Few countries can compete with Holland in the number of greenhouses and the volume of production grown in them. The experience of this country is also valuable with unique technologies for growing greenhouse plants.
The Netherlands is a small flatland country, stretching along the North Sea coast. Holland today occupies one of the leading places in the world in the production of agricultural and flower products grown both in open ground and in greenhouses.
Dutch agronomists believe that yield and light are related by a ratio of 1: 1, that is, yield is directly dependent on lighting
The climate of the Netherlands is considered maritime. There are no mountain ranges on the territory of this country capable of blocking the flow of cold air masses from the Atlantic. Winter temperatures here practically do not fall below 3 ° C, and the average summer temperature is 17 ° C. In addition, there are frequent gusty winds and rains. Not the most favorable conditions for the growth of crops. But the country for many years remains the world leader in the production of vegetables and flowers. And all because many years ago they relied on greenhouse farming here.
The light transmission capacity of modern greenhouses is 90%
The first greenhouses appeared in Holland in 1850 and were intended for the cultivation of grapes. In the middle of the XIX century, science has already proved that in heated rooms with glazed walls and roofs, the yield of all vegetables and fruits is much higher than in the open air.
The very first greenhouse for viticulture appeared in Westlandia - one of the most marshy areas. The calculation of scientists to create a favorable soil for growing grapes was very accurate. From the seashore to the construction site of the "warm glass house" several tons of sand were brought, which covered the swamp. The presence of a huge amount of moisture from the bottom in many ways saved the farmers money for watering the vines.
The first harvests, as historians testify, exceeded all expectations of agronomists. After that, the country decided to use glazed greenhouses for the cultivation of other fruit and vegetable crops.
The first half of the seventies of the last century is considered a point of reference in creating powerful industrial greenhouse structures that could withstand severe storms and hurricanes. It was in 1972-73. the territory of Holland shook under the weight of heavy hailstorms and frequent storm winds.
Structures that nature itself tested for strength were gradually improved. It was in those years that the standard NEN 3859 was developed, which modern greenhouse manufacturers are guided by now.
Engineers and agronomists are involved in the creation of greenhouses.
Greenhouse construction gradually modernized, new technologies were introduced. Today in Holland, the most famous manufacturer of greenhouses is the concern "Venlo" (Venlo). He is engaged in the construction and installation of internal heating systems, irrigation, ventilation of greenhouses, which extend to thousands of hectares. Representative offices of the company exist in many countries of the world.
Worldwide, this type of greenhouse is called "Dutch". I would like to highlight some of its features. Cases of all greenhouses are made of aluminum. They are very convenient and easy to assemble. Glazing uses a durable transparent coating called float glass. It possesses high light transmission and is almost invulnerable for extreme precipitation, such as, for example, large hailstones.
All Dutch greenhouses are equipped with special gutters that do not allow rainwater to seep through the glazing inside, and collect it in special tanks. Thanks to this innovative design, all farms in the country have a double benefit. They receive free tons of rainwater for irrigating greenhouse plants and thus save significant funds on paying for water from the aqueduct.
A typical Dutch greenhouse has such a frame
Another interesting development of engineers from the Netherlands are anti-fox terminals, which reliably fix all prefabricated hull structures.
The height of typical industrial greenhouses is usually 5 m or more. It all depends on the desire of the owner and the particular crops grown
To create an ideal microclimate in the autumn-winter and spring-summer periods, highly efficient greenhouse heating is required. For this, heating systems using alternative energy sources have been developed.
Huge deposits of hot geothermal waters in the Netherlands are used for internal heating of greenhouses. With the help of powerful pumps, water is pumped to the surface, cooled and distributed to heating devices.
Often used not only geothermal waters, but also purified industrial water.
After cooling, the water again goes underground, where it is again heated to its natural temperature.
Water circulates in a closed loop.
