how is nitrogen use in the rhizosphere

In the rhizosphere, nitrogen is actively cycled by plants and microbes. Nitrogen-fixing bacteria convert atmospheric N₂ to plant-available ammonium. Others perform nitrification, ammonification, or denitrification. Plant roots release organic compounds that stimulate microbial mineralization of nitrogen. Rhizosphere microbes can also immobilize nitrogen temporarily, regulating its availability. Competition between microbes and roots is intense, especially under limited nitrogen supply.