Nitrogen Fixation  /ˈnītrəjən, fikˈsāSH(ə)n/ - noun

March 4, 2020

Definition: The biological process of converting atmospheric nitrogen into compounds that stimulate plant growth.

The decomposition of nitrogen-rich leaf litter and fruit litter plays an integral role in fixing nitrogen to soils. 

Forest Garden Fact: Rooted in agroforestry, the Forest Garden Approach integrates a variety of nitrogen-fixing trees into agriculture and landscapes; a model with proven success among smallholder farmers in low-resource countries.  

Many legumes have a symbiotic relationship with soil bacteria of the genus Rhizobium. These bacteria penetrate a plant's roots; forming nodular swellings on the surface of the root. The biological action takes place in the nodules as the rhizobia absorb the unusable nitrogen gas from the air and in the soil and transform it into useful compounds. 

Did you know? Calliandra calothyrsus is a species used in TREES' programs throughout sub-Saharan Africa. 

Calliandra is a small, versatile tree that can easily integrate into tropical, humid environments.
Like many other legumes, Calliandra can help improve soil quality through the process of nitrogen fixation.

Read about nitrogen fixation and soil on the Forest Garden Training Center's blog