Fig. 6. 8. Energy balance of inside air.
In mulching it is assumed that the air between the cover and the soil surface is saturated
with water vapor and that its temperature is the arithmetic average of soil and cover surface
temperatures. In the present model, the air temperature between these two surfaces is one
of the unknown variables and must be defined in an integration form. The heat balance of
inside air is rather easy to calculate because of the lack of thermal radiation terms. Energy
comes through either cover, soil, or ventilation (see Fig. 6.8). Latent heat transfer also
occurs on the soil surface and is caused by ventilation.
, and the computed result is given in Fig. 6.10.