Micronutrients, requirements for

Manahan, S.E. and Smith, M.J. Coppper micronutrient requirement for algae. Environ. Sci. Tech. 7, 829-833 (1973). 

Acid soils generally provide sufficient micronutrients, occasionally even toxic amounts, to plants or to animals grazing on those plants. Because of the small quantities of micronutrients required for plant growth, adequate amounts can be taken up from small portions of the root zone, if such regions are sufficiently acidic. In basic soils the acidity from fertilizers or from small quantities of elemental sulfur or sulfuric acid added to a portion of the root zone may provide adequate micronutrients to plants. 

The fermentation medium contains carbon, nitrogen and other macro- and micronutrients required for the growth of organism. Secretion of bacterial cellulose is usually most noticeable when the bacteria are supplied with an abundant carbon source and minimal nitrogen source [13]. Some authors uses a complex medium supplying amino acids and vitamins is also used to enhance the cell growth and production. 

The secondary nutrients for plants are calcium, magnesium, and sulfur. The micronutrients required for plants include boron, chlorine, copper, iron, manganese, molybdenum, sodium, vanadium, and zinc however, these nutrients are only needed in small quantities and rarely need to be replenished in soils. 

There are numerous variations of the wet process, but all involve an initial step in which the ore is solubilized in sulfuric acid, or, in a few special instances, in some other acid. Because of this requirement for sulfuric acid, it is obvious that sulfur is a raw material of considerable importance to the fertilizer industry. The acid—rock reaction results in formation of phosphoric acid and the precipitation of calcium sulfate. The second principal step in the wet processes is filtration to separate the phosphoric acid from the precipitated calcium sulfate. Wet-process phosphoric acid (WPA) is much less pure than electric furnace acid, but for most fertilizer production the impurities, such as iron, aluminum, and magnesium, are not objectionable and actually contribute to improved physical condition of the finished fertilizer (35). Impurities also furnish some micronutrient fertilizer elements. 

Copper is an essential micronutrient required in the growth of both plants and animals. In humans, it helps in the production of blood haemoglobin. In plants, copper is an important component of proteins found in the enzymes that regulate the rate of many biochemical reactions in plants. Plants would not grow without the presence of these specific enzymes. Research projects show that copper promotes seed production and formation, plays an essential role in chlorophyll formation and is essential for proper enzyme activity, disease resistance and regulation of water in plants (Rehm and Schmitt, 2002). 

Requirements for micronutrients (i.e., electrolytes, trace elements, and vitamins) vary with age, gender, route of administration, and underlying clinical conditions. 

Vitamin A is a necessary micronutrient in the diet for vision, growth, tissue differentiation, reproduction, and maintenance of the immune system. A deficiency of vitamin A affects reproduction in both male and female experimental animals. In the male, retinol is required for normal spermatogenesis in the female, the vitamin is necessary for both conception and normal development of the fetus. 

As rocks are transformed to soil so a proportion of each element is usually converted to a form which plant roots can absorb. Consequently, most of the elements in the Periodic Table would probably be detected in any plant sample if sufficiently sensitive analytical methods were used. Uptake of an element is no evidence that it plays any role in the development of the plant since a root has no power to reject any soluble element entirely. One must therefore differentiate between those elements which are needed, the essential nutrients, and the rest. The conventional criteria by which the presence of an element is regarded as essential rather than adventitious are these the plant cannot complete its life cycle in the absence of the element the action of the element must be specific in that no other element can wholly substitute for it nor is the element simply involved in beneficially altering the plants root environment the element must be shown to be a constituent of an essential metabolite, or required for the proper functioning of an essential enzyme system or be uniquely involved in maintaining the overall ionic composition of tissue. Table 1-2 lists the elements which are generally accepted as being essential for plants. Major or macronutrients are separated from micronutrients, the latter being present in tissue concentration < 0.1 %. 

Use and exposure Zinc is available as a silver or bluish-white foil or powder. It is incompatible with amines, cadmium, sulfur, chlorinated solvents, strong acids, and strong bases. The important use of zinc is to coat iron or steel in a process called galvanization to prevent rust. Zinc powder is very flammable. Zinc is another essential micronutrient that is important in immunity and antioxidation. Zinc is an essential mineral that is found in almost every cell function. It stimulates the activity of approximately 100 enzymes, which are substances that promote biochemical reactions in the body. Zinc supports a healthy immune system that the body requires for wound healing. It helps to maintain a sense of taste and smell and is needed for DNA synthesis. Zinc supports normal growth and development during pregnancy, childhood, and adolescence. ... 

