Shoot-Root-Nodule Partitioning in a Vegetative Legume--A Model

A dry-matter partitioning model of a vegetative legume whichis both utilizing nitrate nitrogen and carrying out N₂ fixationis described. It is an extension of a previously described root-shootmodel, and is based on assumed transport pathways for carbonand nitrogen substrates, and utilization of those substratesfor structural growth. The model is used to examine the consequencesof varying the photosynthetic activity, the nitrate uptake activity,and the N₂ fixation activity on the patterns of dry-matter partitioningand substrate fluxes within the plant. The predictions of themodel agree with physiological expectation, and the model cantherefore be used to provide an interpretation of experimentalobservations of such plant and crop responses. Model, partitioning, legume, nitrogen fixation