Research On The Application Effect Of Two New Types Of Material Back Wall Solar Greenhouses In Yangling

In order to explore the application effect of different back wall materials of greenhouse in winter,two new wall materials were used in this experiment,namely the No.2 light aggregate concrete block back wall solar greenhouse（W₂）and the No.3 cement pipe sand column back wall solar greenhouse（W₃）,compare these two kinds of greenhouses with No.1 ordinary clay brick wall solar greenhouse（W₁）,environmental indicators such as indoor temperature,back wall temperature,heat storage of the back wall,and growth indexes of indoor cultivated tomato crops were analyzed.Comprehensive consideration of construction cost,the main results are as follows:（1）In terms of indoor environment,W₃ is 1.4 and 2.2℃higher than W₂ and W₁ on sunny days;daily average ground temperature is 0.8,1.2℃higher;daily average humidity is3.0%,3.9%lower;wall heat output at night is 0.14,0.25 MJ/m² higher.Both showed the best effect of W₃.On cloudy days,W₂ is 2.3 and 3.8℃higher than W₃ and W₁ at night;daily average ground temperature is 0.7 and 1.3℃higher;daily average humidity is 1.7%higher and 1.9%lower;wall heat output at night is 0.05,0.11 MJ/m² higher.Except for humidity,W₂ works best.（2）In terms of wall temperature and heat storage and release,the temperatures of W₁,W₂,and W₃ walls at various depths in sunny days are all expressed as W₁<W₂<W₃.The temperature of W₃ walls is always the highest at different depths,indicating that in sunny weather,its heat storage capacity is strong;while the temperature of W₁,W₂,and W₃ walls in cloudy days is expressed as W₁<W₃<W₂,and the temperature of W₂ walls is the highest,showing that it has a good insulation effect in cloudy days.Wall temperature reflects the heat storage and release.W₃ absorbs the most heat during the day on a sunny day and releases the most heat at night.In cloudy weather,although the wall of W₂ absorbs less heat during the day than W₃,it releases the highest heat at night and releases it on the same day.The heat is almost close to the heat absorbed.（3）Through the numerical simulation of 3 test greenhouses,the distribution pattern of the temperature field of the greenhouse and the wall was obtained,and the above-mentioned measured values and related conclusions were verified.（4）From the perspective of greenhouse application effects,the plant height and stem thickness in the middle and late stages of tomato growth and development are all W₃>W₂>W₁;flowering time W₃ is 3 days earlier than W₂ and 6 days earlier than W₁;single fruit weight W₃ is 16.28g more than W₂,30.18g more than W₁,single plant yield W₃ is0.14kg more than W₂,and 0.25kg more than W₁.Compared with the W₁ ordinary clay brick wall sunlight greenhouse,the greenhouse cost W₂ and W₃ increased by 15.6 yuan/m² and decreased by 30.9 yuan/m².（5）Therefore,through the overall evaluation,this study believes that W₃,the cement tube sand pillar rear wall,has high indoor temperature,high fruit yield,low cost per unit area,convenient construction.So it is most suitable for winter application in Yangling area.