Effect of Sewage Sludge on Heavy Metals Accumulation in Soil and Wheat, Mung Bean and Quinoa Crops

Abstract

This study was conducted to study the effects of sewage sludge application to agricultural soil on the heavy metal accumulation in soil and plant and on availability of certain nutrients for plant together with the productivity of wheat, mung bean, and quinoa. The experiment were included four treatments i.e., (Control; inorganic fertilizer according to Ministry of Agriculture-Iraq.; sludge (the amount of sludge containing MoAR recommendation) of N without any addition of mineral N; and twice the amount of sludge without any addition of mineral N) with four replications in the feed crop studies station of the Ministry of Agriculture - Haditha agriculture division located in the village of Sakran (Hasweh Al-Jazeera) of Haditha district 260 km west of Baghdad during the seasons 2017-2018.2019. The applied sludge was described and soil was analyzed prior to cultivation. Upon harvesting, the heavy metals (Cd, Pb, Ni and Cr) were estimated in soil and plant in addition to certain nutrients (Total N, mineral N, available P, macronutrients) and organic matter. About heavy metal in soil and plant, significant buildup of the heavy metal in soil and plant was noticed by increasing the addition of sludge as compared to the control. Significant increase in organic matter and total N of soil in sludge-fertilized treatment was noticed as compared to the control. Moreover, a significant increase in mineral N, available P, Cu, Mn and Zn was also noticed by increasing the addition of sludge. There was significant increasing in plant productivity for various crops during the seasons by increasing the addition of sludge as compared to the control.