To say that the field of greenhouse cost is the cheapest form of Plastic Single Span greenhouse, then it is inserted in the vault. It is a form of direct insertion into the ground with the curved sides of a circular tube. This kind of greenhouse is used a lot in central China and South China, and is favored by ordinary growers because of its low cost.

First, Tunnel greenhouse data parameters

Greenhouses generally span 6 meters to 9 meters, 1 meter to 2 meters high at the shoulder, 3.5 meters to 4.5 meters high at the top, and can be arbitrarily long according to the terrain.

This kind of greenhouse design data is relatively few, because its structure is simple, the foundation is usually inserted into the ground or simple concrete foundation, the skeleton is usually galvanized round pipe, the wind and snow resistance is relatively poor.

There are two vents on both sides of the greenhouse, which are attached with insect nets to prevent the pollution of insects with viruses and cause losses. Simple doors are set on both sides to provide simple protection and heat preservation.

Two, insert the use of greenhouses

The northern region can be used as a cold shed, the southern region can be used as a shelter for planting, can grow vegetables, ordinary flowers (non-high-grade potted flowers), edible fungus cultivation, etc.

Third, the cost of greenhouses and influencing factors

The main material inserted into the greenhouse is arch rod, longitudinal rod, shed film and other small accessories materials. The arch is available with diameters of 25, 32, and 48 tubes and thicknesses ranging from 1.5 to 2.0. The main types of longitudinal rod are 25 tubes in diameter and vary in thickness from 1.5 to 2.0. There are many kinds and brands of greenhouse film, such as po film, pe film, etc., the thickness is from 4 wire to 15 wire, the service life of the greenhouse film is from one year to eight years. Therefore, there are many differences in the cost of greenhouses, ranging from 5 to 7 dollars per square meter.

This type of greenhouse still has a large market share because of its low cost and simple installation, but it is worth noting that it is best not to buy cold galvanized skeleton material, which will rust in one or two years. It is necessary to choose hot galvanized skeleton material to drink products.

As for the comparison between NFT (Nutrient Film Technique) and DWC (Deep Water Culture), they are both popular hydroponic systems used for cultivating plants. Both methods provide a constant supply of water and nutrients to the plants without the need for soil. However, they have some differences:

1. NFT: NFT is a hydroponic system where a thin film or stream of nutrient-rich water is continuously circulated over the bare roots of the plants. The roots are exposed to the air and are suspended in channels or gullies. NFT systems require a slope to allow the nutrient solution to flow and are suitable for growing leafy greens and herbs. They require careful management of nutrient levels and flow rates to prevent drying out or waterlogging of the roots.

2. DWC: DWC is a hydroponic system in which plant roots are submerged in a nutrient-rich solution. Plants are typically grown in net pots that are suspended in a reservoir filled with the nutrient solution. Air stones or diffusers are used to provide oxygen to the roots. DWC systems are relatively easy to set up and are suitable for a wide range of plants. They can support larger plants and generally require less maintenance compared to NFT systems.

Choosing between NFT and DWC ultimately depends on factors such as the types of plants you want to grow, the available space, your level of experience, and personal preferences. Both methods have their advantages and disadvantages, so it's important to consider your specific needs and resources to make an informed.

1.     Ageing
Usually we do a hand tear test to determine whether the film has aged. In addition, we can test different places to see whether it is local aging or overall aging. The most common problem is that farmers use sulfur or halogen ( Cl, Br , etc.), which makes the UV stabilizer added to the film lose its effectiveness, thereby accelerating the aging of the film. When the film contacts iron, wood, PVC , etc., it will also cause the film to age faster.
(Note: To prevent premature aging of the film, please minimize the use of chemicals containing sulfur , chlorine, etc.)

