Archive for the ‘Soil Sterilization’ Category

The thermal sterilization of soil

Montag, August 10th, 2009

Heat has been used to control pests and weeds since the very beginning of agriculture.

Until today fields are burned down in order to create and improve soil fertility. Ancient civilizations such as the Indians or the Egyptians also systematically used sun radiation on irrigated agricultural soil to disinfect and revive arable land.

At the end of the 19th century the application of heat for soil sterilization is documented whereas two methods were developed simultaneously: the roasting of agricultural soil over an open fire and the steaming of soil with water vapor.

At the beginning steam was induced into the soil through drainage pipes. Later steaming hoods and harrows were used. The development of heat resistant sheets made the treatment of large areas with steam easy to handle.

The usage of dry heat (Roasting) for soil sterilization

Montag, August 10th, 2009

Even by burning down arable land, heat reaches down to up to 10 cm depth. In early times this method was used for intensive farming, in particular on plantations to cure root diseases and control weeds. At the beginning of the last century soil roasters were used in which substrate was filled and heated over open fire.

Today hot air devices are used for dry soil heating.

With dry soils the roasting method can lead to heat damages and destroy the organic components of the soil, which are essential for the growth of the plant. Therefore one has to pay attention that the soil is sufficiently humid and treatment does not last too long when using dry heat.