A high efficacy steam soil disinfestation system, Part II: Design and testing

The adoption of ecological solutions to eradicate soil-borne pathogens and weed seeds in horticulture is needed to protect both the environment and consumer safety. For these reasons, soil steaming, which was practiced in the past but has since been substituted by cheaper chemical treatments, is now being considered again. The lack of mechanisation of this technique and the high fuel consumption persuaded farmers to reject this disinfestation method. This paper presents the design, development and testing of a non-conventional steam application system for soil disinfestation, based on the coupling of an iron hood and a set of injectors. The device has been assembled on a caterpillar machine, equipped with a steam generator and an automatic guidance system, and tested in the open field. The equipment design followed extensive laboratory experimentation, reported in the companion paper (Gay, Piccarolo, Ricauda Aimonino, & Tortia, 2010), during which the effect of soil parameters on heat efficiency was assessed for different steam supply devices.