Plants also utilize some gaseous elements (C, H and O) taken directly from atmosphere.
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Woodward (1699) : Plants obtain minerals from soil through root system.
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Liebig (1840) : Source of carbon in the plant is CO2 obtained from the atmosphere.
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Arnon and Stout (1939) : Criteria for essentiality of elements
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The plant is unable to grow normally and complete its life cycle, in the absence of the elements.
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The element is specific and cannot be replaced by another element.
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The element plays a direct role in the metabolism of the plant.
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Plant ash (obtained heating the dry plant part at 600°C) contains oxides and carbonates of elements.
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About 92 mineral elements present in different plants; 30 in each and every plant.
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Of these 30 elements, 16 elements are necessary for plant growth and are called essential elements, rest non essential elements.
