At 78%, this colourless, odourless and tasteless gas (nitrogen) makes up by far the largest proportion in the atmosphere. In agriculture, including viticulture, nitrogen is of eminent importance for photosynthesis and the growth of crops and for fertilising them. However, the huge amount in elemental form(N2 - with two atoms) in the atmosphere hardly plays a role, as only some microorganisms can utilise it directly.
Most plants cannot directly absorb elemental nitrogen in its gaseous form. Instead, they absorb it from the soil in a form that they can utilise and release it again after they die. In the soil, 95% of nitrogen is found in humus formed from dead plant and animal material. However, the organic nitrogen compounds cannot be utilised by higher-value plants.
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