2. Poor dripping
Usually we judge the dripping problem from the following aspects:
1 ) Check whether the installation is correct by checking the printed “This side faces the ground” on the film;
2 ) Production and installation time. On the one hand, it often takes a certain amount of time for the drip agent to take effect, especially in the very cold north. On the other hand, because the drip agent is constantly migrating from the inside to the outside, the drip agent on the surface is constantly washed away by water. After a period of time, the concentration of the drip agent is low to a certain level and eventually loses its effect.
3 ) Is the film installation angle appropriate? If the angle is too flat, the mist droplets on the film surface cannot flow down from both sides well, but will directly drip onto the plants.
4 ) Whether the film is installed well, for example, there should be no creases, because the droplets will stay in the creases, which is equivalent to continuously dissolving the drip agent there, and finally causing the area to fail prematurely.
5 ) The temperature difference between the inside and outside of the greenhouse and the humidity inside the greenhouse. When the humidity inside the greenhouse is not enough, the droplets cannot form a water film on the surface of the membrane, causing the droplet agent to precipitate and become powder attached to the surface of the membrane.

3. Films stick together
When the film is at high temperatures, the polymer chains untangle and fuse together, causing the film to stick together.
Different materials have different softening points. For example, the softening point of LDPE is about 95°C, the Vicat softening point of LLDPE is about 100°C , and the softening point of EVA is about 60-75°C . The higher the VA content, the lower the softening point.
In order to avoid this problem, the most important thing is to avoid exposing the rolled sheets to the sun and avoid high temperatures and high pressures.

   Intelligent fixed roof vents continuous PE film greenhouses are specially designed for the African market to produce year-round, with the advantage that the climate inside the greenhouse can be regulated by the cooling system.
How can the cooling system of our greenhouse be lowered to the temperature of normal plant growth?

Today Jamie from Xiamen Wellgain Greenhouse Engineering Co., Ltd. would like to shares with you an article about an economical effective cooling solutions of African intelligent fixed roof vents greenhouse for your reference.

1: External Shading System

An external shade net is a layer of netting installed 50cm or more above the top of the glasshouse parallel to the roof. It is the most direct way of cooling by blocking the sunlight directly outside.
The design focus of the shade net must be higher than 50cm above the roof in order to achieve the best effect and facilitate the flow of airflow in the lower part of the greenhouse.
This reduces the amount of solar radiation and thus heat entering the greenhouse.
The effectiveness depends on the type of shading material used and the percentage of light it blocks, to the best of our knowledge, external shading can reduce internal temperatures by about 5 ℃ ~ 7 ℃(FYI) depending on the intensity of the shading.
Greenhouse in the tropical regions, the indoor temperature is generally higher than the outdoor air temperature 4 ℃ ~ 6 ℃(just for reference).

Through the use of external shading screen system, the temperature inside the greenhouse can be lower than the outdoor temperature at the same time 1 ℃ (just for reference).

2: High pressure fogging system

High-pressure fogging machine cooling principle is to use the principle of evaporation and heat absorption is through high-pressure water beads into 0.165mm diameter spray, through evaporation to take away heat.
This system uses high-pressure pumps to create a fine mist or fog of water droplets that evaporate quickly. The evaporation process absorbs heat from the air, thus cooling the environment. The reduction in temperature due to a fogging system can vary greatly depending on the external temperature and humidity levels, but reductions of 3 ℃ ~ 6 ℃(just for reference) are common, with greater reductions possible under ideal conditions.
Combining an external shading system with a high-pressure fogging system in a greenhouse can be highly effective in controlling temperatures, especially in a tropical climate like that in Africa regions which the humidity is not high.
The humidity in the greenhouse may reach 95% or more after running of high pressure spraying, but after 1 hour to 2 hours, the humidity in the greenhouse will be reduced back to the original humidity(just for reference).

Celery is an annual or perennial herb, rich in vitamins, minerals, flavonoids and volatile oil compounds, is one of the important edible and medicinal vegetables.

In facility cultivation, the development of celery industry is restricted by diseases, lack of nutrients and high residue. Soilless cultivation can provide a good growing environment for crops, reduce the occurrence of pests and diseases, and has the advantages of saving labor, fertilizer and water, so it has become an important mode of vegetable cultivation development. Nutrient solution is an important environment for the survival of hydroponic vegetables. Different nutrient solution formulations and concentrations have important effects on the growth, quality and yield of vegetables.

