Efficiency of Rice Straw and Its Different Composts in Remediation of Cd and Pb Contaminated Sandy Loam Soil

Abstract

Remediation of heavy metals contaminated soils is necessary to reduce heavy metals availabilities and their uptake by crops. Development of cost-effective amendments is still a very important task in the soil environmental system for decreasing hazardous of heavy metals, and improving soil quality and crop production in low fertile and polluted soils. A pot experiment was carried out to determine the efficiency of rice straw (RS), rice straw compost (RSC) and rice straw-farmyard manure compost (RSFC) at three rates (0.25, 0.50 and 1%) in the amelioration of Cd and Pb polluted loamy sand soil. Faba bean plant was selected to be as an indicator plant in this experiment. The addition of RS, RSC and RSFC caused significant increases in soil chemical properties such as soil pH, organic matter (OM) and available phosphorus (AP). Application of RS, RSC and RSFC led to high reductions in soil available Pb and Cd contents. Availabilities of Pb and Cd were highly affected by soil chemical properties. Incorporation of RS, RSC and RSFC improved the growth of bean plants and decreased accumulations of Cd and Pb in their straw, roots and seeds. Absorptions of Cd and Pb were significantly decreased with increasing rates of RS, RSC and RSFC. The greatest seed yields of bean (5.12 and 6.00 g pot-1) were noticed at 1% RSC and 1% RSFC, respectively. Our study suggests that RS, RSC and RSFC are suitable organic amendments to improve fertility and quality of the chosen heavy metals contaminated sandy loam soil.