Herbicide for potato fields and preparation method thereof

The invention relates to the field of pesticides, in particular to a herbicide for potato fields and a preparation method thereof. The herbicide for the potato field comprises the following componentsin percentage by weight: 1.3%-1.7% of rimsulfuron, 4.5%-5.5% of quizalofop-p-ethyl, 18.3%-20.7% of metribuzin, 10%-12% of an emulsifier, 3%-5% of a penetrating agent, 2%-3% of a stabilizer, and 4%-6%of modified organic bentonite, with the balance being an oil-based solvent. The modified organic bentonite is prepared by the following steps: mixing sodium bentonite with water, diethanol amine andpolyvinylpyrrolidone to obtain a sodium bentonite suspension, modifying the sodium bentonite suspension with a surfactant, and treating the modified sodium bentonite suspension to obtain the modifiedorganic bentonite. The herbicide provided by the invention has a very good control effect on gramineous weeds and broadleaf weeds in the potato field, is a dispersible oil suspending agent, and is safe and environment-friendly i