Soil passivator for planting low-cadmium rice

Abstract

The invention provides a soil passivator for planting low-cadmium rice. The soil passivator is prepared from, by mass, 100 parts of limestone powder, 10-20 parts of ferrous sulfate and 80-120 parts of aluminum industry waste red mud. A preparation method of the soil passivator comprises the following steps: when the raw material red mud is a dry material, theraw material red mud is crushed, and then is directly and uniformly mixed with the limestone powder and the ferrous sulfate to obtain mixed powder; and when the raw material red mud is a water-containing wet material, the raw material red mud is uniformly mixed with the limestone powder, and then ferrous sulfate is added and uniformly mixed. The soil passivator has the advantages that the raw materials are cheap and easy to obtain, the preparation is simple, the soil passivator is used for soil with low cadmium content, the pH value of the soil is properly increased, iron easy to use is provided, formation of root surface iron shells is promoted, the blocking effect of the root surface iron shells on cadmium is exerted, absorption of rice plants on cadmium is reduced, and planting of low-cadmium rice is achieved.

Description

technical field [0001] The invention belongs to the technical field of rice planting, and in particular relates to a soil passivator for low-cadmium rice planting. Background technique [0002] Rice is an important food crop in my country, and the rice produced can be steamed or porridge after husking. [0003] With the development of society and the improvement of living standards, the market for pollution-free rice is getting bigger and bigger. In recent years, frequent grain and food pollution accidents have made people pay more attention to the problem of heavy metal pollution in rice, the most important of which is the content of cadmium and arsenic. [0004] According to the regulations of GB2762-2017 Limits of Pollutants in Food and NY5115-2008 Pollution-free Food Rice, the limit of cadmium in rice is 0.2mg / kg. [0005] The cadmium in rice comes from soil, fertilizer and irrigation water. The cadmium in the soil is not easy to be repaired by removal. Generally, the ...

AI Technical Summary

Problems solved by technology

[0005] The cadmium in rice comes from soil, fertilizer and irrigation water. The cadmium in the soil is not easy to be repaired by removal. Generally, the cadmium in rice and rice is controlled by changing soil conditions, applying barrier agents and passivators, and selecting repellent rice varieties. cadmium content, but often for paddy fields with serious cadmium pollution, the required cost is high or the method is complicated. Under such conditions, it is not economically cost-effective to harvest paddy and rice with cadmium content lower than the above-mentioned 0.2mg / kg

[0006] Among the soil passivation methods used to reduce or control the cadmium content in rice in the prior art, there is a class of low cost and easy to obtain raw materials, such as increasing the pH value of the soil by applying lime or red mud to reduce or control the dissolution of cadmium in the soil And or the absorption of cadmium by rice plants, but because generally higher application rates are required, the alkalinity of the soil increases a lot in a short period of time, and it often takes 10-15 days for the soil pH to return to neutral before fertilization and transplanting , affecting and limiting the utilization of rice fields and the selection of rice varieties

When the application rate of lime or red mud is low, the effect of inhibiting cadmium is not obvious

Images