solar greenhouse and planting

The solar greenhouse is the abbreviation of the energy-saving solar greenhouse, also known as the greenhouse, which consists of two side gables, a wall after maintenance, a supporting frame and covering materials. It is a unique type of greenhouse in northern my country. It is a kind of greenhouse without heating indoors. The back wall absorbs solar energy to realize heat storage and release, and maintains a certain indoor temperature level to meet the needs of vegetable crop growth. (There are also some farmers who increase heating measures in the greenhouse, such as furnaces, boilers, heating pipes, or night heat preservation measures, such as roller blind quilts, etc.

The solar greenhouse adopts relatively simple facilities and makes full use of solar energy. In cold regions, vegetables are generally cultivated overwintering without heating. The solar greenhouse, which is a cultivation facility for fresh vegetables, has distinctive Chinese characteristics. It is a facility unique to our country. The structure of solar greenhouses varies from place to place, and there are many classification methods. According to the wall material, there are mainly dry soil greenhouses, masonry structure greenhouses, and composite structure greenhouses. According to the length of the rear roof, there are long back slope greenhouses and short back slope greenhouses; according to the form of the front roof, there are two-fold type, three-fold type, arched round type, micro-arched type, etc. According to the structure, there are bamboo-wood structure, steel-wood structure, reinforced concrete structure, all-steel structure, all-reinforced concrete structure, suspension cable structure, hot-dip galvanized steel pipe assembly structure.

The front slope is covered with thermal insulation at night, and the east, west, and north sides are single-slope plastic greenhouses with enclosure walls, collectively referred to as solar greenhouses. Its prototype is a single-slope glass greenhouse, and the light-transmitting covering material on the front slope is replaced by plastic film to replace glass, which evolved into an early solar greenhouse. The solar greenhouse is characterized by good heat preservation, low investment, and energy saving, which is very suitable for use in rural areas with underdeveloped economies in our country.

historical origin
The origin of the greenhouse can be traced back to the period of Qin Shihuang. According to the scholar Wei Hong's "Preface to the Ancient Civil Official Books", "Qin burned the books, fearing that the world would not change the law. The seven hundred people are densely planted melons in the middle of the Lishanling Valley." It is said that he lived for more than 200 years by burning books and burying Confucian scholars, and his records must have word-of-mouth history as the basis.
Yan Shigu, a scholar of the Tang Dynasty, said in the annotation of "Hanshu Volume Eighty-eight Confucian Biography Fifty-eighth" that "the wet soup place in Xinfeng County today is named Min Confucian Township." The "wet soup place" should be Wei Hong said that "the middle temperature of Lishan Mausoleum Valley" further consolidated Wei Hong's credibility. Wei Hong's records about Qin Shihuang revealed a piece of valuable agricultural technology information, that is, during the period of Qin Shihuang, the Chinese had invented greenhouse technology.

Although my country is the country with the earliest origin of greenhouse cultivation, by the 1960s, China's greenhouse industry was always in a small-scale, low-level, and slow-growing state. Certain role. With the development of the economy and the advancement of science and technology, plastic greenhouses and solar greenhouses appeared one after another in the 1970s and 1980s. Since the 1990s, China's facility agriculture has gradually developed in the direction of large-scale, intensive and scientific, and its technical level has been greatly improved.
With the launch of relevant national scientific research projects in recent years, on the basis of learning from and absorbing foreign advanced technological achievements, China's facility agriculture has developed rapidly, and the area and level of facilities have been continuously improved.
As the main body of my country's protected agriculture industry, the "sunlight greenhouse" industry has become the most profitable industry in agricultural planting in the past 20 years. It solves the long-term off-season supply of vegetables in winter in northern my country, increases farmers' income, saves energy, promotes the adjustment of agricultural industry structure, drives the development of related industries, arranges employment, avoids environmental pollution caused by the greenhouse effect, and improves the living standards of urban and rural residents. Historic contributions have been made to stabilizing society

Application of Greenhouse Technology——Smart Vegetable Garden
In the 1970s and 1980s, solar greenhouses appeared in China, and the Chinese greenhouse industry began to enter the fast lane. Afterwards, multi-span greenhouses, smart greenhouses, plant factories, low-carbon IoT greenhouses, and smart vegetable gardens continued to have new technological breakthroughs.
