The stoicheometry of interactions between phosphorus and nutrient cations

Abstract

Various concentrations of Mg, NH₄, and K in the root solution were studied on uptake of radiophosphorus by the root mass, movement to the xylem sap, and accumulation in the top of intact bean plants. Cation levels ranged from 0.02 to 30.0 mM. Potassium had little effect on radiophosphorus in all three measurements, regardless of the level of cation in the root solution. Magnesium and NH4, on the other hand, increased isotope in the root mass, plant top, and xylem sap. Magnesium was more effective in this respect than NH₄. In all cases the increases in radiophosphorus occurred as an asymptote of cation level in the root solution.

Key words:

• Interactions
• stoicheometry