Lämmastamisel

Lämmastamisel, also known as nitrogen fixation, is a biological process where atmospheric nitrogen (N₂) is converted into ammonia (NH₃) or related nitrogenous compounds. This process is essential for making nitrogen available to plants and other organisms, as atmospheric nitrogen is generally unavailable in its diatomic form. Lämmastamisel occurs naturally through both biological and physical means, as well as industrially.

Biological nitrogen fixation is primarily carried out by certain bacteria and archaea, either freely living in the soil or in symbiotic relationships with plants. Leguminous plants, such as peas, beans, and clover, host nitrogen-fixing bacteria called rhizobia in their root nodules. These bacteria convert atmospheric nitrogen into ammonia, which the plant can then use to synthesize amino acids and other nitrogen-containing compounds. Non-leguminous plants may also associate with nitrogen-fixing bacteria, such as those in the genus *Azotobacter*, though these relationships are less common.

Physical nitrogen fixation occurs naturally through processes like lightning, which produces high temperatures and pressures that split nitrogen molecules, allowing them to combine with oxygen to form nitrates. These nitrates are then carried to the soil by rain. Industrial nitrogen fixation, on the other hand, is carried out through the Haber-Bosch process, which synthesizes ammonia from nitrogen gas and hydrogen under high pressure and temperature, using a catalyst. This process is crucial for producing fertilizers to support modern agriculture.

Lämmastamisel is vital for maintaining soil fertility and supporting plant growth. Without it, nitrogen—a key nutrient for proteins and nucleic acids—would be largely inaccessible to most organisms, limiting biological productivity. Both natural and artificial methods of nitrogen fixation play important roles in sustaining ecosystems and agricultural productivity.