The smart vegetable garden can be described as the "essence" of modern greenhouse technology. When it comes to plant factories, many people have heard that Jingpeng Plant Factory, the first large-scale plant factory in China, was built and put into use as early as 2010. The smart vegetable garden we are talking about here is the home version of the plant factory application. The technology of the plant factory is very mature, and it is still difficult to apply it as a home user. The emergence of the smart vegetable garden has solved this problem, which just meets the potential needs of home gardening.
The second-generation product of the smart vegetable garden met with the audience at the Science and Technology Expo and the Technology Week. There were always some curious users around it, casting strange eyes on the vegetables in the smart vegetable garden, because it has no soil and no sunshine, those lettuce But it's growing very well. The smart vegetable garden is about the same size as today’s refrigerators. It can be placed in the kitchen and living room. It can grow a crop in about 30 days after mixing the nutrient solution. It can be planted repeatedly. Having a smart vegetable garden at home can provide long-term and stable supply of pollution-free, high-quality vegetables vegetable
The light transmittance of energy-saving solar greenhouses is generally above 60%~80%, and the temperature difference between indoor and outdoor can be kept above 21~25 degrees Celsius.
lighting
On the one hand, solar radiation is the most important source of energy to maintain the temperature of the solar greenhouse or to maintain heat balance; on the other hand, solar radiation is the only light source for photosynthesis of crops.
Sunlight is an indispensable energy source for green plants to carry out photosynthesis, and it is also the main heat source for solar greenhouses. Therefore, when designing a solar greenhouse, the lighting problem of the greenhouse must be solved first, so that the sunlight can be transmitted to the inside of the greenhouse to the maximum extent.
Solar greenhouses in northern China are mainly used in winter, spring and autumn. In winter, the solar altitude angle is low, the sunrise is in the southeast, and the sunset is in the southwest. Therefore, in order to maximize the use of sunlight in winter, solar greenhouses mostly adopt the orientation of facing south and extending from east to west.
Practice has proved that the outside temperature is very low in winter mornings, and the indoor temperature of the eastern greenhouse often drops significantly after the straw curtains are opened in the morning. The orientation of the solar greenhouse should be as far west as possible, which is conducive to prolonging the light time in the afternoon and keeping warm at night. It is advisable to take 5 degrees to the west and not exceed 10 degrees.
When the incident angle of light increases from 0 degrees to 40 degrees, it has little effect on the light transmittance of transparent materials, and the reflection loss rate of light quantity is only a few percentage points; when the incident angle changes from 40 degrees to 60 degrees, the light transmittance The light transmittance shows a significant downward trend with the increase of the incident angle; when the incident angle is greater than 60 degrees, the light transmittance shows a sharp downward trend. Therefore, the incident angle of 40 degrees or the projection angle of 50 degrees is the critical point that affects the light transmittance of transparent materials. In the initial stage of solar greenhouse development, the lighting angle at which the maximum projection angle of the sun on the lighting surface of the greenhouse on the winter solstice reaches 50 degrees is set as a reasonable lighting roof angle
The thermal insulation of the solar greenhouse consists of two parts: the thermal insulation enclosure structure and the movable thermal insulation quilt. The insulation material on the front slope should be made of flexible material so that it can be easily stowed after sunrise and put down at sunset.
The research and development of new front roof insulation materials mainly focus on the requirements of mechanized operation, low price, light weight, aging resistance, waterproof and other indicators.
The solar greenhouse is mainly composed of three parts: the enclosure wall, the rear roof and the front roof, referred to as the "three elements" of the solar greenhouse. The front roof is the entire lighting surface of the greenhouse, and the front roof is only covered with plastic film for lighting during the daylighting period. When the light weakens, cover the plastic film with the active heat preservation quilt in time to strengthen the heat preservation of the greenhouse.

