the Everglades are nearly devoid of trees, being covered with saw grass (Mariscus jamicensis), a sedge growing in dense tussocks to heights of ten and twelve feet. Although saw grass covers most of the glades, bushes and trees of myrtle, willow, and bay often appear in sporadic clumps or little islands. On the eastern and western edges many islands or hammocks appear in close proximity to the mainland. These hammocks consist of a dense growth of broad leaved trees and shrubs and appear as true islands during periods of high water.³²

This rank growth of herbaceous vegetation has occupied this large trough through the center of southern Florida, and from its decay and settlement has built up the ground level at the southern shore of Lake Okeechobee to fourteen feet above bed rock. This thickness of the cumulative soils at Okeechobee gradually thins out to a feather edge at the sides of the Everglades.³³ Charles T. Simpson, a naturalist who spent a good many years in southern Florida, believed that "The southern part of the glades was recently elevated and there has not been sufficient time as yet . . . to form any great depth of vegetable deposits. In fact the rock appears on the surface over extensive areas in the newer part. . . ."³⁴

The publicity attending the progress of canal excavation and land sales in 1912 gave rise to a demand for information as to the chemical composition and productiveness of the soils of the Everglades. The examination of thirty-five samples of soils taken from Lake Okeechobee to Miami was the first scientific analysis of these soils. Previous to that time examinations of Florida muck soils had been on the basis of other localities in the state, principally in the Kissimmee-St. Cloud area. The analyses of the glades soil showed an exceedingly high nitrogen content with comparatively small quantities of potash and phosphates.³⁵ In 1913 State Chemist Rufus E. Rose reported that the soil would grow large crops of foliage plants without fertilization, but would need the addition of potash and phosphate for a satisfactory yield of grain or sugar.

A survey of the Everglades soils from the site of the rock rim at the head of the north branch of the New River at Ft. Lauderdale to the south shore of Lake Okeechobee was made in the winter of 1915, under the auspices of the United States Department of Agriculture. This soil survey covered a strip two and a half miles wide on each side of the North New River Canal. The surveyors reported that "From the rock rim to the shores of Lake Okeechobee the soils mapped in this survey are composed largely of organic matter in various stages of disintegration and decay."³⁶ Grouping the soils according to the percentage of mineral constituents and the stage of decomposition of the vegetable tissue, the survey located three classes of Everglades soils.

Near Lake Okeechobee, bordering the shore for a width of one to two miles, the material was found to be black and well decomposed, and averaged sixty percent ash content. The inorganic matter consisted of fine sand, silt, and clay, and gave the soil a heavy silty texture. Because of the growth of the custard apple tree on this type of soil, it has been called the custard apple muck.³⁷ "The best land in the Everglades is where the custard apple grows. Some claim the custard apple is there because the soil is naturally better, others that the soil is better because of the custard apple."³⁸ Silting, bird rookeries, depth, and age have all had a part in the development of this band at Okeechobee's edge. Baldwin and his associates measured the depth of the muck and noted that it averaged from forty to seventy-five inches, and that it was underlain with peaty-muck to the limestone at one hundred twelve to one hundred and fifty inches. The surface was flat with a very gentle slope away from an elevation of twenty-one feet above sea level at the water's edge.³⁹

Twenty-five years later, in 1940, the Soil Conservation Service of the federal government began mapping the Everglades soils, and found the most valuable to be the Okeechobee muck, known locally as custard apple. Bordering the shore of the big lake on the eastern and southern exposures for a distance of one to three miles, this earth measured from thirty to sixty inches and lay on brown fibrous peat which in turn rested, on rock at a depth of five or more feet. A heavy, black, organic material with a high mineral content of from thirty to sixty per cent, this belt is highly desirable for the growth of sugar cane and vegetable crops.⁴⁰

South of the area of the custard apple muck, Baldwin and his associates surveyed a gradational belt of less decomposed material with a smaller percentage of mineral matter which they called Peaty Muck. Known throughout the Everglades as "Willow and Elder Land," because of this characteristic growth on a belt of two to four miles to the south and east of the Okeechobee muck, it consisted of a transition strip between the lake border soils and the Everglades Peat at its rear. With from six to eighteen inches of finely fibrous and partially rotted matter lying on a stratum of Okeechobee muck varying in thickness from two to thirty or more inches, it is underlain with peat to a depth of from five to eight feet before reaching the bed rock. Mapped by the 1940 survey as Okeelanta Peaty Muck, this soil has been found to be very desirable from the standpoints of both location and quality.⁴²

Approaching the interior of the Everglades away from Lake Okeechobee the material becomes less decomposed and is nearly pure organic matter. The 1915 survey came upon the soil which occupies the majority of the Everglades within two or three miles of the lake and mapped it as brown fibrous peat. The surveyors determined that this material averaged from eighty-five to ninety-three per cent combustible, and to comprise over sixty per cent of their mappings

In 1915 the depth of this region of Everglades Peat varied from 110 to 130 inches 10 miles south of the lake to 50 inches at the 32 milepost below the lake.

