Nitrogen Fixation by Woody Plant Species as Measured by the Acetylene Reduction Assay1

Abstract

Nodules from 13 woody plant species were analyzed by an acetylene reduction assay to determine their nitrogen fixation activity. Acetylene reduction activity was found with nodules from Alnus glutinosa (L.) Gaertn., Caragana arborescens Lam., Elaeagnus angusti/olia L., E. umbellata Thunb., Hippophae rhamnoides L., Myrica pensylvanica Lois, Robinia fertilis Ashe., R. hispida L., R. pseudoacacia L., Shepherdia argentea Nutt., and S. canadensis Nutt. In addition, nodules from A. glutinosa were found to reduce acetylene for at least 9 hours after having been excised from the plant No active nodules were found on Comptonia peregrina (L.) Coult. or Cercis canadensis L.