Describe three ways in which nitrogen becomes available to higher plants?

Question: Describe three ways in which nitrogen becomes available to higher plants?

Nitrogen is an essential nutrient for plant growth and development, but it is often scarce or inaccessible in many ecosystems. Here are three ways in which nitrogen becomes available to higher plants:

- Nitrogen fixation: Some bacteria and archaea can convert atmospheric nitrogen gas (N₂) into ammonia (NH₃) or ammonium (NH₄⁺), which can be taken up by plants or further processed by other microorganisms. Some of these nitrogen-fixing microbes live in symbiosis with plants, such as legumes, and provide them with a direct source of fixed nitrogen.

- Nitrification: Other bacteria and archaea can oxidize ammonia or ammonium into nitrite (NO₂^-) and nitrate (NO₃^-), which are also forms of nitrogen that plants can use. Nitrification occurs in aerobic soils and water, where oxygen is available.

- Decomposition: When plants and animals die, their organic matter is broken down by decomposers, such as fungi and bacteria. This releases nitrogen in various forms, such as amino acids, nucleic acids, urea, and ammonia, which can be recycled by plants or other microorganisms. 

These are some of the major transformations of nitrogen in the environment, but there are also other processes, such as denitrification, anammox, and ammonification, that affect the availability and cycling of nitrogen. Nitrogen is a dynamic and complex element that plays a key role in the biosphere..