It is better to go beyond the frozen layer. The basic design of the greenhouse is based on the geological structure and local climatic conditions. The foundation is relatively deep in cold areas and loose soil areas. The greenhouse that cannot be produced throughout the year is deeper than the greenhouse that is produced throughout the year. The foundation filled with rubble or river stone should be filled with a 2030 cm thick ground beam. The insulation interlayer is filled with insulation materials such as benzene board and perlite. It is recommended to leave expansion joints if the wall exceeds 70 meters, and the rear wall of the greenhouse should be provided with certain ventilation windows according to the nature of the greenhouse for winter ventilation. Before the roof of the rainbow greenhouse wall is built and sealed, the arch embedded parts shall be installed for the installation of the arch. The height of the greenhouse wall is determined according to the span of the greenhouse. Generally, the height of the back wall of the 8m span greenhouse is 2.5m. The height of the back wall of the 7.5-meter span greenhouse is 2.3 meters. The site selection should be as flat as possible. The site selection of the greenhouse is very important. The groundwater level should not be too high, avoid high mountains and buildings that block light, and for planting and breeding users, sheds cannot be built in polluted places. In addition, areas with strong monsoons should consider the wind resistance of the selected greenhouse. The wind resistance of general greenhouses should be above level 8. The orientation of the greenhouse has a great influence on the heat storage capacity in the greenhouse, as far as the solar greenhouse is concerned. According to experience, it is better for greenhouses in the south to face westward. The west angle is 510 degrees. This facilitates the greenhouse to accumulate more heat. If multiple greenhouses are built, the spacing between the greenhouses should not be less than the width of one greenhouse. The orientation of the greenhouse means that the heads of the greenhouse are on the north and south sides respectively. For greenhouses engaged in planting, it is recommended to choose the north-south orientation. This orientation enables the crops in the greenhouse to be distributed evenly. The wall material of the greenhouse can be used as long as it has good heat preservation and heat storage capacity. The inner wall of the greenhouse emphasized here must have heat storage function, and the masonry of the solar greenhouse must be adapted to local conditions. In order to store heat. At night, this heat will be released to maintain the temperature balance in the shed. Brick walls, cement plaster walls, and earth walls all have heat storage capacity. It is generally better to adopt brick-concrete structure for the walls of greenhouses. The formation of toxic gases in the greenhouse and preventive measures. When cultivating vegetables in plastic greenhouses, the methods of fertilization are often improper, and ventilation is ignored, which causes excessive toxic gases in the greenhouses, which harms the vegetables, and is often misdiagnosed as diseases, resulting in failure to achieve the final results.
1. Nitrogen is due to excessive application of quick-acting chemical fertilizers such as urea and ermium sulfate, or improper fertilization methods. If the application of unripe organic fertilizers decomposes to produce ammonia under high temperature conditions in the shed, it will harm vegetables and cause leaf edge tissue to appear. Water-stain-like spots, when severe, the whole leaves die. It is often misdiagnosed as frost-old disease or other diseases. Vegetables that are sensitive to ammonia include cucumbers, tomatoes, and zucchini.
2. Nitrite gas Too much ammonium nitrogen fertilizer at one time will reduce the effect of certain bacteria and cause the soil to be acidic. When the PH value is less than 5, nitrous acid gas is produced, which can cause white spots on vegetable leaves, and severely whole leaves become white and dead. It is often misdiagnosed as powdery mildew. Vegetables that are sensitive to nitrous gas include eggplant, cucumber, zucchini, and celery. , Pepper, etc.
3. Ethylene and Chlorine If the quality of the agricultural film or mulch is poor, or there is residual mulch in the ground, expose it to the sun. Under the high temperature conditions in the shed, it is easy to volatilize and produce harmful gases such as ethylene and chlorine. When the concentration reaches a certain level, the vegetable leaf margins or veins can turn yellow, and then turn white. In severe cases, the whole plant will die. It is often misdiagnosed as bacterial keratoderma, which is particularly harmful to cucumbers. In addition, heating in winter is heating up, if the fuel is not burned sufficiently, toxic gases will be produced, and if the ventilation is not timely, too much carbon dioxide will accumulate. Affect vegetable production.
Precaution:
1. Fertilize reasonably. The organic fertilizer used in the greenhouse must be fermented and decomposed, the chemical fertilizer must be high-quality, and the urea should be mixed with the superphosphate calcium. The base fertilizer should be applied at a depth of 20 cm, and the topdressing fertilizer should be applied at a depth of about 12 cm. Water in time after application.
2. Ventilation. In sunny and warm weather, ventilation and ventilation should be combined with temperature adjustment, and ventilation and ventilation should be properly conducted in rainy and snowy weather.
3. Choose safe and non-toxic agricultural film and mulch film, and timely remove waste plastic products and their residues in the shed. For more relevant information, you can consult Chongqing Qingcheng Agricultural Technology Co., Ltd. Thank you!
