Interactive Effect of Nitrogen and Phosphorus on Rice Fe, Zn, and Mn Uptake under Continuous submergence and intermittent saturation

In this research، the effects of variety، water regimes، nitrogen and phosphorus on the concentration، content، and translocation factor of iron، zinc، and manganese in rice was studied in greenhouse conditions in a calcareous soil. This factorial experiment was done in a randomized complete blocks design with three replicates. The factors included two varieties of rice (Hashemi and Ali Kazemi)، water regimes at two levels (continuous submergence and intermittent saturation)، N at three levels (0، 75، 150 mg kg-1) as urea، and P at three levels (0، 25، 50 mg kg-1) as mono calcium phosphate. Having completed 90 days، plants were harvested and total content and concentrations of Fe، Mn and Zn in shoot and root were measured. According to the results، N application caused an increase in Fe concentration of shoot (the above-ground parts)، but caused a decrease in Zn and Mn concentration. However، N application caused an increase in Fe، Zn، and Mn content of shoot. P application caused a decrease in Fe and Zn concentration of shoot، but caused no significant change in Mn concentration of shoot. Also، P application caused a decrease in Fe، Zn، and Mn content of shoot. The result showed that Zn concentration in root and Fe concentration in shoot of Hashemi variety was greater than in Ali Kazemi variety. Fe، Mn، and Zn concentrations in shoot and root in flooded conditions were greater than in periodic saturation. In this research conditions، the content of Fe in shoot and root of both cultivars were not significantly different، but the content of Fe in the shoot and roots of the continuous flooded conditions were greater than the intermittent saturation. In the case of Zn content in shoot and root، there were no significant difference between the two varieties، but the Zn content of shoot was greater under the continuous submergence than in intermittent saturation. Interactions between nitrogen and phosphorus had significant effect on Zn، Fe، and Mn concentrations of shoot and root. Translocation factor of Zn in Hashemi variety was greater than Ali Kazemi variety، but، in the case of Fe and Mn، difference in the translocation factor between the two varieties was not significant. In this experimental condition، translocation factor of Mn was greater than that of Zn and Fe.