Abstract: | The main processes which affect herbicide action in soil are considered to be the extent to which the herbicide is adsorbed by soil particles, the rate of absorption of the herbicide solution by plant roots and the rate at which the herbicide is lost from the soil by decomposition, evaporation or leaching. An attempt is made to show how these factors are interrelated and the possible use of mathematical models to optimise the performance of herbicides is briefly discussed. |