Due to the development of the plastics industry and the fact that the glass is easily damaged, most of the solar greenhouses in rural areas use plastic film as the roofing material. In particular, the plastic solar greenhouse developed on the basis of soil greenhouses in northern my country has obvious characteristics of high efficiency, energy saving, and low cost. will develop faster. Practice has proved that where the minimum outdoor temperature is not lower than -25°C, using the special structural properties of the plastic solar greenhouse can keep the indoor temperature above 5°C, and satisfactory results can be obtained.
plant
1. Variety selection.
Select high-quality and high-yield varieties such as local cucumbers, Shanghai Yangxing cucumbers, and Nongda No. 14.
Second, cultivate strong seedlings.
The sowing period of cucumbers in greenhouses can be from late December to early and mid-January, and it is advisable to use greenhouses plus small arches (or electric heating hotbeds in greenhouses) to raise seedlings. The seedling age is 40-45 days, and the seeding rate is about 0.1 kg per mu. First soak the seeds in clean water, then put them into hot water at 55°C, the amount of water is 3-4 times that of the seeds, keep stirring, when the water temperature drops to about 30°C, then soak the seeds at room temperature for 1-2 hours stand-by. Select the plots that have not been planted with melon crops in recent years as seedbeds, level the bed soil, pour enough bottom water, and sow seeds 24 hours later. Sow 0.2 kilograms of seeds per square meter of bed surface, and cover with 2 centimeters of medicinal soil (50 kilograms of soil marl+1.5 kilograms of calcium magnesium phosphate fertilizer+0.15 kilograms of zinc zinc+0.15 kilograms of thiophanate).
From sowing to cotyledons unearthed, it is necessary to maintain a higher temperature. When the temperature reaches 15°C, put on the apron of the greenhouse; The specific temperature requirements are: keep around 25°C-30°C during the day and around 20°C at night. After the seedlings are unearthed, the temperature should be properly cooled, about 25°C during the day and about 16°C at night. 4-5 days after sowing, move the seedlings into the nutrient pot. After transplanting the seedlings to before the living trees, keep appropriate high temperature and high humidity, keep the seedbed at 25-30°C, and gradually cool down after 3-4 days. Control it at 20-25°C during the day and 14°C at night. -16°C to prevent leggy growth. During the seedling stage, the bed soil should always be kept moist, and watering should be carried out on sunny days. It can be combined with 0.2% potassium dihydrogen phosphate + 0.2% urea as top dressing, and the ventilation should be sufficient after application to promote strong seedlings.
3. Timely planting.
The greenhouse is covered with a small arched shed with plastic film and grass curtains for cultivation. From mid-February to early March, when the seedlings are 40-45 days old, the plant height is 15-20 cm, and there are 5-6 true leaves. Generally, two rows are planted in each plot, the row spacing between plants is 40-60cm, and 2500-2700 plants are planted per mu.
Fourth, strengthen field management.
1. Fertilizer and water management. Half a month before planting, ditch in the furrow and apply base fertilizer, 1500 kg of barn fertilizer per mu, 1000 kg of human excrement and 45 kg of compound fertilizer. After planting live trees, apply 1,000 kg of human excrement per mu, and topdress them again after 15 days. Cucumbers grow fast, and the supply of fertilizer and water should be timely. The fertilization method adopts the principles of "thin fertilizer and frequent application" and "small amount of frequent meals". Generally, topdressing is applied once every two harvests. Keep the soil moist throughout the growing season. After entering the melon filling period, water and irrigate once every 1-2 weeks according to the soil moisture content.
2. Temperature control. After planting, keep the shed temperature higher to facilitate seedling growth. After slowing down the seedlings, measures such as heat preservation, antifreeze and ventilation, and heat protection should be strengthened. Generally, on sunny days, ventilate when the temperature in the shed reaches 28-30°C during the day; on cloudy days, properly ventilate, keep the temperature at about 20°C, and keep the shed temperature at 15°C (not lower than 10°C) at night. Uncover early and late to increase light. Generally, the small arch shed is removed before the vines are set up, and the side film of the greenhouse is removed in late April, and the top film is kept until the end of harvesting.
3. Apply hormones to preserve flowers and fruits, and use Baoguoling 100 times liquid to spray flowers and fruits at the initial flowering stage to increase early yield.
Five, pest control.
