How do plants absorb nitrogen from the soil?

Plants primarily absorb nitrogen from the soil in the form of nitrate ions because this form is readily available and easily assimilated by most plants. Nitrates are highly soluble in water, making them accessible to plant roots during uptake. After being converted from atmospheric nitrogen through processes such as nitrogen fixation and nitrification, they are available in the soil for plants to take in.

Nitrate ions play a crucial role in the synthesis of essential compounds such as amino acids and proteins, which are vital for plant growth and development. This process is essential for plants to thrive, as nitrogen is a key nutrient that facilitates various physiological processes.

While ammonia is another form of nitrogen that plants can absorb, its uptake is less common compared to nitrates due to the potential toxicity of ammonia at higher concentrations. Nitrite ions, on the other hand, are usually an intermediate in the nitrogen cycle and are less commonly used by plants directly. Nitrogen gas, while abundant in the atmosphere, cannot be absorbed by plants directly and must first be converted into a usable form through processes like nitrogen fixation carried out by specific bacteria.