The orchrosols are highly coloured soils with little leaching characteristics (Dickson and Benneh 1980).
One stab with a spade was enough to open up the relics of this catastrophe--green-coloured soil and an acrid smell were silent witnesses to the inferno.
In the chestnut-coloured soil, the organic carbon and total nitrogen concentrations were 19.60 ± 0.18 g kg-1 and 4.18 ± 0.11 g kg-1, respectively.
Sandy and brown-coloured soils are common, and they are generally well-leached and have little humus content.
Vertisols are dark-coloured soils (though they have only moderate humus content) that may also be characterized by salinity and well-defined layers of calcium carbonate or gypsum.
Andosols are highly porous, dark-coloured soils developed from parent material of volcanic origin, such as volcanic ash, tuff, and pumice.
The so-called Shandong brown soils are found over most of the two major hill masses and include a variety of brown forest and cinnamon-coloured soils formed through clay accumulations and sod processes.
They are usually quite fertile, depending on both the length of time they have been cultivated and their proximity to urban centres, where heavier fertilization with human and animal wastes results in rich, dark-coloured soils.
These hills and the accompanying lava fields have dark soils spotted with lighter-coloured bunchgrass, which creates a leopard-skin effect that intensifies the desolate, windswept appearance of the Patagonian landscape.
Southern Bulgaria has forest soils with acidic (cinnamonic) traces by far the most extensive single category as well as the modified chernozems known as chernozem-smolnitzas (a dark-coloured zonal soil with a deep and rich humus horizon).
This solid, dark-coloured component of soil plays a significant role in the control of soil acidity, in the cycling of nutrients, and in the detoxification of hazardous compounds.
