Articles
RESPONSE OF SANSEVIERIA TRIFASCIATA VAR. LAURENTII TO SOIL TEMPERATURE MODIFICATIONS BY MEANS OF WASTE HEAT
Laurentii resulting from modifications of soil and air temperature obtained by heating with low enthalpy water (T=21–25°C), were evaluated in a double layer-air inflated polyethylene tunnel.
The temperature levels correspond to the thermal characteristics of waste waters from closed cycle wet tower thermoelectric power plants of ENEL (Italian Board of Electricity Production).
The modifications were also analysed in relation to four circulation patterns of waste water by means of pipes buried at two depths (10 and 20 cm) and at two horizontal distances (24 and 48 cm). A water-to-air heat exchanger was used for air heating.
As a control two similar polyethylene tunnels were heated by a warm air generator at a minimum threshold air temperature of 7°C and 15°C, respectively.
The increase in soil temperature resulting from waste water circulation through buried pipes was more significant in cooler months, and the thermal level was always higher in the soil heated by pipes nearer the surface and less distant from each other.
The rise in soil temperature caused earlier plant rooting, quicker blooming and increased ornamental quality of new shoots in Sanservieria trifasciata.
So this crop is to be considered very interesting for growing in soil heated by means of low temperature waste water.