Yield and uptake response of lettuce to cadmium as influenced by nitrogen application

Abstract

A screen house experiment was conducted to determine the effect of N (0, 50, 100 and 150 mg N kg−1) and Cd (0, 5, 10, 25 and 50 mg Cd kg−1) on growth and concentration and uptake of N and Cd in lettuce grown for 70 days. Nitrogen application increased significantly fresh yield, dry matter yield, N concentration and uptake, whereas these parameters were significantly decreased by Cd application at all levels of N. The concentration and uptake of Cd were significantly increased by Cd application at all levels of N. This increased Cd uptake was related to increased availability of Cd in soil. Application of N upto 100 mg N kg−1 increased Cd uptake, whereas there was sharp reduction in Cd uptake at 150 mg N kg−1 treatment at all levels of Cd. The plant dilution effects and reduced translocation of Cd from roots to tops or the competition at the root absorption sites at highest level of N seem to be the mechanisms responsible for N suppressed Cd uptake in this study.