Calcium is an essential nutrient for plant growth, calcium deficiency or calcium concentration is too high will affect the normal growth of plants, celery calcium deficiency will lead to black heart disease.

Treatment with 1.0mmol·L-1 calcium concentration was beneficial to increase the yield of celery in hydroponic culture, and treatment with 1.5mmol·L-1 calcium concentration was beneficial to improve the quality of celery in hydroponic culture.

Greenhouse Tomato Cultivation in Coir-filled Grow Channels: The Art of Precision Drip Irrigation Management

In modern greenhouse cultivation, the coir-filled channel system combined with drip irrigation has become the benchmark technology for high-quality tomato production. This cultivation method perfectly integrates the physical advantages of growing media with the control benefits of precision irrigation, and is being increasingly adopted by professional growers worldwide.

1. Core Components of the Coir Channel System

Grow Channels:

• Recommended "H" or "V" shaped channels

• Width: 25-30cm

• Depth: 15-20cm

Coir Substrate:

• Select coarse-structured coir with fiber length of 1-2cm

• Bulk density: 0.06-0.08g/cm³

Drip Irrigation System:

• Includes primary filtration unit

• Pressure-compensating drip emitters

• EC/pH monitoring modules

Drainage System:

• Channel bottom designed with 1-2% slope

• Equipped with collection troughs and return pipes

2. Unique Advantages of the Technical Combination

Optimized Root Environment:

• Coir pore distribution:

  • Macropores (25%)

  • Mesopores (45%)

  • Micropores (30%)

• Oxygen diffusion rate 3-5 times higher than soil

• Root zone temperature fluctuation reduced by 50%

Precision Water-Fertilizer Management:

• Irrigation response time reduced to 1/3 of traditional cultivation

• Nutrient supply error controlled within ±5%

• Enables zonal differentiated fertilization

Enhanced Production Performance:

• Continuous harvesting period extended to 8-10 months

• Premium fruit rate increased to over 85%

• Water-fertilizer use efficiency improved by 40-60%

In fact, in the production of smart greenhouses, the lighting time is generally controlled according to the type of plants, and can also be adjusted by intermittent supplementary light or shading. By appropriately reducing the light intensity, prolonging the lighting time, increasing the proportion of scattered radiation, and alternating intermittent or weak light, the light utilization efficiency of plants can be greatly improved.

1. Photoperiod fill lamp

For crops that are sensitive to photoperiod in the smart greenhouse, when the dark time is too long and affects the growth and development of crops, artificial photoperiod should be increased. It is easier to adjust the light time than the light intensity. Artificial periodic supplementary light provides information for regulating crop growth and development, generally promotes flower bud differentiation, and regulates crop flowering. Therefore, the intensity of fill light is unnecessary, and the time and intensity of fill light depends on the type of plant.

2. Photoperiod shading
The purpose of photoperiod shading is to prolong the yield of crops and ensure the demand of short-day plants in the smart greenhouse for continuous dark periods, thereby regulating flower bud differentiation. Generally, the top and periphery of crops are tightly covered with black cloth or black plastic film for greenhouse. During the shading period of the light cycle, ventilation should be strengthened to prevent damage to plants caused by the high temperature and high humidity environment.
By introducing the regulation of light time in the smart greenhouse, the regulation of time in the greenhouse plays an important role in the growth of crops. I hope you can master the knowledge of smart greenhouse.

Hydroponic vegetables refer to vegetables that are cultivated under the traditional soil cultivation form, in which most of the roots grow in the nutrient liquid layer and only provide water, nutrient and oxygen through the nutrient liquid. Hydroponic leaf vegetables have the characteristics of short growth cycle, clean product, good taste and good benefit. The varieties of hydroponic vegetables are mainly leaf vegetables, such as lettuce, green vegetables, cabbage, water cabbage, amaranth, chicory and so on. Preparation of nutrient solution is the key technology for normal growth of hydroponic vegetables.

