Cactus winter temperature management

The management of temperature conditions is an important part of the management of protected areas. Edible cactus habits are warm and the cold resistance is weak. If it cannot create good and suitable temperature conditions, its growth and development will be affected. Therefore, it is very important to eat cactus temperature management.

1. Heat preservation and temperature increase measures for plastic greenhouses

1 Use high-quality film to increase geothermal storage by increasing the amount of light entering the shed. High-quality films are resistant to low temperatures and aging.

2 Dig out the cold-proof ditch around the greenhouse. The depth is based on the local permafrost. The width is 50-70 cm. It is filled with horse dung, sawdust or straw, straw, etc. The top cover is solid and slightly higher than the ground.

3 Multi-layer covering, except the cover film, in the 20-30 cm from the film under the greenhouse film horizontal pull a few roads, wire hanging film or non-woven fabric, open during the day, close at night, to form a two-layer film, can be Increase the minimum shelf temperature by 2°C. In addition, small sheds can be used in the sheds, straw drapes and quilts can be covered at night outside the shed. These methods have good practical effects in the northern regions where light is good, early spring temperature is low, temperature difference between day and night is large, and temperature is variable.

4 In the greenhouse, small arches are added on both sides. The temperature distribution inside the plastic greenhouse is uneven. The upper part of the day has high temperature and the lower part has lower temperature; the lower part of the night has high temperature and the upper part has low temperature; the middle part has high temperature and the two sides have low temperature. As a result, cactus often grows in the middle and is small on both sides. The solution to this problem is to set up small sheds on both sides of the greenhouse to promote the simultaneous and uniform growth of cacti in the shed.

In addition to the warming of insulation, the management of temperature conditions also includes cooling. The main use of ventilation cooling. When the temperature in the greenhouse rises to the appropriate limit (35°C) for the edible cactus, timely ventilation and cooling are required to open the door, and aprons on both sides of the greenhouse can also be lifted to carry out the bottom wind on both sides. When it is fine (mainly at noon), gradually increase the ventilation area and extend the ventilation time as the outside temperature increases. Take the responsibility of a person in charge, and implementing the “early opening the door at night to close the door” management method with weather changes can effectively prolong the growth time of the cactus and increase the yield.

2. Warming and heat preservation measures in sunlight greenhouse

1 Wall: The back wall and the gable are the main parts of the cold wind. In order to make full use of the thermal insulation effect of heat storage and heat insulation, most areas currently use earth-based or rubble walls, and cultivate the cold soil behind the walls. In cold regions, the thickness of the wall can reach more than 1 meter. For example, brick walls are used to promote the use of hollow walls and heat-insulating materials to enhance the heat preservation effect; wind barriers can also be installed outside the walls and straws can be filled between walls and wind barriers.

2 The rear roof: The rear roof is also a key part of the cold wind. In order to improve its heat storage and heat preservation performance, two measures can be taken: First, the elevation angle of the roof after the construction of the greenhouse should be appropriate, generally 30 degrees to 40 degrees; First, the cover material of the rear roof should be light, strong, leak-proof and well-insulated material, and the multi-layer composite structure is preferred. For example, in the northeast China, the first layer is made of corn stalks and sorghum straw mats on the linden wood, and the second layer is mulled with two layers of grass mud, with a layer of plastic film sandwiched between them and integrated with the back beam to prevent ventilation. The third layer is a stack of 30-40 cm thick straw; the fourth layer is a whole bundle of corn stalks or straw.

3 Front roof: The front roof is the lighting part of the greenhouse and is also the main heat sink at night. Therefore, it is extremely important to cover it with straw or paper. Grass straws are mostly made of rice straw or rice dumplings, and paper sheets are made from multi-layered kraft paper. The paper is generally covered in straw curtains. The straw curtains can be single-layered or double-layered. In addition, the setting of a thermal screen or a small shed in a greenhouse can increase the room temperature by 2-3°C. If used simultaneously, the effect is better.

4 Cold-proof ditch: The cold-proof ditch has a certain effect on the warm-keeping of the greenhouse. The method is to prevent the cold in the surrounding of the greenhouse, especially in the front-end digging depth and the same depth of the frozen layer, a width of 50-70 cm in the ditch, filled with straw, straw, etc. The object is covered with soil, and the mound is slightly better on the ground.

5 The establishment of a greenhouse at the door of the greenhouse and the hanging of double curtains also contribute to the greenhouse insulation. Like the plastic greenhouses, while actively doing a good job of insulation and cold work, it is also necessary to pay attention to the problem of greenhouse cooling. At noon on a sunny day, when the temperature of the greenhouse gas rises above the optimum temperature for the development of the cactus, the temperature is lowered. The most common cooling method is ventilation.

In addition, whether it is a plastic greenhouse or solar greenhouse, temperature management also needs to pay attention to the following points:

1 According to the change of temperature, the film should be covered as early as autumn to ensure that the ground temperature does not decrease with the temperature. If the spring temperature does not stabilize above the suitable growth temperature of the cactus, do not rush to open the greenhouse prematurely. It should be gradually released according to the characteristics of climate change to prevent a sudden drop in temperature and affect the growth of the cactus.

2 It is necessary to arrange for someone to be responsible for the uncovering of the straw curtain every day. It should not be too early to uncover the grass curtains, nor should it be too late. It should be based on the temperature and light conditions. It was too early to be revealed in the morning and the late evening had an effect on the temperature; it was too late for the morning to be exposed, and too early to be covered in the afternoon would affect the light. In case of a cloudy day when the temperature is too low, the straw curtain may not be lifted.

3 After snowfall, the snow on the shed should be cleaned in time to prevent collapse of the greenhouse.

3, heating greenhouse heating measures

1 Structure The structure of the heating greenhouse is basically the same as that of the solar greenhouse. This kind of greenhouse is better than the first light, it must be able to make full use of the thermal energy of the sun, and has a very good thermal insulation facilities. On this basis, install additional heating facilities. At present, heating measures mainly include flue heating and heating, and heating facilities are generally heated at the back wall of the greenhouse or at the front of the back wall and greenhouse.

(1) Flue heat. This is a relatively simple heating facility. The construction is simple, the cost is low, and the utilization of heat energy is low, generally 25-30%, which is suitable for use in a simple small greenhouse. There are three parts: the stove, the flue, and the chimney. The heat released by the combustion of coal is dissipated through the flue of the stove to increase the temperature of the greenhouse. Flue heating should be strengthened to prevent smoke.

(2) Heating with water. The plumbing heating system consists mainly of ducts, radiators and boilers. When warming, the water in the boiler is heated with fuel, and the hot water passes through the pipeline and enters a radiator such as an iron pipe or a radiator in the greenhouse. After the hot water is cooled, it is returned to the boiler, reheated, and then enters the circulation. This heating method is mainly applied to large greenhouses or greenhouse groups. Hot water heating can not only heat the air temperature, but also can lay pipes at a certain depth underground, heating the ground temperature.

2 performance characteristics Temperature is easy to adjust, heat storage, heat preservation effect, strong ability to resist bad weather.

3 Appropriate areas are mainly suitable for use in cold winter regions such as northern North China, Inner Mongolia, and Northeast China.