Lead (Pb) and Cadmium (Cd) are a highly toxic elements and are classified as probable human carcinogens.
Both metals can occur naturally in soil at low concentrations but could reach high level in certain areas.
Nitrogen (N) is the mineral element that plants require in the greatest quantity. The accumulation of these metals in plants is shown to be related to N status. Nitrate and ammonium are two major N supply forms which contribute significantly to rhizosphere pH, an important factor regulating metal availability in the environment. Metal toxicity, root morphology and architecture can be affected by the application of different concentrations of nitrate and ammonium.
Hongxin is a visiting PhD student and her work is investigating how management of N sources can be a promising agronomic strategy to reduce metal contamination in crops.