Effects of heavy metals concentration of irrigation water from different sources on the contamination of paddy field soil

The quality of water is as important as its quantity in irrigation. Lack of wastewater purification plant in Rasht, Zarjoub River receives all municipal, industrial and agricultural wastewaters. In this study the effects of irrigation water from five stations along the river and irrigation water from well water on heavy metals accumulation in soil were assessed. A pot experiment was carried out in a completely randomized design with three replications. Irrigation regimes were flooding, saturated condition, field capacity (FC), 0.8FC and 0.6FC. Irrigation was done with water from five stations along the river and water from a well. After physiological maturity, harvest was done and soil heavy metals concentrations were measured with atomic absorption apparatus. Results showed that pot soils in all treatment were polluted with Cd and Cu (being in average higher than 0.3 and 50 mg/kg as maximum allowable concentrations, respectively) however Pb and Zn pollutions were not detected (being in average higher than 250 and 200 mg/kg as maximum allowable concentrations, respectively).