Copper soil, deficient

A small amount of copper is consumed for copper salts such as copper sulfate, which are important as agricultural fungicides as a spray or a dust. Copper salts are occasionally used to correct local soil deficiencies. Copper sulfate itself is also an excellent algicide in swimming pools and fish rearing ponds. 

Fertile soils supply plants with all of the trace elements essential for growth, believed at the present time to be Fe, Mn, Zn, B, Cu, Mo, and CL These seven elements are called the micronutrients, a term that indicates the small quantities needed by plants but not necessarily the concentrations found in soils. Deficiencies can occur in soils either because they contain extremely low concentrations of these elements or because the elements are present in very unavailable (insoluble) forms. Conversely, many trace elements, including ail of the micronutrients, can reach concentrations in soils that are toxic to plants and microoiganisms. Some of the most toxic are mercury (Hg), lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), and cobalt (Co). The first three are particularly toxic to higher animals. The last three are more toxic to plants than animals and are termed phytotoxic. From the standpoint of potential hazard to human health, an extended Ust of priority metals has been established. This list presently consists of ... 

Acid conditions, like the presence of acid rain in the region, promote the solubility of copper ores or metal. Alkaline conditions tend to precipitate copper and may lead to deficiency of the metal in plants. Similarly, if the soil is excessively acid, the solubilized copper salts may leach out and also lead to metal deficiency. Evidently, soil deficiency of copper can lead to plant deficiency which may prove lethal to susceptible animals. 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

In addition to all of the expected enzyme systems present in leaf tissue, fresh tea leaves contain a high level of polyphenol oxidase that catalyzes the oxidation of the catechins by atmospheric oxygen. Tea polyphenol oxidase exists as series of copper-containing (0.32%) isoenzymes. The major component has a molecular weight of about 144,000.54 The enzyme is concentrated in the leaf epidermis.55 Soil copper deficiency is sometimes responsible for inadequate oxidation during processing.56... 

Copper sulfate can be described as a by-product of copper refining that is obtained by crystallization of the weak liquor. The copper sulfate precipitate formed is centrifuged, dried, screened, and finally packaged in bags and drum. However, it is produced in some chemical industries by reacting copper shot with sulfuric acid, air, and water. It is widely used as an insecticide, additive nutrients (for soils that are deficient in copper), copper electroplating, wood preservation, and in petroleum refining. 

Loessial soils in the Loess Plateau contained 0.01-4.20 mg/kg DTPA-extractable Cu with an average of 0.93 mg/kg (Table 7.7). Bioavailable Cu in the North China Plain varied from 0.07-9.95 mg/kg. In the North West region, soils contained 0.06-19.20 mg/kg DTPA-extractable Cu. The average bioavailable Cu was 1.83 mg/kg in the calcareous paddy soils with a range of trace to 6.85 mg/kg. Copper deficiency was not often observed in the arid and semi-arid soils of China. 

Karamanos, R.E., Kruger, G.A. and Stewart, J.W.B. (1986). Copper deficiency in cereal and oilseed crops in Northern Canadian prairie soils , Agronomy Journal, 78, 317-323. 

No evidence of copper deficiency exists in terrestrial species of invertebrates examined. However, relatively low concentrations of copper stimulated growth and reproduction. Reproduction in mites (Platynothrus peltifer) increases when fed diets containing 28 mg Cu/kg DW (vs. 13 mg/kg in controls) for 3 months (Denneman and van Straalen 1991). Also, juveniles of earthworms (Eisenia andrei) show increased growth at 18 mg Cu/kg DW soil after 12 weeks (van Gestel et al. 1991). 

Zinc in Plant and Animal Nutrition. In 1854 A. Braun discovered the presence of zinc in plants and m 1869 J. Raulin proved diat it is essential for the growth of Aspergillus (153, 154). Its important role in die nutrition of many plants and animals has been demonstrated repeatedly (104, 105). When some pecan tines growing on a copper-deficient soil were treated widi a copper solution, die only trees which responded favorably were those treated with a solution which had been stirred up in a galvanized bucket and therefore contained zinc unintentionally (106). Zinc solutions are now used in the treatment of pecan rosette and other zinc-deficiency diseases of fruit trees and nut-bearing trees in the western states (112). 

Cationic antagonisms induced by trace elements excesses have been demonstrated in plants as well as animals. Excesses of either manganese or iron in soil have resulted in deficiencies of the other in soybeans (152). Likewise, excess soil concentration of copper has resulted in manganese deficiency in crops (153). Plants, like animals, also demonstrate chromosomal aberrations (particularly to aluminum and cadmium) (15) as well as enzymatic alterations in response to excess exposure (16). 

The effects nf copper deficiency in plants are varied and include die-back. inability to produce seed, chlorosis, and reduced photosynlhetic activity. In contrast, excesses of copper in the soil are toxic, as in the application of soluble copper salts to foliage. Fur this reason, copper fungicides are formulated with a relatively insoluble copper compound. Their toxicity to fungi ttrises from Lhe fact tltal (he latter produce compounds, primarily hydroxy and amino acids, which can dissolve the copper compounds from lhe fungicide. 

Copper deficiency in plants is most frequent on organic soils, such as newly drained bogs, and on very sandy soils The severe copper deficiency often found when bogs and marshes are first used for crop production is called nyUinutliori disease in some parts of the world. 

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