Average nitrogen fixation rate by rhizobium associated with leguminous forages (e.g., alfalfa, clover)

Range 10,000 - 20,000 mg N/m^2/yr
Organism Biosphere
Reference Galloway et al., Nitrogen Cycles: Past, Present, and Future, Biogeochemistry September 2004, Volume 70, Issue 2, pp 153-226 p.155 3rd paragraph
Primary Source Smil V. 1999. Nitrogen in crop production: an account of global flows. Global Biogeochem. Cycles 13: 647–662.
Comments "The annual per-area rates of transfer of atmospheric N2 to Nr (reactive nitrogen) by cultivation can be large compared to natural rates of transfer. As thoroughly reviewed by Smil (primary source), Rhizobium associated with seed legumes (e.g., peas and beans) can fix N at rates ranging from 3X10^2 to 3X10^4 mgN/m^2. Most fixation rates are on the order of 4X10^3 to 3X10^4 mgN/m^2. Rhizobium associated with leguminous forages (e.g., alfalfa, clover) have higher average rates, 1X10^4 to 2X10^4 mgN/m^2."
Entered by Uri M
ID 110426