SOIL TEMPERATURE IN GREENHOUSE SOIL SOLARIZATION USING TIF AND VIF AS MULCHING FILM

The aim of this paper was to evaluate the performance of Totally Impermeable Film (TIF) and Virtually Impermeable Film (VIF), generally used in fumigation, in increasing soil temperature during a greenhouse solarization treatment, in comparison with a commonly used LDPE film. Preliminarily, laboratory measurements of perpendicular spectral transmittance of these film were performed both in solar (200-2500 nm) and in infrared (2500-25000 nm) wavelength range. Subsequently, a field trial was carried out in Sicily in a multi-span tunnel greenhouse, with steel-made structure, sized 90 m × 24 m. Four treatments were performed on plots sized 3 × 24 m arranged in randomized complete block design (RCBD) with three replications. For each replica one plot was left un-mulched as control and three plots were mulched with LDPE, TIF and VIF film. The solarization treatment was performed from 17 July to 6 September 2015. During all the trial soil temperature was measured at 5, 15 and 30 cm depth. Furthermore, air temperature, air relative humidity and total radiation flux were measured outside and inside the greenhouse. The results show that both TIF and VIF film have better spectroradiometric properties than the LDPE film and that the soil temperature reached in the trial at 15 and 30 cm depth under TIF and VIF film were significantly higher than the ones obtained under LDPE.These results encourage to consider the joint use of a low-dosage fumigation followed by solarization in the control of soil pathogens in order to obtain a further reduction in the amount of fumigant used.