Solar collectors are also installed everywhere - on roofs, walls, not far from greenhouses. On special plates coated in black, which absorbs the energy of sunlight. It is converted to heat, uniformly heating the water, which circulates in aluminum tubes under dark glass plates. This hot water enters the radiators.
With such collectors greenhouse does not need heating
Heating is carried out by burning local natural gas.
Electricity for lighting and ultraviolet lamps, the light of which is detrimental to small pests on the leaves of plants, comes from solar panels or wind turbines.
Solar panels help destroy pests
These advanced technologies make it possible to create a temperature within the greenhouses that is acceptable and adjustable for each type of plant.
In large greenhouses of the Netherlands all types of vegetables are grown: tomatoes, paprika, cucumbers, cabbage, carrots and various types of greens.
Dutch agronomists also plant large volumes of strawberries, strawberries and many types of flowers, which require warmth for ripening and excellent growth. Here are applied the most unusual ways of growing vegetables and fruits. For example, for a full-fledged ovary of flowers of a tomato or paprika in greenhouses, they launch specially bred bumblebees, which pollinate them.
In the Netherlands, they mainly specialize in early ripening varieties of vegetables, which produce crops already 56-58 days after planting. These varieties were specially bred by local breeders. According to experts, it is possible to collect about 65 kg of tomatoes from 1 square meter. By the way, it was thanks to the experience of Dutch breeders that many hybrids of tomatoes, cucumbers and other vegetables that are popular in Eastern Europe were obtained.
Unpretentiousness and high yield - the main differences between Dutch tomatoes
Mineral wool impregnated with a special nutrient solution is used as a soil. This composition is placed in small plastic bags, where plants are planted. Carbon dioxide is supplied to the greenhouses using a generator. All functions of the root system power are controlled by a computer. Human intervention is required only in case of any technical failures.
However, the traditional method of cultivation of tomatoes and other vegetables in fertilized soil was not abandoned in the Netherlands. Although this method is most often used in private farms, however, vegetables grown there are not inferior in quality and taste, or even surpass their rapidly ripening counterparts.
One of the methods of growing strawberries is called Dutch.
Recently, the country switched to the cultivation of agricultural products in hanging containers and pots. This innovation mainly touched strawberries. The containers located at a height greatly simplify the collection of berries and facilitate the care of plants.
The method of year-round cultivation of garden strawberries (strawberries), based on the supply to the root system of each seedling of necessary nutrients and proper lighting, is already in full swing being introduced in greenhouses of Russia and other CIS countries.
In the Netherlands, there is no accurate statistics on what the total area of land allocated for greenhouses is: only approximate figures are named - 13-15 thousand hectares. The proportion of flowers that are bred under glass domes, accounts for 60% of all areas.
Roses of different colors, lilies, tulips, chrysanthemums, gerberas and many other varieties of flowers are grown in greenhouses. The required temperature in the greenhouses is created mainly due to the powerful lighting lamps and heating devices.
Every year at the beginning of spring millions of Dutch roses are sent to the CIS countries for the holiday of March 8
Virtually all of the country's flower production goes up for auction, and from there it scatters and disperses to all countries of the world in special aviation and car containers with a temperature of 4 ° C.
All the stems of flowers cut in the greenhouse are dipped in containers with a special chemical solution, which prolongs their life to 20 days or more. After that, each plant is subjected to expert evaluation, sorted and classified according to size and quality. Next, they are assigned a class - from first to third. These categories of flowers vary in price.
Dutch auctions are a joyful and exciting event for both sellers and buyers.
At the Dutch auction, where billions of flowers are sold every day, they are very cheap. But the price of modest bouquets increases three to four times when they are delivered to markets.
The total area of the Netherlands is 41.6 thousand square kilometers. This is slightly less than the Moscow region. However, by area in greenhouses the country ranks first in the world. Fruit, vegetable and flower products can satisfy the demand not only of the Dutch themselves, but also of millions of people in other countries.
A good role in this was played by the competent arrangement of greenhouses. In more detail with the techniques and methods of growing different crops, we will get acquainted in the following articles.