Effect of wastewater irrigation on growth and yield of rice crop and uptake and accumulation of nutrient and heavy metals in soil

摘要

Effect of irrigation with untreated and treated wastewater from Vidyaranyapuram sewage treatment plant station on growth and yield of rice as also in enrichment and bio accumulation of nutrients and metals in soil and rice plant in Vidyaranyapuram area in the South West of Mysore, Karnataka was selected. Treatments included untreated wastewater (UWW); treated wastewater (TWW) and ground water (GW) as control. Experimental was in randomized complete block design with 3 treatments with 3 replicates. Soil samples were collected from 0 - 60 cm depths were analyzed for pH, EC, nutrient and heavy metals contents. Plant height, tiller panicle length, number of tillers per plant, weight of 1000 seeds and yield/ plant were used as indicators. The wastewaters according to FAO system of water quality classification were found suitable for use in leaching and irrigating saline soils especially for short duration crops. Great changes in soil properties due to irrigation with UWW and TWW were observed. The growth and yield characters of rice crop were not improved by irrigation with UWW and TWW; however the high concentration of trace metals affected by lowering the growth and yield (number of grains/panicle, weight of 1000 seeds and yield/plant) attributing factors when irrigated by UWW and TWW as compared to GW control. These effects could be attributed to higher accumulation of micronutrients and macronutrients in soil and plant, when the mean values were highly significant as indicated by the present study.