Transport of a degradable substance and its metabolites under drip irrigation

A two-dimensional model of water flow and transport of noninteractive solute in soils under drip irrigation, is extended to incorporate degradation pathway of a degradable parent substance and its metabolites. Adsorption of the parent material and its products to soil is also considered. The model yields two-dimensional distributions of water content and of the substance and each of its metabolites, and has a potential to be used for selected degradable substances, soil properties and management alternatives of practical interest to farmers and environmentalists. A sample calculation was accomplished for a single infiltration-redistribution cycle, with a parent substance applied in water as a line source during infiltration into a particular soil with a given set of hydraulic properties and coefficient of adsorption and degradation.