Effects of irrigation with treated and untreated wastewater on nutrient, toxic metal content, growth and yield of coriander (Coriandrum Sativum L.)

Abstract

The study was conducted in Vidyaranyapuram area in the South West of Mysore, Karnataka. It was aimed to investigate the concentration of macronutrients and trace metals of arable soils and to compare by those irrigation with wastewater on soil and coriander plant ( Coriandrum sativum L.), grown during its growth period. Twenty one samples each of water, soil and coriander plant were collected from different sites. Treatments included untreated wastewater (UWW); treated wastewater (TWW) and ground water (GW) as control. The used water sources when evaluated as irrigation water according to the FAO system of water quality classification were found suitable for use in leaching and irrigating the saline soils especially for short duration crops. The results indicated that use of wastewater for irrigation led to significant differences in mean values of pH, EC, N, P, Ca, Mg, Na, Mn, Cu, Zn, Cd, Ni, Pb and Cr of soil as compared to the control GW irrigated soil sample. N, P, K, Ca, Mg and Na contents also increase in leaves of coriander crop significantly higher than the GW irrigated control plants, irrigation with different proportions of wastewater showed significantly higher concentrations of heavy metals like Fe, Mn, Zn, Cu, Ni, Pb and Cr in leaf tissues of coriander crop, except for Cd and Co, as compared to the control treatment GW. The results indicated that irrigation of coriander with UWW and TWW affect negatively on growth and yield parameters of coriander; these effects could be attributed to accumulation of micronutrients and macronutrients in soil. These results suggest that UWW and TWW effluents of Vidyaranyapuram area not fit for be utilization as a important sources of water for irrigating coriander crop, as they show it did have significant harmful effects on crop productivity.