The 1940 Soil Survey identified the Everglades Peat as the most extensive soil type in the area. It found the top six to eighteen inches to be a fine, black, fibrous material containing up to fifteen per cent mineral matter, lying over rock or sand.⁴⁵

The agriculturally important types of organic soils surveyed in the Everglades to 1943 were: Okeechobee muck, deep and very deep phases: 25,000 acres; Okeelanta peaty muck, deep and very deep phases: 30,000 acres; Everglades peat, deep and very deep phases: 350,000 acres; and Everglades peat over sand: 130,000 acres.⁴⁶

In the portion north of the Hillsboro Canal and west of the Lake Worth Drainage District dikes, roughly the far northeastern corner of the Everglades, the 1940 Soil Survey mapped 165,000 acres of Loxahatchee peat. Found in the more inaccessible portions of the glades, this soil is a soft, felty, brown, fibrous material which is spongy in character, and in general has been laid down from tenderer plants than the saw grass. This earth loses three-fourths of its volume on drying and is not considered particularly desirable for agricultural purposes. Since it is covered with water during the greater part of the year it has been a refuge for frogs, fish, alligators, and ducks. Attempts to bring the Loxahatchee peat into cultivation have been generally unsuccessful.⁴⁷

Local classification of the soils of the Everglades has been according to the native vegetation growing upon them. The custard apple is a true muck of a sedimentary nature, while the saw grass is a true peat of an accumulative nature. The elderberry and willow is not distinct, but a combination of the other two.⁴⁸

Between 1940 and 1943, 5,800 of the 7,000 square miles in the Everglades and Everglades Drainage District had been surveyed and mapped by the United States Soil Conservation Service. The information obtained indicated that some 435,000 acres of the land examined was "suitable for long term use for crop production."⁴⁹ Non-agricultural organic soils, marls, sands, rock land, tidal marsh, and dredged land made up the remainder of the soils found in the Everglades and the district. The non-agricultural organic soils included Everglades peat of the shallow and very shallow phases and peat over shallow marl, as well as every phase of Loxahatchee peat. While a small percentage of the marls and sands have been brought into agricultural production, their most extensive use has been for dry weather grazing and wildlife and water conservation.⁵⁰

Chapter Notes

31 Garald G. Parker, "Notes on the Geology and Ground Water of the Everglades in Southern Florida," loc. cit., 52.

32 John K. Small, From Eden to Sahara: Florida's Tragedy, 14; M. H. Gallatin and J. R. Henderson, "Progress Report on the Soil Survey of the Everglades," The Soil Science Society of Florida, Proceedings, V-A (1943), 95-104.

33 Samuel Sanford, "The Topography and Geology of Southern Florida," loc. cit., 190-191; Charles Torrey Simpson, In Lower Florida Wilds, 119.

34 C. T. Simpson, In Lower Florida Wilds, 119-120.

35 R. E. Rose, "Analyses of Everglades Soils," Florida Department of Agriculture, Florida Quarterly Bulletin, XXXIII (January, 1913), 11.

36 Mark Baldwin, H. W. Hawker, and Carl F. Miller, Soil Survey of the Fort Lauderdale Area, Florida, 16. Hereinafter cited as Baldwin, Hawker, and Miller, Soil Survey.

37 Ibid., 17, 31.

38 John C. Gifford, The Tropical Subsistence Homestead, 89.

39 Baldwin, Hawker, and Miller, Soil Survey, 32.

40 Charles B. Evans and R. V. Allison, "The Soils of the Everglades in Relation to Reclamation and Conservation Operations," The Soil Science Society of Florida, Proceedings, IV-A (1942), 43.

41 Ibid.

42 "As usually mapped this soil has three distinct layers: (1) the surface 6 to 12 inches of finely fibrous, decomposed peat, (2) a layer of plastic, sedimentary muck which varies in thickness from 2 to 30 or more inches, and (3) another layer of fibrous, brown peat." M. H. Gallatin and J. R. Henderson, "Progress on the Soil Survey of the Everglades," loc. cit., 99.

43 Baldwin, Hawker, and Miller, Soil Survey, 35.

44 Ibid., 39.

45 Charles B. Evans and R. V. Allison, "The Soils of the Everglades in Relation to Reclamation and Conservation Operations," loc. cit., 44.

46 Separation into phases on the basis of depth was made as follows: more than 96 inches, very deep phase; 60 to 96 inches, deep phase; 36 to 60 inches, shallow phase; less than 36 inches, very shallow phase. M. H. Gallatin and J. R. Henderson, "Progress Report on the Soil Survey of the Everglades," loc. cit., 97-100.

47 Charles B. Evans and R. V. Allison, "The Soils of the Everglades in Relation to Reclamation and Conservation Operations," loc. cit., 45.

48 Harold E. Hammar, "The Chemical Composition of Florida Everglades Peat Soils, with Special Reference to their Inorganic Constituents," Soil Science, (July, 1929), 1-13.

49 M. H. Gallatin and J. R. Henderson, "Progress Report on the Soil Survey of the Everglades," loc. cit., 104.

50 Ibid., 100-104.