Effectiveness of liming to minimise uptake of cadmium by wheat and barley grain grown in the field

Abstract

The effects of soil pH on cadmium (Cd) concentration in wheat and barley grain were determined from 8 field experiments in the Rutherglen (Victoria) and Wagga Wagga (New South Wales) regions of south-eastern Australia. Generally, raising soil pHc, from 4.0 to 5.0 using lime decreased Cd concentration in the grain. However, the response was variable between sites and years, with the greatest variation occurring between years. At those sites where there were statistically significant decreases in Cd concentration with increasing pH, the rate of decrease was small. The Cd concentration exceeded the maximum permissible concentration (MPC) of 0.05 mg/kg in barley grain at 3 sites and in wheat at 1 site. In some cases, raising soil pHCa, to 6.0 was not sufficient to decrease Cd concentration in grain below the MPC and raising soil pH above this value would not be considered economically viable in many areas.