Soil, water, and foliar analyses in coconut plantations are conducted to determine the type of fertihzer and micronutrients required by the palm. Long-term studies show that the apphcation of potassium or sodium chlorides in optimum doses as supplements to the standard nutrients for inland farms increases yields in nuts per tree and copra per nut (7, 8). 

Appropriate nutrition for all organisms is a matter of both quantity and balance. For good nutritional health, all of the essential inorganic and organic nutrients must be available, but they must be obtainable in an appropriate balance. A severe shortage of even a micronutrient required in trace quantities can result in severe metabolic dysfunctions, and even death of organisms. 

Among the micronutrients essential for plant growth, molybdenum (Mo) is required in the smallest amounts. In most soils, the Mo requirements of plants can be met by liming the soil. Because of its low requirement, the deficiency and sufficiency concentrations of Mo in most plants are extremely small. Molybdenum toxicity to plants under field conditions seldom occurs, and usually it can be induced only under extreme experimental conditions (Johnson, 1966). Therefore, this chapter does not place great emphasis on the toxic concentrations of Mo in plants. However, plants can, under certain conditions, accumulate large concentrations of Mo and induce molybdenosis in ruminants that eat such material. That will be dealt with in Chapter 15. 

As is evident from Table 9.1, data on Mo deficiencies for many crops are missing, and the data on toxic Mo concentrations in crops are very scanty. Because of the very small requirements for Mo, there appear to be much greater variations in the deficiency and sufficiency concentrations of Mo, as shown by various workers, than for other micronutrients. Some of the differences likely are due to the differing procedures used to determine Mo. The percentage variations seem to be of much larger... 

What are required nutrients Required nutrients are substances that we must include in the diet and those that we keep track of. Sometimes this varies hy area. For example, in the United States, the only macronutrient we typically monitor is protein, as Americans get plenty of carbohydrates and fats. For micronutrients, we keep track of many vitamins and minerals, all of which are required for optimum health. 

Meets animals requirements for nutrients including micronutrients and energy Adequate content Adequate availability High acceptanceAeed intake... 

Iron, like many of the micronutrients, is involved in enzymatic reactions. It is a constituent of cytochrome respiratory pigments found in animals, higher plants and microorganisms. These pigments that are involved in intracellular oxidations, are chemically much like hemoglobin, since they are complexes of iron, porphyrin and a protein. Cytochrome-c and the iron-porphyrin enzyme, cytochrome oxidase, both take part in cell respiration (Hewitt, 1951), and are probably also involved in photosynthesis. Iron is also required for fixation of elemental nitrogen in free-living and nodule bacteria (Nicholas, 1961). 

Cashew nut and its coproducts provide a complex food rich in macronutrients and micronutrients, as well as small quantities of various antioxidants and bioactive compounds that are relevant to many health beneficial attributes. These bioactive compounds include MUFA, PUFA, phenolics, phytosterols, phytostanols, tocopherols, and phytates. While benefits of cashew nut and its coproducts for human health appear promising, further research on bioavailability and bioaccessibility of cashew bioactive compounds as well as potential allergenic reaction is required for a better understanding of the role of cashew nut and its coproducts in human health. 

Micronutrients Micronutrients play an important and sometimes a crucial role in normal plant growth and development. Deficiency symptoms arise in plants that are grown under sub-optimal levels of micronutrients. As such, the tissue culture media are also formulated with the inclusion of essential micronutrients. However, in depth studies of their influence on in vitro cell culture, particularly microspore embryogenesis, are limited. This neglect is in spite of their absolute requirement for many physiological and biochemical cellular processes, including the catalysis of enzymatic reactions. Two of the micronutrients that... 

Most micronutrients require a binder for good adherence on the surface of granular fertilizers. The binder may be oil, wax, water, or fertilizer solution. TVA has developed and studied procedures for coating. A batch method was selected because most bulk blenders in the United States use a batch mixer. The batch method consisted of the followir steps [22] ... 

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