Effects of blended amendment（biochar + lime）on pH，available Cd in paddy soiland，Cd content in brown rice

A blended amendment was prepared by mixing biochar and lime（BL） at a mass rate of 10:1. In order to study the effects of application of the BL on remediation of heavy metal Cd contaminated paddy soils，a field experiment was conducted near a mining area in northern Guangdong province. The results showed that the BL increased soil pH by 0.53，decreased soil available Cd by 24.14%，and decreased the Cd content of brown rice by 53.12%（P ＜ 0.05）. There were significantly negative linear correlations between the soil pH and the available Cd in soil，and significantly negative linear correlations between the soil pH and the Cd contents in brown rice（P ＜ 0.05）. Meanwhile，the available Cd in soil had significantly positive linear correlation with Cd content of brown rice（P ＜ 0.05）. The BL treatment could decrease Cd content in brown rice to the limits（0.2 mg/kg） of the National Standard GB 2762-2012. The study indicated that BL was a high-effective material on the remediation of paddy soil contaminated by heavy metal Cd.