In order to understand the interaction effects ofhum ic acid and paddy-upland rotation on rice quality in cadm ium contam inated soil,a potexperim entw as setup in the m ethod ofrandom block design,hum ic acid w as 0,0.1,1 and 10 g/m 2 m eterin tw o kinds ofsoilw ith paddy-upland rotation,the contentofcadm ium in brown rice w ould be determ ined afterharvest,the contents ofm icroelem ents ofiron,zinc, magnesium and calcium in brown rice w ould be determ ined in the m eantim e.The results show ed thatw ith increasing hum ic acids in the tw o kinds ofsoils ,the contentofcadm ium in brown rice an...