suitable steaming method, certain factors have to be considered such as soil structure, plant culture and area performance. At present, more advanced methods are being developed, such as sandwich steaming or partially integrated sandwich steaming in order to minimize energy consumption and associated costs as much as possible. Deep soil steaming Deep soil steaming is a concept adopted by the Norwegian company Soil Steam international AS. They have developed a technology that gets the steam down to 30 cm deep in the soil. This is done in a continuous process and their last prototype managed to treat 1 hectare in 20 hours. When steaming the soil this deep, they get deep enough to prevent fall plowing from bringing up new seeds, fungi or nematodes. This means that the soil stays free from weeds, seeds, fungi and nematodes for many years after one deep soil steam operation. Sheet steaming Surface steaming with special sheets (sheet steaming) is a method which has been established for decades in order to steam large areas reaching from 15 to 400 m2 in one step. If properly applied, sheet steaming is simple and highly economic. The usage of heat resistant, non-decomposing insulation fleece saves up to 50% energy, reduces the steaming time significantly and improves penetration. Single working step areas up to 400 m2 can be steamed in 4–5 hours down to 25–30 cm depth / 90 °C. The usage of heat resistant and non-decomposing synthetic insulation fleece, 5 mm thick, 500 gr / m2, can reduce steaming time by about 30%. Through a steam injector or a perforated pipe, steam is injected underneath the sheet after it has been laid out and weighted with sand sacks. The area performance in one working step depends on the capacity of the steam generator (e.g. steam boiler): The steaming time depends on soil structure as well as outside temperature and amounts to 1–1.5 hours per 10 cm steaming depth. Hereby the soil reaches a temperature of about 85 °C. Milling for soil loosening is not recommended since soil structure may become too fine which reduces its penetrability for steam. The usage of spading machines is ideal for soil loosening. The best results can be achieved if the soil is cloddy at greater depth and granulated at lesser depth. In practice, working with at least two sheets simultaneously has proven to be highly effective. While one sheet is used