How some trees create their own food

Some plants ‘fix' nitrogen in the soil. Clover is crucial for its role in fixing nitrogen in soil on NZ farms. Tagasaste (tree lucerne, Chamaecytisus palmensis) is a highly nutritious fodder tree that also fixes nitrogen. Nitrogen-fixing plants and trees partner with soil microbes, turning atmospheric nitrogen gas into a form of nitrogen available to plants to use for growth. 'Fixers' also help return nitrogen to the soil when they drop their leaves. Research has found the presence of trees that fix nitrogen could double the amount of carbon a forest stores in its first 30 years of regrowth. At maturity, forests with nitrogen fixers capture up to 10% more carbon dioxide than forests without them. Source: Cary Institute of Ecosystem Studies