Methods for Evaluating Nitrogen Fixation by Nodulated Legumes in the Field

Abstract

It is intended that this publication will complement the many books and review articles that deal with the various technologies associated with symbiotic N2 fixation.In particular, the principles behind xylem-solute techniques, N-difference procedures, and 15N isotope dilution methods for quantifying Nz fixation will be described.The application of these techniques in the field will be discussed as will the analysis and interpretation of experimental data.In each section the reader is provided with references to the most relevant literature citations for additional detail.Much of the text will refer to studies of food legumes, although the general concepts can also be applied to other legume systems.Similar methodologies eN-difference, 151\) are also utilised in studies of associative N2 fixation with non-legumes; readers are referred to a comprehensive review of tills topic by Boddey (987).