Abstract: In order to research the influences of nitrogen reduction combined with soil conditioners on the growth and Cd uptake of rice to provide a scientific basis for Cd pollution paddy field used safely and fertilization reasonably.A field experiment was conducted to investigate the influences of nitrogen reduction combined with the alkaline slow-release fertilize,organic fertilizer and microbial fertilizer on the rice yields and Cd contents in the Cd contaminated paddy soil.The results showed that the rice yields increased by 7.42%(P<0.05), 8.59%(P<0.05) and 4.59% than the contrast with the application of alkaline slow-release fertilize, organic fertilizer and microbial fertilizer respectively. And the rice yields increased by 5.55% and 7.61%(P<0.05),respectively,of the nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer,but the nitrogen reduction 20% with microbial fertilizer decreased the production by 2.48%.So the results suggested that it was feasible to reduce the N fertilizer under this experiment condition.Both the alkaline slow-release fertilizer applied alone or combined with nitrogen reduction 20% could increase the soil pH effectively and decrease the soil available Cd content,and reduced the Cd contents of rice stem and grain efficiently with 31.29% (P<0.05) and 26.58% (P<0.05) than the contrast.Applying of organic fertilizer also increased the soil pH value and reduced the soil available Cd content effectively,and reduced the Cd contents of stem and rice obviously,but there was no evident effect of decreasing of Cd contents in stem and rice when organic fertilizer combined with nitrogen reduction 20%,the Cd content of rice lowered by 31.27%(P<0.05) and 11.96% compared to the contrast when applied organic fertilizer alone and with nitrogen reduction 20%.And the Cd contents of stem and rice had no significant differences compared to the contrast both applied microbial fertilizer alone and with nitrogen reduction 20%.The effect on decreasing Cd content of stem and rice weakened when nitrogen reduction 20% combined with alkaline slow-release fertilizer and organic fertilizer and microbial fertilizer.Overall consideration of the rice yields and the Cd reduction effects of rice and stem,nitrogen reduction 20% combined with alkaline slow-release fertilizer could enhance rice yield as well as reduce Cd content in rice stem and rice,which was applicable for rice production in Cd contaminated paddy soil.

Key words: Nitrogen reduction, Cadmium, Soil conditioner, Alkaline slow-release fertilizer, Organic fertilizer, Rice yield, Heavy metal

CLC Number: 

• S156.2

• X53

• S143.1