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 All plants whether autotrophic or heterotrophic require mineral nutrition for growth and metabolism. |
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The parasitic plant, cuscuta has haustoria to derive nourishment from the host plant. |
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A plant needs many essential nutrients for a healthy growth. They could be macro elements (required in large quantity) or microelements (required in traces). |
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By using the water culture technique or soil-less culture, it is possible to ascertain the importance of particular minerals. |
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Some elements are structural components while others are co-factors of several enzymes. They are required in various metabolic pathways and so the deficiency results in stunted growth, chlorosis, necrosis or other specific symptoms. |
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NPK are the three basic nutrients essential for plant growth. |
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The minerals are taken up by the roots through passive or active absorption. |
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Nitrogen, an essential nutrient cannot be taken in by the plants unless fixed into various compounds. |
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Nitrogen fixation is primarily by symbiotic bacteria - Rhizobium or by free living cyanobacteria. |
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For nitrogen fixation, a large amount of energy is derived from ATP molecules. |
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The dinitrogen molecule is reduced to ammonia with the help of enzyme nitrogenase. |
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The nitrifying bacteria convert ammonia to nitrites and then to nitrates, which are more suitably absorbed by the plants. |
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After the nitrates are absorbed, they are converted to ammonia with the help of nitrate reductase and nitrite reductase. |
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The fertilizers increase the fertility of the soil and hence are essential for the healthy growth of the plant. |
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NPK fertilizers are the most common fertilizers used for the crop plants. |
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