158 SOILS AND AGRICULTURAL CONDITIONS 



and wind-blown sand, and containing less organic matter. This soil is quite 

 shallow, generally only a few inches deep, except where there has been special 

 opportunity for accumulation. 



The Bahama Black Loam is the principal type on all the islands, occupy- 

 ing approximately three-fourths of their area, while some of the smaller islands 

 are almost entirely covered by it. It covers the hills of the interior and the 

 slopes leading to the coast, wliere it passes into the Coral Sand. Where the 

 coast is abrupt it extends to the edge of the cliffs. It occupies, therefore, the 

 rougher portions of the surface. The rock outcrop is prominent; in fact, the 

 exposed rock forms the greater part of the surface, the soil filling the depres- 

 sions in the weathered rock and between the exposed boulders. Its elevated 

 position gives it perfect drainage, the water either flowing from the 

 surface, or, as is most common, filtering easily through the shallow soil into 

 the underlying porous rock. The loss of moisture by evaporation is also 

 great, so that the soil is subject to drought, rarely keeping in a moist condition 

 long at a time, where crops requiring clean cultivation are grown. The use 

 of cover crops, or mulches, particularly at dry periods, would do mucli to con- 

 serve the soil moisture. However, considering its shallowness, the soil retains 

 moisture fairly well, owing to its large content of organic matter. 



This soil occurs where the rock has weathered, leaving the surface in the 

 condition known as " plate rock," that is, where the surface of the underlying 

 rock is fiat, or nearly so. Where this plate rock occupies a low position, the 

 land is known as " plate-rock scrub," but the soil differs little from that on 

 higher elevations. Brackish ponds are numerous in the lower areas, and 

 probably the soil is not quite so good for crops because of the nearness of the 

 underlying salt water. 



This soil is mostly of residual origin, being derived from the weathering 

 of the underlying coralline rock. The process has been largely one of solution, 

 the residue being small in amount and consequently the resulting soil forma- 

 tion slow. The wind has also assisted in forming this soil, by carrying the 

 sand from the beaches inland, where it has fallen into the depressions and 

 pockets in the rock. Vegetation has sprung up, and by its decay a loamy soil 

 lias gradually formed, until finally a heavier plant growth could be supported. 

 The depth of the soil is dependent upon the depth of the pocket or depression 

 where it occurs. Usually these depressions are shallow and basin-shaped, 

 rarely exceeding one foot in depth. In the larger solution holes, known as 

 *' banana holes," the Bahama Black Loam has been washed in until it has a 



