Physical Environment and Symbiotic Nitrogen Fixation II. Root Temperature Effects on the Relative Nitrogen Assimilation Rate

Abstract

Nitrogen fixation by six varieties of Trifolium subterraneum L., each inoculated with a number of strains of Rhizobium trifolii, was examined over a range of root temperatures. Significant differences in the rate of nodule establishment and early nitrogen fixation were found between varieties, and between bacterial strains. In order to minimize the effect of such differences, relative nitrogen assimilation rates (RN) and relative growth rates (R w) were used to compare the different legume-bacteria associations.