In-situ chemical imaging method and system for soil earthworm drilosphere

An in-situ chemical imaging method for soil earthworm drilosphere, comprising:

• S1, preparing an earthworm box and filling the earthworm box with soil meeting requirements;
• wherein the soil has a moisture content of 60% to 70% of field water capacity;
• S2, selecting suitable earthworms, placing the earthworms in the soil within the earthworm box, and cultivating for a period of time to allow formation of sufficient earthworm pores in the soil;
• wherein the earthworm box has a square box structure, comprising a removable acrylic front plate (1), a removable acrylic top plate (2), and an earthworm box rear portion (4);
• the removable acrylic front plate (1) is fixed to the earthworm box rear portion (4) via front plate screws (101);
• the removable acrylic top plate (2) is fixed to the removable acrylic front plate (1) and the earthworm box rear portion (4) via top plate screws (201);
• and a top wall of the earthworm box rear portion (4) is provided with earthworm box top screw holes (402), and top plate screw holes (203) are connected and fixed to the earthworm box top screw holes (402) via the top plate screws (201);
• wrapping peripheral sides, top, and bottom sides of the earthworm box with aluminum foil;
• S3, sequentially arranging a filter membrane, a diffusive gradients in thin-films (DGT) binding gel, and a potential of hydrogen (pH) planar optode membrane on a soil profile of the earthworm drilosphere to be imaged, enabling the filter membrane, the DGT binding gel, and the pH planar optode membrane to fully adhere to the soil profile of the earthworm drilosphere, applying ultraviolet light to the earthworm box under light-proof conditions, cultivating for a period of time, and capturing fluorescence signals emitted by the pH planar optode membrane using an imaging device to obtain a pH fluorescence image;
• wherein a certain amount of deionized water is supplemented between the pH planar optode membrane and the soil profile of the earthworm drilosphere to ensure no bubbles exist therebetween, and a soil system is allowed to stand for at least 5 minutes after supplementing the deionized water to achieve complete stability of the soil system;
• S4, performing a color development reaction on the DGT binding gel to obtain a color-developed DGT binding gel;
• and
• S5, capturing a color image of the color-developed DGT binding gel using a flatbed scanner to obtain a DGT image, and performing image processing on the DGT image and the pH fluorescence image obtained in S3, to obtain spatial distribution images of labile phosphorus and pH in the earthworm drilosphere.