Immobilization of cadmium in soil by cow manure and silicate fertilizer, and reduced accumulation of cadmium in sweet basil (Ocimum basilicum)

Abstract

This study was conducted to determine the effects of organic and inorganic soil additives in reducing Cd concentration in the edible parts of plants. A pot study was performed by growing Ocimum basilicum (sweet basil) in Cd contaminated soil (20 mg/kg Cd) and soils amended with cow manure and silicate fertilizer for 3 months. The results showed an increase in dry biomass production by factors of 4.7 and 1.7 in plants grown in soil supplemented with cow manure (20% w/w) and silicate fertilizer (20% w/w), respectively. Shoot Cd accumulation doubled in plants grown in cow manure treated soil. In contrast, the silicate fertilizer resulted in a 3-fold decrease in leaf Cd accumulation. The results of this investigation demonstrated the potential of silicate fertilizer in reducing Cd transport from roots to shoots, resulting in decreased Cd concentration in the edible parts of plants.