At present, the nutrient solution formula used in the production of leafy vegetables is 1122g calcium nitrate, 910g potassium nitrate, 272g potassium dihydrogen phosphate, 40g ammonium nitrate, 247g magnesium sulfate, 1.2g boron sulfate, 0.09g zinc sulfate, 4.2g iron chelate, 27.8g ferrous sulfate and 37.3g disodium ethylenediamine tetraacetic acid per 1t nutrient solution. Leaf vegetables are grown on substrate. Vegetable seedlings grow to the colonization stage, seedlings from the soil or soilless cultivation matrix, can be directly planted in the pipeline equipped with funnel filter, or through root treatment and then planted in the pipeline water, the specific treatment method:
1. Wash soil or other cultivated substrate with clean water to remove roots;
2. Cut off old or dead roots, dead skin and excess lateral roots;

3. Soak roots with hydroponic plant disinfectant for 15-20 minutes to sterilize and disinfect. 4. Rinse with water again several times before colonizing.

The production management
1.Temperature control Hydroponics leaf vegetable root growth environment is nutrient solution, the temperature of nutrient solution directly affects the speed of leaf vegetable growth, the appropriate nutrient solution water temperature is 15-18 ℃, the temperature is 18-23 ℃. In summer, with high temperature and strong light, leafy vegetables grow fast, have low nutrient content and poor quality. Moreover, the stems and leaves of leafy vegetables contain more moisture and are crisp and tender. Strong light or water vapor condensation droplets are easy to burn the leaves, causing spots on the leaves and reducing the commercialization. Therefore, in the production, fan wet curtain cooling system and shading net are used to achieve the purpose of ventilation and cooling, control the growth of leafy vegetables and ensure the quality. However, it should be noted that the indoor light time and intensity must meet the requirements of the growth of leafy vegetables. In the morning and evening, the shade net should be pulled up to increase the weak light time to increase the color depth and thickness of the leaves. In winter, the temperature of the nutrient solution is preheated to reach the temperature required for the growth of leafy vegetables.

2.Concentration regulation winter temperature is low, the growth of leafy vegetables is slow, in order to improve the growth rate, the concentration of nutrient solution can be appropriately high, but not too much nitrogen, so as not to cause the taste of leafy vegetables, reduce the quality. Leafy vegetables grow faster in summer, and nutrient solution concentration is slightly lower than that in winter. The growth rate of leafy vegetables can be controlled by increasing the number of cycles to improve their quality.

3.Timely liquid supply The time and times of nutrient solution supply mainly depend on the cultivation form, vegetable growth state and environmental conditions. In the cultivation process should be timely liquid supply to ensure adequate nutrient supply. The time of liquid supply is generally chosen in the daytime, and no or little liquid supply at night. The number of liquid supply in sunny days is more, and the number of liquid supply in rainy days is less. More when the temperature is high and the light is strong, less vice versa. Under normal circumstances, 2-4 times a day, each time hold in 30 minutes.

4. Replacement of nutrient solution The nutrient solution should be replaced timely after a period of use. Because nutrient solution in the process of use will gradually accumulate too much material hindering plant growth, nutrient imbalance, a large number of bacteria, resulting in root growth arrest, and even lead to plant death. To grow the vegetable with shorter cycle commonly, each crop changes nutrient fluid. At the same time, NFT Gutters and plastic pipes should be cleaned and disinfected once a year.

The experiment was carried out on hydroponic lettuce seedlings by using three seedling substrates, namely phenolic foam, sponge and mixed substrate, to explore the influence of different substrates on the seedling emergence and biological yield of lettuce seedlings.。

The results showed that the effects of different substrates were significantly different:
At the seedling stage,
The emergence rate of lettuce based on phenolic foam (T1) was the highest, reaching 98.13%.
The sponges (T2) were followed by 97.5%,

The lowest was mixed matrix (T3),
The speed of germination and seedling growth was in order of T2> T1> T3,
Leaf length and overground fresh weight were T1> from large to small. T2> T3;
The above ground fresh weight of lettuce was T1> after pipeline hydroponics. T2> The leaves of T3 and T1 are short and thick, and have good commercial properties.
Based on the comprehensive analysis of seedling cost, operation mode, lettuce environment and experimental results, it was found that phenolic foam substrate was more suitable for growing lettuce seedlings in subtropical hydroponic culture.