Soil solarization is a hydrothermal process that utilizes the sun's energy to heat moist soil that is mulched under polyethylene. The basic concept of soil solarization is to use clear plastic films to allow transmission of light energy to the soil, where it is absorbed and used to heat the soil. The clear plastic film decreases convective heat loss so that increased soil temperatures are achieved. If the temperature under the plastic film and in the soil reaches sufficiently high temperatures, weeds and other plant pests are damaged or killed. Consequently, the need for chemical pesticides, or the amount of pesticide, is decreased by using soil solarization. Accordingly, in arid cloud-free regions, the soil solarization technique has found wide application for the control of some soil-borne diseases and weeds.
Thus, in high light, cloud-free climates soil solarization with clear polyethylene films has been used successfully. However, in more humid environments, where clouds are a common occurrence, soil solarization is of less value in not providing the desired temperature. Further, one of the large losses of energy from the soil during solariation is as thermal-infrared radiation from the soil back through the film.
Thus, under a consistent cloudy environment, prior art soil solarization methods are less efficacious, particularly against certain noxious weeds, such as yellow and purple nutsedge (Cyperus spp). There is, therefore, a need for an improved method of weed control involving a more efficacious solarization technique and/or plastics film of use therein.