Method for covering iron plaques on root surfaces of water planting root system of wetland plants

Abstract

The invention provides a method for covering iron plaques on root surfaces of a water planting root system of wetland plants. The method comprises the following steps of (S1) preparation of iron plaque inducting liquid: performing anaerobic acidification on anaerobic hydrolysis acidification liquid until the pH (potential of hydrogen) value of the anaerobic hydrolysis acidification liquid is equal to 5 and the oxidation reduction potential of the anaerobic hydrolysis acidification liquid is 450-500, and adding ferrous ions with 100-140mg / L in the anaerobic hydrolysis acidification liquid to form the iron plaque inducting liquid; (S2) tissue culture: placing the root system of the plants in complete culture solution and culturing the root system of the plants for 4-7 days; and (S3) replacing the complete culture solution by using the iron plaque inducting liquid, and culturing the root system of the plants for 5-10 days so as to obtain the plants of which the root surfaces of the root system are coated with the iron plaques. The iron plaques with high phosphorus adsorption capacity can be adhered to the root system of the plants cultured by using the method; and the removal rate of phosphorous in sewage can be increased.

Description

technical field [0001] The invention relates to the field of plant cultivation, in particular to a method for coating the surface of wetland plant roots with iron film. Background technique [0002] The root surface of wetland plants such as rice is often covered with a layer of brown-red iron oxide film, which is called iron film. Its main component is amorphous and weakly crystalline iron oxide. The result of the migration transformation between. Iron is an abundant element in the earth's crust, and wetland soil contains a lot of iron. At the same time, iron is also an active changeable element, which is prone to redox reactions. In the anaerobic zone inside the wetland, the trivalent iron oxide in the soil or matrix particles is absorbed by organic sewage or Small molecular organic acids secreted by plants are catalyzed and reduced to soluble ferrous ions under the action of microorganisms. Ferrous ions migrate to the vicinity of plant roots on the surface of wetlands, a...

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Problems solved by technology

In this way, since only the root part of the plant is immersed in the culture solution, the upper part still needs to be exposed to the air for photosynthesis to maintain activity. Therefore, it is difficult to completely separate the culture solution from the air, and a large amount of oxygen in the air can be dissolved in the culture solution. Because ferrous ions are easily oxidized by dissolved oxygen in the culture solution in the neutral pH range, many ferrous ions are directly oxidized by oxygen in the culture solution and form trivalent iron hydroxide precipitates, and some of them settle on the root surface. Most of it settles at the bottom of the culture solution, and the ferric hydroxide formed by the oxidation of ferrous ions by the oxygen in the water settles on the root surface of the plant. It also looks like an iron film, but it is not firmly bonded to the root and is easily washed away by water. The ferric oxide diffused to the surface of the root cell wall and oxidized by the root releases oxygen to form a relatively firm iron film; moreover, a large amount of ferrous ions are quickly oxidized by oxygen to ferric hydroxide, and at the same time there is a large amount of H + The production of ions causes the buffering capacity of the culture medium to fail, the pH drops rapidly, the roots of the plants are damaged, and the whole plant dies, resulting in the failure of the iron film induction; in order to avoid the oxidation of ferrous ions by the oxygen dissolved in the water, the existing improvement method is to use The culture medium is isolated from the air, and then nitrogen gas is blown into it to blow away the dissolved oxygen to maintain the anaerobic environment of the culture medium. For surface iron film induction, it is necessary to set up more induction systems and provide a large amount of nitrogen, which is expensive and cumbersome to operate. Therefore, better improved methods are still needed for root surface iron film induction.