THE STUDY OF RELATED ENGINEERING TO HEAT PLASTC GREENHOUSE BY GEOTHERMAL ENERGY FOR RAISING GRAFTING FLOWER AND ERUIT TREE SEEDLINGS

This is a study on heating the greenhouses used for raising the grafting flower or fruit tree seedlings with geothermal energy . According to three years experiment it showed that the better way is to use the plastic arc greenhouse with zinc-plated steel tube skeleton structure. The seedbed is better to use the fine sand as the cultural material and pave the zinc-plated steel tube underneath in order to supply heat by geothermal hot water . The simple and easy electronic thermostat which was designed and made by authors was used to control the temperature of the seedbed . The stepped or stepless humidistat was used to control the relative humidity in the greenhouse . Authors also designed a complete set of grafting and culturing technological regulations for raising the flower or fruit tree seedlings. In such way, the soil temperature 5-10 cm under the surface of the seedbed kept at 25±3℃. and the relative humidity in the greenhouse at 85%. Under this environmental condition it shortened one third of the fruit tree seedlings forming stage and promoted the root growing rate up to more than 90% of above seedlings. By such cultural technology it breaks the limitaion of raising grafting flower of fruit tree seedlings in any season or region, It is also to get rid of the disturbing from the climatic variations, It can raise above seedlings mere effectively and get remarkable economic benefits.