A MODEL OF COUPLED WATER, HEAT AND SOLUTE TRANSPORT FOR MULCHED SOIL BED SYSTEMS

Plastic-mulch culture is used extensively in Florida flatwoods and thr oughout the Coastal Plain of the southeastern United States for intens ive vegetable and fruit production, Elevated temperatures are often ob served in these mulched beds, which result in a different moisture flo w regime compared to unbedded systems (flat bare soil), A numerical mo del capable of effective description of the coupled processes of heat, water and chemical transport in these soil beds is presented, Applica tion of the model to cases of shallow and deep water tables(WT) of 30- and 120-cm, respectively, confirmed that high temperatures exist unde r plastic-mulched soil beds. With a MTT at the 30 cm depth the soil un der plastic mulch was relatively wet compared to the unmulched surface . Preliminary simulations demonstrate the potential for utilizing this model to investigate selected management practices for crops grown in mulched soil-bed systems.