[Effects of alkaline fertilizer on cadmium content in rice and paddy soil.]

A field plot trial was conducted at Songbai Village, Chenzhou, Hunan Province to exa-mine the effects of alkaline fertilizer with and without combination application of bacterial regent on cadmium accumulation in rice and paddy soil. Compared with the conventional fertilizer, the alkaline fertilizer reduced the available cadmium content in soil at the tillering, filling and the harvest stages by 8.3%, 6.7% and 16.4% respectively. Compared with the Cd content in soil before transplanting, it was reduced by 7.2% at harvest time in alkaline fertilizer treatment, while increased by 11.0% in the conventional fertilizer treatment. The available cadmium content in soil was increased by 1.2% to 23.3% by bacterial regent. Compared with the conventional fertilizer, the cadmium content of root, stem sheath, leaf, grain and brown rice of the alkaline fertilizer treatment reduced by 54.9%, 56.6%, 41.8%, 62.7% and 67.6% respectively. The alkaline fertilizer treatment combined with bacterial regent increased the cadmium content of brown rice by 63.2%. It was concluded that the alkaline fertilizer could significantly reduce the available cadmium content in both soil and the different organs of the rice, however, when it was combined with bacterial regent together, the effect of alkaline fertilizer to reduce Cd content of brown rice would be declined.