This invention discloses a cationic herbicide with reduced soil
passivation, using a cationic
polymer solution as the
solvent and the cationic herbicide as the solute. This invention combines the cationic
polymer with the cationic herbicide, utilizing the cationic
polymer to competitively bind to the soil, reducing the soil's adsorption of the cationic herbicide, thus slowing down the rate of soil
passivation of the cationic herbicide. The cationic herbicide with reduced soil
passivation effectively enhances the
efficacy and duration of
bipyridine herbicides, providing long-term control of weeds in the soil, thereby improving
weed control efficiency. It can be used for soil-applied herbicides for
weed control. When used in conjunction with a cationic herbicide-resistant direct-seeded
rice crop, it allows for
weed control while ensuring normal
rice growth, and the herbicide can remain on the weed emergence site for a period of one to two weeks, meeting the requirements for
weed control in direct-seeded rice fields.