Influence of nickel-contaminated soils on fenugreek ( Trigonella corniculata L.) growth and mineral composition

Abstract

Leafy vegetables accumulate higher amount of heavy metals like nickel (Ni) due to their more leafy vegetative growth. Therefore, a screenhouse experiment was conducted using an alkaline sandy loam soil equilibrated with graded levels of Ni (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250 and 300 mg kg −1 soil) to assess the Ni accumulation pattern and its influence on growth and micronutrient distribution in fenugreek plants. Green as well as the dry matter yields of fenugreek increased slightly up to 20 g Ni kg −1 soil but decreased significantly with the application ≥40 mg Ni kg −1 soil. Crops showed characteristic toxicity symptoms of interveinal chlorosis in pots receiving ≥40 mg Ni kg −1 soil. While the total content of Ni in the plant tissues increased consistently with increasing rates of applied Ni, the roots accumulated much higher amount of this element compared to the shoot. The content of Fe in plants showed an increase whereas that of Cu and Zn experienced a decrease with the rise in the applied Ni.