Movement of fluometuron and 36Cl− in soil under field conditions: computer simulations

Summary The movement of chloride ion and the movement and degradation of fluometuron in two soils of contrasting texture and structure was predicted with a simulation model which included terms for the degradation of fluometuron as a function of temperature and moisture. The simulated distributions of soil water, chloride ion and fluometuron were compared with the observations reported in a previous paper (Hance, Embling, Hill, Graham‐Boyce & Nicholls, 1981), Soil waler contents and fluometuron distribution were simulated reasonably accurately. Movement of chloride to below 30 cm in both soils and degradation of fluometuron in the WRO sandy loam soil were not well simulated. The discrepancies between observed and predicted water contents and chloride distribution show the importance of measuring dynamic as well as static water properties. Therefore refined simulation models may need to account for pore continuity, soil particle movement and mobile and immobile categories of water.