| As a major type of facility agriculture,solar greenhouse provides favorable conditions for annual crop production.However,in most parts of China,the temperature in the summer is becoming hot and hot,and the temperature in the greenhouse is often over 40℃.High temperature in solar greenhouse leads to high temperature stress on crop growth and development,and crop quality and yield have been greatly affected.In addition to the obvious cooling efficiency,atomization cooling technology is also an effective way to supplement the lack of plant moisture caused by transpiration in greenhouse cultivated crops and reduce the cooling mode of water stress.Therefore,this study independently develops a new cooling method of solar greenhouse,namely,a composite cooling system covered by atomized cooling+intermittent internal shading+paper film.The analysis of air temperature and humidity,light intensity,matrix temperature and humidity and matrix nutrient in typical high temperature weather was systematically analyzed,and the influence of composite cooling system on greenhouse space environment and matrix characteristics was investigated.Taking the JinFei and QianXi cherry tomatoes widely grown as the test material,through the growth of cherry tomatoes of different varieties,the regulation effect of cooling system on tomato growth and quality was explored,and the comprehensive regulation system of solar greenhouse production environment was established.It provides theoretical and technical support for the high quality growth of tomatoes in the north of China.The main research results are as follows:(1)The cooling system of solar greenhouse over the summer includes solar greenhouse(10),paper film(20),atomized cooling machine(30),and internal shading(40).In the solar greenhouse(10),(60)crops were planted on(50)surfaces,(20)covered with paper film on(50)surfaces,and the light transmittance of paper film(20)was 10%～13%.(2)The results of this experiment show that under the treatment of atomized cooling,intermittent internal shading and paper film covering three-dimensional composite cooling system,the average greenhouse cooling temperature is 2.13℃,and humidification is 5.47%.The air temperature in the greenhouse is below 35℃ and the substrate temperature is less than 30℃,which meets the demand for suitable growth temperature and humidity of tomatoes.(3)Compared with the control group,the composite cooling system improved the EC value of tomato matrix,and decreased the pH value,increased the total nutrient,decreased the available nutrients of JinFei cherry tomatoes,decreased the fast nitrogen,increased the fast phosphorus and the quick potassium,and increased the amount of and trace elements treated by JinFei cherry tomatoes except K and Cr.QianXi cherry tomatoes process a lot of elements,and trace elements in addition to Ba elements,add other elements.(4)The composite cooling system provides an appropriate growth environment for tomatoes growth,thus increasing the content of organic acids,vitamins C,soluble solid and soluble sugar in JinFei and QianXi tomatoes,respectively,with an increase of 14.36%,42.82%,11.84%,21.56%and34.05%,33.29%,14.06%,14.06%and 23.15%,respectively.(5)The composite cooling system effectively reduced the temperature of the canopy and root regions of tomatoes,and the net photosynthetic rate of JinFei and QianXi cherry tomatoes the treatment of the increased by 71.68%and 32.43%,respectively,and the transpiration rate decreased by 29.61%and 119.86%,respectively.The cooling system treated the yield of the JinFei and the QianXi cherry tomatoes per plant increased by 23.63%and 12.25%respectively. |
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