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.
