Effects Of Modifier Combined With Water Management On The Absorption And Accumulation Of Cadmium In Rice

In order to explore the application value of three modifiers(Xiang Runbang soil conditioner,silicon fertilizer,gypsum powder)in soils with different cadmium(Cd)pollution degree,this paper selects three different Cd pollution levels in Zhuzhou City,Hunan Province.The soil(very heavily polluted soil,heavily polluted soil and moderately polluted soil)was tested in a pot experiment to explore the effect of three amendments on the reduction of available cadmium content in soil and the reduction of cadmium content in various parts of rice,and to analyze the combination of three modifiers.The combination of flooding measures and single improver treatment.This paper also compares the effect of improving agent combined with flooding treatment and single modifier treatment on soil available cadmium content and cadmium content in all parts of rice.This paper aims to provide scientific basis and technical support for the safe use of medium and heavy cadmium contaminated cultivated land in Hunan Province.The main test results of this paper are as follows:1.The pot test shows:(1)Xiangrunbang soil conditioner,silicon fertilizer treatment,gypsum powder treatment,flooding treatment,improver combined flooding treatment and comprehensive treatment can all reduce the effective cadmium content in soil and cadmium content in various parts of rice.Among them,the comprehensive treatment effect of the three modifiers combined with flooding is the best,followed by the single modifier + flooding treatment,and then the single modifier treatment.The flooding treatment is worse than the single modifier treatment.(2)The soil conditioner,silicon fertilizer treatment and gypsum powder treatment of Xiangrun State can reduce the cadmium content of various parts of rice,and can make the cadmium content of rice in moderately cadmium-contaminated farmland reach the national food safety standard,but there is still a risk of exceeding the standard;Reduce the cadmium content of brown rice in cultivated land with extremely severe cadmium pollution by 42%-76.57%.(3)The effect of improving agent combined with flooding treatment on reducing cadmium content in various parts of rice is higher than that of single improving agent treatment.For brown rice,the reducing rate of improving agent treatment on brown rice cadmium content is between 26.09%-38.46% The reduction rate of cadmium content of brown rice between modifiers and flooding measures is between 54.78%-70.19%,and the reduction rate of cadmium content of brown rice by comprehensive treatment is between77.88%-78.26%.2.The test results of the field plot showThe comprehensive results show that the three modifiers,whether single application or improved agent combined with flooding treatment,are best treated with silicon fertilizer(basic application + foliar application),followed by Xiangrunbang conditioning agent and gypsum powder.