Calcium, magnesium and microelement uptake as affected by phosphorus sources and interspecific root interactions between wheat and chickpea

A glasshouse study was conducted to investigate the effect of supplying phytate and FePO4 and interspecific root interactions on the uptake of Ca, Mg, Fe, Mn and Zn by plants in a mixed culture of wheat (Triticum aestivum L.) and chickpea (Cicer arietinum L.). The pots were separated into two compartments by (i) a solid root barrier to eliminate root contact and solute movement, or (ii) a nylon mesh (30 μm) to prevent root contact but permit solute exchange, or (iii) were not separated into compartments. Wheat plants were grown in one compartment and chickpea in the other. Two P sources, sodium phytate and FePO ₄, were tested at 60 μg P g ^-1 soil. Compared to supplying phytate, supplying FePO ₄ increased concentrations and contents of Ca, Mg, Mn and Zn in wheat and chickpea, and of Fe in chickpea only. When supplied with phytate, intermingling of root systems of the two species increased the content of Ca, Mg, Fe, Mn and Zn in wheat, but reduced the content of Ca, Mg, Fe and Zn in chickpea. When supplied with FePO ₄, root intermingling enhanced the content of Ca, Fe and Zn in wheat, but did not affect the content of Ca, Fe and Zn in chickpea. It is concluded that interspecific root interactions and the form of P supply affect the content of Ca, Fe and Zn in both species. Possible mechanisms involved are discussed.