Method for reducing content of cadmium in rice

Abstract

The invention discloses a method for reducing the content of cadmium in rice. The method includes the steps that in farmland polluted by cadmium, tobaccos are planted in the first half year, and rice is planted in the second half year. A rice planting method includes the following steps that 1, biochar and a soil heavy metal passivant are mixed and scattered on the surface of soil of the farmland polluted by cadmium, then the biochar, the passivant and the soil are mixed to be even, after three days, a base fertilizer is applied, and rice is transplanted, wherein the amount of the adopted biochar is 50-150 kg / hm<2>, and the quantity of the adopted soil heavy metal passivant is 300-6,000 kg / hm<2>; 2, when the rice grows to be in the booting stage, water-solubility leaf silicon fertilizers are sprayed twice, wherein the spraying time interval of the water-solubility leaf silicon fertilizers is 5-7 days, and the quantity of the adopted water-solubility leaf silicon fertilizers is 1,500-6,000 ml / hm<2>. According to the method, the content of cadmium in rice is reduced through the combined effect of the biochar, the soil heavy metal passivant and the water-solubility leaf silicon fertilizers; the biochar serves as an effective component for reducing the content of cadmium in rice, raw materials of the biochar are easy to obtain, and cost is low; the content of cadmium in rice is further reduced through the biochar prepared from tobacco straw and waterflooding management.

Description

technical field [0001] The invention relates to a method for reducing cadmium content in rice, belonging to the technical field of crop food safety control. Background technique [0002] Heavy metals in a broad sense refer to metals with a relative density above 5g / cm3. In the field of environmental pollution, we define heavy metals as metal elements or metalloid elements that are obviously toxic to organisms, such as lead, zinc, copper, cadmium, arsenic, mercury, chromium, nickel, etc. In recent years, with the rapid development of industrial and agricultural production and the improvement of human living standards, the random discharge of industrial "three wastes" and urban domestic sewage garbage, as well as the unreasonable use of pesticides and fertilizers containing heavy metals, have made the content of heavy metals in the soil increase, resulting in ecological and environmental problems such as soil productivity decline, agricultural product pollution, and ecologica...

AI Technical Summary

Problems solved by technology

The consequences of this are firstly that it seriously hinders the sustainable and efficient development of agricultural production, and secondly, after the heavy metals in the soil can be absorbed by plants, they can be enriched in plants, enter the human body through the food chain, and accumulate in the human body without decomposition. Excessive precipitation of heavy metals in the human body can cause headaches, dizziness, insomnia, forgetfulness, joint pain, and even teratogenicity and carcinogenicity.