The Research On Environment Variation Characteristics Of Solar Greenhouses’ Soil Backwall In Ningxia Yinchuan

Because of the importance of backwall in the solar greenhouse,we study the thermal environment of the greenhouse soil wall of yinchuan ningxia, and the impact on the greenhouse environment and crop during the wall environmental changed, this test based on the observation, measurement and analysis of Ningxia Yinchuan greenhouse zone’s temperature, heat flux, the solar radiation changes of solar greenhouse wall of different vertical height; At the same time, we put different materials and different color besmear to brush paint on the back wall of greenhouse, to study the indoor environmental impact and the influence of the growth of crop. The results show that:(1) Solar greenhouse soil trapezoidal wall and ground solar radiation measurement analysis:solar greenhouse backwall daily solar radiation intensity of illumination from top to bottom in turn increases, sunny day3points, total radiation accounted for21.6%,36.6%and41.8%; Cloudy this proportion is22.5%,34.0%and43.5%; The solar radiation intensity of illumination southern is greater than the north, sunny take up62.0%and38.0%of the total amount of radiation; Cloudy ratio is63.2%and36.8%; In general, the ground total solar radiation is always higher than the back wall.(2) The surface sun radiation of the solar greenhouse wall from the top down in turn increases:2.21MJ/m2,2.30MJ/m’,3.O8MJ/m2; Whatever sunny or cloudy, the change of the temperature within the wall and the body sun radiation of the wall are same, means top is little11.13℃, middle12.62℃, low is hightest13.34℃; On the wall, and three parts heat from the top down in turn increases:85.60MJ/m2、85.80MJ/m2、92.89MJ/m2, and losed heat top is little76.47MJ/m2,middle is hightest96.88MJ/m2, low is middle93.70MJ/m2; Based on the determination of greenhouse backwall thermal environment, it can be found that the wall storage heat is directly related to the solar radiation, and wall suction exothermic and wall temperature, therefore, solar radiation directly influence the wall thermal environment.(3) Greenhouse backwall hang up different materials:hang up reflective screen have add lustre to effect, the average increase of light is11%-12%; Hang up the black film have constructive effect, average increase temperature1-5℃; But at the same time, the reflective screen’s ability of heat storage is reduced, make the night wall temperature reduce2-3℃, similarly, black film at the same time, the region will weaken the light around2%.(4) Greenhouse backwall hang up different materials has the influences on indoor plants:through the determination of all growth index and fruit quality of milk melon, hang up black membrane area and reflective screen area plant growth are better than blank bare wall.(5) Greenhouse backwall besmear different colors has a significant influence on the surface temperature and humidity:Temperature:black backwall significantly higher than blank bare wall19.3%than white backwall45.6%; Humidity:black backwall significantly higher than blank bare wall3.8%than white backwall7.9%; No matter sunny or cloudy, white backwall of indoor illumination distribution has significantly influence:the horizontal:white backwall significantly higher than blank bare wall2.9%than black wall11.8%, the vertical:white backwall significantly higher than blank bare wall0.4%than black wall0.5%. In a word, black backwall has warming humidification effects, white backwall has add light effect.(6) Different color backwall has influence on indoor plants’ growth:in cherry tomato’s rate of growth, the index measurement shows that black backwall plant growth better, but no significant difference between the others; White backwall area plant weight than black backwall0.46%, than blank bare wall5.63%, The longitudinal diameter and transverse diameter:black backwall area fruit higher than white backwall (2.45%,1.40%) and blank bare wall (3.52%,1.47%); In the greenhouse backwall besmear black, white painting, improve the cherry tomato fruit soluble solids content, total sugar content, acid content and vitamin C content, especially in total sugar, soluble solid content and total output; The different color backwall of greenhouse has influences on the plant photosynthesis, but not significant.From this test,we can know more about thermal environment of the greenhouse soil wall, hang up reflective screen and white painting can improve the light of greenhouse in the cloud day, hang up black membrane and black painting can improve the temperature in winter,at the same time,it also be good for plants’ growth.