Effect of industrial effluent on soil properties, essential nutrient and pollutant element status of soils and plants in a vegetable growing near Jajmau industrial area of Kanpur, Uttar Pradesh, India

Abstract

Effect of continuous irrigation with industrial effluent for more than three decades on soil physical, physico-chemical properties; and major, secondary and micronutrient with pollutant element status of soils and plants in Jajmau area of Kanpur city of Uttar Pradesh was ascertained. Long term alone use of industrial effluent for growing crops, particularly vegetables, may result in the uptake of toxic metals by crop plants, with the chance of their access into the food chain. While the use of industrial effluent with alternate irrigated with well water, the physical properties of soils were observed to be improved. An appreciable increase in organic carbon; available N, P, K and micronutrients were recorded in the alternate with industrial effluent and well water irrigated soils over that of the alone Industrial effluent irrigated soils. Electrical conductivity of alternate irrigated soils was much below the threshold limit of salinity. Long-term application of industrial effluent water resulted in the accumulation of heavy metals in surface soil; the concentration of these elements is approaching the maximum permissible limits suggested. The mean content of total Fe, Mn, Zn, Cu, Ni, Cr and Pb in the soils irrigated with industrial effluent water was 1.53, 1.09, 1.12, 1.14, 1.01, 1.23 and 1.01 times as compared to their content in the alternate irrigated soils, and the concentration of these metals in sugar beet grown on industrial effluent-fed soils was higher by 1.34, 1.16, 1.32, 1.51, 1.34, 1.65 and 1.26 times, respectively. The relative availability of the metals was recorded in the order of Pb > Cu > Zn > Mn > Cr > Ni > Fe. The concentration of heavy metals in sugar beet plant grown on industrial effluent was higher as compared to their tolerance level indicating their accumulation in plants. The results suggest that industrial effluent irrigation improves soil physical properties and fertility status indicating its potential for use in agriculture. However, accumulation of heavy metals in soil and plant necessitates its safer use of alternate industrial effluent with well water to safeguard soil health and reduce the risk of animal and human health hazard. Sugar beet was found more suitable in comparison to other vegetables under study and can be used for phytoremediation purposes to minimize the concentration of heavy metals in soil.