The effect of reirrigation on the thermal regime of polyethylene-mulched soils: Experimental and numerical studies

Soil solarization is used to control soil-borne pests in regions with high temperatures and intense solar radiation. The method mulches wet, bare soil with transparent polyethylene sheets. Reirrigation during mulching is occasionally practiced to keep the soil moist. Sometimes this achieves higher killing rates, but at other times it has no effect. A one-dimensional numerical model was applied to study the effect of reirrigation on the temperature regime of several mulched soils. Field measurements were carried out in a sandy soil to verify the model predictions. Model results agree well with the observed data. Reirrigation may either increase or decrease maximum mulched soil temperatures, depending on soil thermal and hydraulic properties. When reirrigation is needed, the most appropriate time is generally during the late-night hours. This model may be used to decide whether reirrigation is needed.