Soil, characteristics color

What common soil characteristics are indicated by soil color Explain how a soil s color is described. 

The resultant magenta color is remarkably intense per unit of parathion this, and other characteristics, indicated the ready adaptability of this method to the quantitative estimation of parathion in and on fruits, vegetables, foliage, and woody tissues, and in soil. The present paper reports upon endeavors to define or elaborate upon the parameters... 

As a soil develops, OM decomposes to produce humus, which is black. Additionally, release of iron from minerals by weathering yields various reds and yellows. Both mechanisms yield soil coloring agents. Under oxidizing conditions, where soil is not saturated with water, the iron will be oxidized and thus in the ferric state [Fe(III)]. When the iron and OM are deposited on the surfaces of sand, silt, clay, and peds, they develop a coat that gives them a surface color. However, soil color is not only a surface characteristic but extends through the soil matrix. Under oxidizing conditions, soil has a reddish color. The chroma of this color depends to some extent on the amount of and the particular iron oxide present. 

Under saturated or very wet conditions, soils tend to have increased amounts of OM. This results in dark colors and dramatically changes the chemical characteristics of a soil. OM increases a soil s sorptive and cation exchange capacities and thus alters the movement and extraction of components present. OM increases ped formation and stability, thus increasing both aeration and percolation, but under saturated conditions, reduction reactions prevail (see Figure 2.12). 

Soils develop by the action of the soil forming factors on soil parent materials including material transported by different agents. The result of these soil forming factors is the formation of soil horizons, different colors, and peds. Each of these factors has a pronounced effect on a soil s chemistry. Knowledge of the soil type and profile description can provide the soil chemist, analyst, or researcher with valuable information about the characteristics of soil relevant to the development of extraction, analytical, and instrumental analytical procedures. It also is the place to start when investigating the failure of a procedure. 

The topography of an area must also be taken into account when gridding it for nonpoint sampling [4,5], The tops of slopes will have more erosion of contaminates and soil. Thus, they will generally be lower in contaminant concentration. Lower areas, particularly where water ponds or accumulates, will have higher concentrations of contaminants. Soil color is a valuable characteristic to observe and record in these situations. The tops of slopes will be lighter and typically redder in color, while lower areas will have darker soil colors. 

Dissolved humic substances (DHS) are the main constituents of the dissolved organic carbon (DOC) pool in surface waters (freshwaters and marine waters), groundwaters, and soil porewaters and commonly impart a yellowish-brown color to the water system. Despite the different origins responsible for the main structural characteristics of DHS, they all constitute refractory products of chemical and biological degradation and condensation reactions from plant or animal residues and play a crucial role in many biogeochemical processes. 

Humic substances A series of relatively high-molecular-weight, yellow- to black-colored substances formed by secondary synthesis reactions. The term is used as a generic name to describe the colored material or its fractions obtained on the basis of solubility characteristics. These materials are distinctive to the soil (or sediment) environment in that they are dissimilar to the biopolymers of microorganisms and higher plants (including lignin)... 

Arai,Y. Sparks, D.L. (2001) ATR-ETIR spectroscopic investigation on phosphate adsorption mechanisms at the ferrihydrite-water interface. J. Coll. Int. Sd. 241 317—326 Araki, S. Hirai, H. Kyuma, K. (1986) Phosphate absorption of red and/or yellow colored soil materials in relation to the characteristics of free oxides. Soil Sd. Plant Nutr. 32 609-616... 

The domestic cow, however, is by far the most abundant cow in agriculture. This species can be used as a draft animal, in which case they are referred to as oxen. These animals are very strong and are capable of hauling heavy loads or plowing soil. There are various races of domestic cows, which vary in the length and shape of their horns, body size and shape, body color, and other characteristics. The black-and-white blotched holstein is a familiar variety, as is the uniformly light-brown jersey. 

Field descriptions of soil profiles include horizon designations and thicknesses, color, consistency, texture, structure, and boundary characteristics. The nomenclature used is that of the 7th Approximation (7). The... 

Because Fe is mobilized by reduction, it can be redistributed over a range of distances within a soil horizon, a soil profile or even a soil-scape. This characteristic together with the fact that there are several different Fe oxides, results in numerous occurrences of these compounds in weathering environments. This can be illustrated with color slides, if time is available. 

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