Minerals in plants

Growth can be defined as the production of organic matter by increase in size or volume. This process involves the uptake of water, carbon dioxide and minerals. In plants, growth is made possible by the process of photosynthesis, which produces the sugars (as primary components) from which compounds such as starch, cellulose, amino acids and proteins are derived. 

Some elements appear in plant and animal products at relatively constant levels, but in a number of cases an abundance of a certain element in the environment may result in a greatly increased level of that mineral in plant or animal products. Enrichment of elements in a biological chain may occur note, for instance, the high mercury levels reported in some large predatory fish species such as swordfish and tuna. 

Boron is also an essential trace mineral in plants. A trace mineral is an element needed in minute amounts for the good health of an organism. Boron is critical to production of certain essential plant proteins and to help plants extract water from the soil. Low levels of boron show up as yellowing, blackening, twisting, or crumpling of leaves. 

Webster defines the term mineral as any chemical or compound occurring naturally as a product of inorganic processes. Since this chapter is primarily concerned with the use of minerals in plant and animal nutrition, terms such as plant nutrients , trace elements , fertilizer nutrients , and mineral additives are used within the context of Webster s definition, including inorganic fertilizers derived from naturally occurring minerals. 

A20. Evans, H.J. and S. Russell The role of minerals in plant metabolism and the relationship of mineral nutrition to plant composition University of Kentucky Tobacco and 20A36. 

It occurs in the minerals rutile, ilmenite, and sphene, and is present in titanates and in many iron ores. Titanium is present in the ash of coal, in plants, and in the human body. 

Calcium. Soil minerals are a main source of calcium for plants, thus nutrient deficiency of this element in plants is rare. Calcium, in the form of pulverized limestone [1317-65-3] or dolomite [17069-72-6] frequendy is appHed to acidic soils to counteract the acidity and thus improve crop growth. Such liming incidentally ensures an adequate supply of available calcium for plant nutrition. Although pH correction is important for agriculture, and liming agents often are sold by fertilizer distributors, this function is not one of fertilizer manufacture. 

Potassium [7440-09-7] K, is the third, element ia the aLkaU metal series. The name designation for the element is derived from potash, a potassium mineral the symbol from the German name kalium, which comes from the Arabic qili, a plant. The ashes of these plants al qili) were the historical source of potash for preparing fertilisers (qv) or gun powder. Potassium ions, essential to plants and animals, play a key role in carbohydrate metaboHsm in plants. In animals, potassium ions promote glycolysis, Hpolysis, tissue respiration, and the synthesis of proteins (qv) and acetylcholine. Potassium ions are also beheved to function in regulating blood pressure. 

Zinc, like most metals, is found in all natural waters and soils as well as the atmosphere and is an important trace element in plant and animal life (see Mineral nutrients). Rocks of various kinds contain 20—200 ppm zinc and normal soils 10—30 ppm (average ca 50 ppm) in uncontaminated areas. The average zinc content of coal is 33 ppm. Seawater contains 1—27 )-lg/L (median ca 8 p.g/L), and uncontaminated freshwater usually <10 / g/L. 

Copper is one of the twenty-seven elements known to be essential to humans (69—72) (see Mineral nutrients). The daily recommended requirement for humans is 2.5—5.0 mg (73). Copper is probably second only to iron as an oxidation catalyst and oxygen carrier in humans (74). It is present in many proteins, such as hemocyanin [9013-32-3] galactose oxidase [9028-79-9] ceruloplasmin [9031 -37-2] dopamine -hydroxylase, monoamine oxidase [9001-66-5] superoxide dismutase [9054-89-17, and phenolase (75,76). Copper aids in photosynthesis and other oxidative processes in plants. 

Some plants have been using computer control for 20 years. Control systems in industrial use typically consist of individual feedback and feedforward loops. Horst and Enochs [Engineering h- Mining]., 181(6), 69-171 (1980)] reported that installation of single-variable automatic controls improved performance of 20 mineral processing plants by 2 to 10 percent. But interactions among the processes make it difficult for independent controllers to control the circuit optimally. 

Biological and volcanic activities also have roles in the natural mobilization of elements. Plants can play multiple roles in this process. Root growth breaks down rocks mechanically to expose new surfaces to chenaical weathering, while chemical interactions between plants and the soil solution affect solution pFF and the concentration of salts, in turn affecting the solution-mineral interactions. Plants also aid in decreasing the rate of mechanical erosion by increasing land stability. These factors are discussed more fully in Chapters 6 and 7. 

Jouanneau Y, JC Willison, C Meyer, S Krivobok, N Chevron, J-L Bescombes, G Blake (2005) Stimulation of pyrene mineralization in freshwater sediments by bacterial and plant augmentation. Environ Sci Technol 39 5729-5735. 

S. E. Smith, G. Rosewarne, S. M. Ayling, S. Dickson, D. P. Schachtman, S. J. Barker, and F. A. Smith, Mycorrhizal involvement in plant mineral nutrition a molecular and cell biology perspective. Plant Nutrition—Molecular Biology and Genetics (G. Gissel-Nielsen, and A. Jensen, eds.), Kluwer Academic, Dordrecht, 1999. 

Fresh organic matter plays a fundamental role in plant nutrition by supplying nutrients released through degradation processes however, humified organic substances also become a source of nutrients when subjected to mineralization processes. The main aspects of the cycle of organic matter at the rhizosphere soil are reported in Chap. 6. 

Mineralization and immobilization in the rhizosphere are processes that are probably suitable to enable us to estimate ecosystem performance—e.g., productivity, stability, resilience. To properly answer this question, we should understand how differences in plant species may affect below-ground subsystems and what is the functional significance of diversity of. soil organisms. 

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