Effects of Combined Application of Cd and Zn in Calcareous Soils on Uptake of P, Cu, Fe and Mn by Two Varieties of Rice in Flooded vs. Nonflooded Conditions

In order to study the effects of variety, water regime, zinc and cadmium levels on concentration, content and translocation of P, Cu, Fe and Mn on rice, a factorial experiment was conducted consisting of four factors including: two varieties of rice (Vandana and Hashemi), two water regimes (flooded and nonflooded), three levels of zinc, and three of cadmium (0, 5 and 10 mg kg-1). The experiment was carried out in a randomized complete block design of three replications. The results showed that from flooded to nonflooded conditions, concentration and content of P in root and shoot, content of Fe in shoot, concentration of Fe in root, concentration and content of Mn in shoot were decreased while concentration of Cu in shoot and root and translocation of Fe being increased. By increase in Zn levels, concentration of P in root and shoot, content of P in root and concentration of Fe in shoot were initially increased but then decreased. By use of Zn, concentrations of Mn and Cu in shoot decreased. Through an increase in Cd level, content of P, Fe and Mn in shoot and root, content of Cu in root were firstly increased, then decreased while concentrations of Fe and Cu in root, concentration of Mn in shoot as well as translocation factor of Mn decreased. The effects of Cd and Zn levels were significant meaning that by use of Cd in any level of Zn, concentration and content of P in root and shoot, content of Cu and P in root, content of Fe and Mn in shoot increased at the start.