New experimental results on a black body based soil solarization system

Soil solarization is a well-known agronomical practice used to eliminate the most part of pathogens accumulated during any crop cycle. This natural soil treatment exploits the solar radiation by heating it up to critical temperatures for weed, seeds and pests. A good solarization is able to increase the soil temperatures, at different depths, to destroy the negative pathogens, but it requires a long time (40-50 days) and its performance depends also on the thermo-optical properties of the plastic film used for covering the soil. The use of inadequate plastic film could frustrate a good soil sterilization, because the temperatures average levels during the whole period are too low to eliminate very harmful pathogens, like nematodes. Recently, we introduced an improvement of the traditional solarization, which is a black body based soil solarization system (B3S3), in order to exploit furtherly the solar heat with the increasing of temperatures in the soil and, as a consequence, to reduce the practice times (20-30 days). This new “integrated system” is similar to a thermal solar panel, used to produce hot water. It is constituted of two main elements: a very thin biodegradable black film which works as solar collector and of a thermal plastic film able to transmit almost totally the incident solar radiation (0.2-2.5 μm) and to block the main part of heat radiation emitted from soil. We report the experimental results of trials that confirm the huge potential of B3S3 as a concrete alternative to the fumigation system. The challenge is to introduce in agriculture our innovative solarization method that is at least as efficient as fumigation but harmless, highly efficient, biodegradable, easy to use and very cheap.