The main diseases are downy mildew, blight, fusarium wilt and powdery mildew. It is necessary to implement agricultural measures such as water and dry crop rotation and spreading quicklime to prevent the occurrence of diseases. In particular, pay attention to the early prevention and treatment of downy mildew. Generally, cucumbers in greenhouses begin to occur in the middle and late March. When the temperature rises to 20-24°C after Qingming, it can spread rapidly. Therefore, starting in mid-March, spray with 25% carbendazim or 70% Antaisheng or 58% rutamine 500 times solution every 5-7 days; Dew 750 times liquid or 69% Anke 600 times liquid control. In cloudy and rainy weather, 0.2 kg/mu of 45% chlorothalonil fumigant can be used. Close the greenhouse for fumigation in the evening, ventilate the next morning, and use it in rotation with spraying. Pests are mainly aphids, which can be controlled by Comfort 7000 times or Yiyijing 2500 times.
Planting Technology of Cucumber in Greenhouse in Early Spring
Due to the large planting area and continuous cropping of cucumbers in early spring greenhouses in some old vegetable areas, cucumber wilt and epidemic diseases occurred frequently, posing a threat to the production of cucumbers in greenhouses. Through the comprehensive application of measures such as cucumber grafting and temporary heating of the fire, we have effectively solved the problem of soil-borne diseases [4] and improved the economic benefits of growing cucumbers.
1. Select cucumber varieties in protected areas
Shandong Mici, Xintai Mici, and Jinchun 3 are resistant to low and high temperatures, and are dense in melons. They are very suitable for greenhouse planting in early spring.
2. Grafting seedlings
The cucumber sowing time is in mid-January, the calendar seedling age is about 50 days, and the physiological seedling age is 5 or 6 leaves and 1 heart is better. The rootstock is black-seeded pumpkin, and the scion is sown 3 days earlier than the rootstock. Both the rootstock and the scion seeds need to be blanched before sowing. After germination, they are sown on wood with furnace ash and perlite or sawdust soaked in hot water and some nutrient soil. box or plastic tray. The grafting method is the belly-cut grafting method, and its biggest advantage is that the cucumber seedlings can be of any size. After grafting, a small shed will be buckled in the greenhouse and covered with grass thatch for shading management.
3. Ethephon treatment of seedlings and transplanting
When the cucumber grafted seedlings have 2 leaves and 1 heart, spray 150-200ppm ethephon in time, the purpose is to increase the number of female flowers, which is the key to good early yield of grafted seedlings. When the seedlings have 3 leaves and 1 heart, transplant the seedlings in time. You can make a cross or move them to a plastic nutrient bowl. Train the seedlings at low temperature before transplanting, after transplanting the seedlings at 27-29°C in the daytime, slow down the seedlings at 15-18°C at night, and then cool down for management. 7 days before planting, the night temperature gradually dropped to 7-8°C to train the seedlings.
4. Colonization time in early March
In order to make the ground temperature rise, the shed will not be watered before winter, and the shed will be baked 30 days in advance, and the land will be prepared for the border. Every 667 square meters will be applied with 4000-5000 kg of chicken manure, 50 kg of diammonium in the furrow, and 40 meters away from the top membrane. Pull the second-membrane support along the shed pillars centimeters, and hang the second-membrane in mid-February. When the soil temperature at a depth of 15 centimeters is stable at 12°C, plant the plants with a row spacing of 60 centimeters and a plant spacing of 33 centimeters, and keep 3,500 to 3,800 seedlings per 667 square meters. After planting, buckle the small arch shed according to the furrow shape, and cover it with three films of plastic film. At night, the earthen stove with the flue is lit in time and placed in the center of the shed, and the shed is surrounded and covered with grass thatch.
5. Greenhouse management
(1) Temperature management: Keep the temperature in the small shed at 28-32°C during the period of cucumber grafting and slowing down the seedlings. When it reaches 35°C during the day, remove the film of the small shed in time and cover it at night. 10 days after planting, remove the grafting clips and the small arch shed film. Open the second film appropriately at noon, keep the shed temperature above 28°C during the day, remove the second film when the lowest nighttime temperature is 5°C, and enter the routine management. (2) Water and fertilizer management: Generally, the root melon sits and pours the second water, and when it reaches the waist melon, the water and fertilizer are all attacked, and the dilute manure and chemical fertilizer are used alternately (manure—clear water—chemical fertilizer). 4 times about 3 to 4 parties, 100 kg of urea.
