UTILIZATION OF LOW-TEMPERATURE GEOTHERMAL WATERS HEAT FOR PROTECTED CROP PRODUCTION

Abstract

Relatively abundant resources of low-temperature geothermal
and mining waters, which can be found in Poland, represent
a large potential for direct application for heating purposes
e.g. in horticulture. A number of studies were carried out on
the utilization of heat from geothermal waters for intensive
vegetable cultivation in foil tunnels in Banska Nizna, near
Zakopane, Poland. Heating system in the foil tunnels was
placed in the substrate and was the final element of a cascade
utilization of geothermal waters' energy. The temperature
of water used for heating was 35 - 45 0C. It allowed
extending the vegetation period and expedited the growth and
yield of the cultivated vegetables. Two soil heating options
were investigated in the experiment: standard and a closer
spacing heating grid. Based on the obtained results it was
stated that a closer spacing of the heating grid facilitates yielding
of fore- and after- crop vegetables. In the case of main
crop, higher yield was typical for vegetables cultivated on substrate
with standard spacing heating grid.