A sodium-requiring C(4) plant, Panicum coloratum Walt. cv Kabulabula, was grown with and without sodium. Rate of nitrogen uptake and photosynthesis were measured during the recovery from sodium deficiency. The beneficial effect of sodium on growth was apparent irrespective of nitrogen source, ammonium- or nitrate-nitrogen. The leaf photosynthetic rate ((14)CO(2) fixation) doubled by sodium within 1 hour of the application.