Soil treatment method for inhibiting Cd/Pb absorption of rice in contaminated farm land

Abstract

The invention relates to a soil treatment method for inhibiting the Cd / Pb absorption of rice in a contaminated farm land and belongs to the technical field of environmental contamination control and agricultural product quality safety. On a Cd / Pb contaminated land with Cd content of less than 5mgkg<-1> and Pb content of less than 500mgkg<-1>, a biomass carbon soil improvement material is spread on the surface of the contaminated land in an amount of 10 to 40 tha<-1> after harvesting previous crops, and uniformly mixed with soil in a cultivated layer. In the invention, the raw materials are rich, the cost is low, the operation is simple, the Cd / Pb content in brown rice is reduced effectively without influencing yield, and the inhibition effect on the Cd / Pb absorption of rice is remarkable.The biomass carbon soil improvement material is applied in an amount of 40 ton per hectare; and compared with the treatment without applying the biomass carbon soil improvement material, the Cd / Pb content in the rice seeds is reduced by 40 to 50 percent.

Description

technical field [0001] The invention relates to a soil treatment method for suppressing Cd / Pb absorption of paddy rice in Cd / Pb polluted farmland, reducing its grain accumulation and without secondary pollution. technical background [0002] It is estimated that the area of ​​arable land polluted by heavy metals such as cadmium (Cd), arsenic (As), chromium (Cr), and lead (Pb) in China is more than 20 million hectares, accounting for about one-fifth of the total arable land area. Every year, about 10 million tons of grain production is reduced due to soil pollution, and another 12 million tons of grain pollutants exceed the standard. The direct economic loss of the two amounts to more than 20 billion yuan. According to the survey results of the national sewage irrigation area conducted by the Ministry of Agriculture of China, in the sewage irrigation area of ​​about 1.4 million hectares, the area of ​​land polluted by heavy metals accounted for 64.8% of the area of ​​sewage i...

AI Technical Summary

Problems solved by technology

When lime dosage is 1.875 t ha -1 When the Cd content of brown rice is reduced by 30%, it does not reach the "Limits of Pollutants in Food". With the increase of time, the aftereffect of inhibiting Cd uptake by rice is significantly reduced, and the cost is 500-930 yuan per hectare; the amount of silicon fertilizer is 15 t ha -1 When , the Cd content of rice brown rice can be reduced by 78.5% compared with the control, and the Cd content of brown rice can be reduced to 0.41 mg kg -1 , did not meet the "Limits of Contaminants in Food", the cost is 1500-2500 yuan per hectare; the amount of calcium magnesium phosphate fertilizer is 15 t ha -1 , the Cd content of brown rice was 68.91%, reaching 0.15 mg kg -1 , to achieve the "Limits of Pollutants in Food", the cost is 3800-6800 yuan per hectare, but excessive application of calcium magnesium phosphate fertilizer will bring phosphorus pollution, which will bring potential risks of eutrophication of water bodies, and due to cost, benefit and other issues, Difficulty in practical application

Super tired plant restoration takes a long time, usually at least decades, or even hundreds of years. During the restoration, the polluted farmland cannot be used for production, resulting in the waste of cultivated land resources, which does not conform to the actual situation of my country's agriculture.

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