Excretion from Leguminous Root Nodules

Abstract

VIRTANEN^1,2, using pea, vetch and clover, has amply confirmed the suspicion of some earlier workers by showing that under certain conditions (for example, in sand culture) there is an excretion of fixed nitrogen in the form of amino-acids from the nodules of these plants into the rooting medium. It does not follow that this finding may be extended to leguminous plants in general. In experiments carried out as an extension of published work³, and with the assistance of Mr. I. W. Prentice, I have been unable, by analysis of the rooting medium, to find evidence of excretion of fixed nitrogen from the nodules of soya bean plants at any stage in development, although extensive fixation occurred within the nodules. The plants were grown in open sand-cultures, initially sterile.