Common Problems in Greenhouse Cucumber Planting
1. Malformed melon
Including curved melon, sharp-billed melon, pot-bellied melon, bee-waisted melon and so on.
1. The reason for the appearance of curved melons is that during the seedling cultivation stage, the temperature and humidity are not suitable or the nutrient supply is insufficient, resulting in poor development of the ovary, which naturally develops into curved melons; when the cucumbers are fattened, improper field management can easily form curved melons. A better way to avoid the above situation is to create good environmental conditions for the differentiation of cucumber flower buds during the seedling cultivation period, and at the same time strengthen the management of fertilizer and water during the expansion period of melon strips.
2. Sharp-billed melon is caused by poor fertilization and continuous high temperature in the shed. Therefore, when the temperature in the greenhouse exceeds 30 degrees Celsius, timely ventilation is required to prevent the occurrence of high temperatures. After starting to sit melons, fertilizer and water management should be strengthened to keep the soil moist and cultivate strong plants.
3. Pot-bellied melon The first reason is poor fertilization, and the second is zinc deficiency in the soil. Therefore, it is necessary to select varieties with strong parthenocarpic properties as the main planting varieties in the greenhouse, and on this basis, apply zinc sulfate as the base fertilizer in combination with site preparation.
2. Flower topping phenomenon
The reason is that after planting the slow seedlings, the roots were not well promoted and the plants were controlled, and the topdressing and irrigation were too early. Due to the drop in ground temperature, the activity of the root system is weakened, and the nutrition cannot keep up, causing the flowers to top. In case of the above phenomenon, the melons should be harvested early, and part of the female flowers should be removed, watered and topdressed with nitrogen fertilizer in sunny days.
3. Yellow leaves
This is due to insufficient nutrient supply. Cucumber is a plant that requires a lot of fertilizer. Not only must the base fertilizer be sufficient, but also topdressing fertilizers must be strengthened during the fruiting period to ensure high yields.
Cucumber downy mildew is a destructive disease, which is generally controlled by chemical methods of spraying pesticides. According to experiments, taking pollution-free control measures can also achieve good results, and can also reduce expenses and improve quality. The main measures are:
1. High temperature stuffy shed. Choose a sunny day at noon to seal the greenhouse, so that the temperature in the shed quickly rises to 45 degrees, keep it for 2 hours, and let the air cool down. Generally, one time of stuffy shed can control the disease for 10 days. Note that the day before implementing the high-temperature stuffy shed should be watered enough.
2. Heating and dehumidification. Increasing the ground temperature in the greenhouse and reducing the humidity in the greenhouse is conducive to the growth of cucumbers, and can effectively inhibit the occurrence of downy mildew. The method is: raise the temperature of the shed to 30-32 degrees by sealing the shed in the morning. In the afternoon, let the air out to reduce the temperature to 20-22 degrees, and the humidity in the shed to 60%-70%. In addition, mulch film, rice (wheat) grass, furnace ash, etc. can also be used to cover all or part of the way to increase the ground temperature in the shed and reduce the temperature in the shed.
3. Foliar spray. During the growth of cucumbers in greenhouses, reasonable spraying of foliar fertilizers to supplement nutrients can quickly and effectively provide the plants with the required nutrients, promote the growth of cucumbers and improve disease resistance. Generally, it is sprayed once every 10 days or so, and 50 kg of mixed solution of nitrogen, phosphorus, potassium and boron is sprayed per mu each time. The preparation of the solution is to add 50 grams of urea, 100 grams of potassium dihydrogen phosphate and 100 grams of borax to every 50 kilograms of water. Boron should be dissolved with a small amount of hot water before the solution is prepared.
4. Spray sugar solution. According to research, the severity of downy mildew has a lot to do with the ratio of sugar to nitrogen in cucumber. During the growth period of cucumber, spraying a mixed solution of 1% sugar and 1% urea, the disease prevention effect can reach more than 80%. Generally spray 5-8 times.