Drip irrigation in a greenhouse: device and system advantages

Drip irrigation in the greenhouse: device and system advantages

Agricultural work has always been very hard. But in large farms, mechanization helps out workers. It is quite possible to follow their example and carefully organize drip irrigation without unnecessary expenditure of your own strength..

Features and types of autowatering

The type of drip irrigation in the greenhouse is quite in demand. After all, caring for plants there also takes a lot of time and effort. However, it is not enough just to put pipes and containers and turn on the tap. It is also necessary to carefully understand the specifics of each type of liquid supply to plants. Only at the last stage are they united in the fact that water is provided in the form of drops, however, in the previous stages, everything is organized differently..

Actually, drip irrigation is implemented in such a way that the liquid is directed through the main pipelines to special tape parts and drippers. Such a system is capable of delivering small droplets of liquid to plants..

The strengths of such a system are as follows:

  • the earth will always have normal moisture;
  • positive conditions for the growth of weeds are not created;
  • water consumption is sometimes reduced by 30% compared to the usual regime.

But at the same time, the system turns out to be technically more complicated, which does not allow you to deploy it yourself. And the invitation of specialists makes the already high cost of the construction even more significant. In addition, greenhouse owners will have to continuously monitor whether the pipes are clean water. If the belts get clogged, there is simply no correct way to clean them without completely replacing them. And this is again a loss of money, time and, most likely, harvest (if this happens in the high season).

The engineers were clearly aware of this problem, of course. And so some of them tried to solve the problem in a different way. Nature, or rather, such a phenomenon as rain, became a clue for technologists. The liquid supplied from the source is transferred to the sprinkler units. Depending on the concept, they can be placed either close to the ground or closer to the roof..

As in the previous case, there will be no jets here.. The liquid is fed in neat drops. Each sprinkler, with all the differences between the individual models, is able to quench the thirst of plants over a large area. But this is where the merits end. But there is a threat that the greenhouse will become too humid, and the accumulation of liquid on the foliage can provoke its burns.

Having discovered such shortcomings, some specialists again turned their attention to the hints of nature. The solution was found in feeding the liquid directly to the roots. This is a very effective way, because all intermediate stages are bypassed, which usually lead to significant non-productive water consumption. It is difficult to install pipes underground. And although the soil is additionally aerated, and not just moistened, this circumstance complicates both the calculation and subsequent work..

Therefore, greenhouse owners often try to simplify their life by using an ordinary plastic bottle.. Holes are made in it and this container is buried next to the necessary plants. In terms of cost, this option is the most profitable, and if there are enough unnecessary bottles, no additional costs will be required. But here the subtlety is that this option is still rather semi-automatic, because you have to update the fluid in the tanks every few days. If the weather is dry and hot, sometimes it needs to be done more often..

Differences between systems are also made according to the type of water sources..

They are:

  • wells;
  • storage tanks;
  • wells for sand;
  • artesian wells;
  • water mains.

In any case, one must strive to ensure that the liquid is not noticeably hotter or colder than air.. Otherwise, the consequences for plants, whatever irrigation scheme is used, can be extremely serious. It is impossible to use water for irrigation directly from a well or well without preliminary exposure. Liquid from open reservoirs cannot be taken for another reason – it is dangerous due to microbial contamination and various poisonings.

To compensate for pressure surges in the water supply system, you will have to use special reducers; but filters are always installed, this is an indispensable condition for the correct operation of the system.

Advantages

We can talk for a long time about different types of drip irrigation. But it is also important to answer this question: how is it beneficial, how such an innovation will affect the cultivation of the same cucumbers, tomatoes or berry plants.

With micro-drip irrigation of plants, gardeners receive the following benefits:

  • facilitating household chores;
  • reduced bills for water consumption;
  • optimization of its consumption (without peaks that are inevitable with a one-time manual watering);
  • a significant reduction in the risk of diseases associated with waterlogging, with the ingress of water on leaves and stems, on fruits;
  • maintaining plants in decent shape even in the temporary absence of people.

The first factor is quite obvious – when there is no need to constantly walk with watering cans, buckets or a hose, this immediately releases the farmer’s strength.. A targeted supply of liquid specifically for specific plants allows you to achieve optimal fertility, sometimes spending significantly less water. At the same time, the crop ripens noticeably earlier than with the usual method, and its value even increases. Thanks to drip irrigation, irrigation of weeds is excluded (it is very difficult or even impossible for them to “intercept” the liquid that is so necessary for cultivated plants). An important advantage is also associated with the fact that the soil does not collapse, whereas with ordinary watering, moisture affects it unevenly, undermining the normal structure.

But the absence of a chaotic movement of water is beneficial in another respect – an important channel for the transfer of dangerous diseases from one plant to another is blocked. You can combine the use of drip irrigation and the supply of plantings with mineral additives in liquid form. Then the quality of the dosage increases significantly and at the same time it is excluded that the fertilizer does not get into the wrong place. In the hottest and sunniest summers, plants are insured against sunburn. Irrigation efficiency is not affected by wind.

Drip irrigation systems deliver liquid in such a way that the formation of a strong impermeable crust on the surface is impossible. Water is supplied evenly to all parts of the beds, so there will not be a situation when something is suddenly overlooked or overfilled. Subsequent gardening work can be carried out at randomly chosen times, without adapting to the irrigation schedule. Unlike transferring hoses, walking with buckets and watering cans, there is no risk of damaging plants, and there is no dirt. The time interval separating loosening from weeding increases significantly. There is only one drawback here, and that is conditional – increased costs at first and the need to carefully calculate everything.

System design

There is no doubt that the use of drip irrigation in a greenhouse is a completely rational step. But in order not to be disappointed in its advantages, it is necessary to correctly build the entire configuration of the irrigation complex. The decisive role in it is played, of course, by the lines supplying liquid to the plants. They can be made in the form of ribbons or tubes, but in both cases, the layout is carried out almost close to the rows of plants. The main difference is due to the fact that for some farmers, one-year lines are better, while others need the highways to operate for 5-6 years..

In most cases, irrigation pipes are made of polyethylene., and then the droppers themselves are set at a carefully calculated distance. These constructions are equipped with small-sized passages in the form of zigzags inside. Such a solution is quite correct and was chosen by the engineers quite deliberately, because in any other scheme the fluid pressure turned out to be too strong. Even inexperienced gardeners understand how this will affect the plants, especially the newly planted seedlings. Sometimes, instead of them, it is decided to install drip tapes, which are also formed from polyethylene, but these are already twisted in a special way and connected by the method of heat welding of structures.

A very important point in the production of such tapes is that the seam is deliberately made with small holes. They just allow you to apply liquid directly to the beds. It is recommended to lay the tape with drip channels upwards. The closer the layout is to a straight line, the more practical and reliable the whole system will be. Based on experience in a wide variety of conditions, drip tapes are much better than tubing, especially if the irrigated area is large.

But it is impossible to realize competent automatic watering with tapes or tubes alone. It is imperative to mount the main pipeline, from which the liquid will rush in the right direction.

The usual technique is as follows:

  • the tap at the source is placed at a height of approximately 1 m;
  • a hose is diverted from it, stretched along the beds of the greenhouse;
  • already connected to this hose is a pipeline that provides irrigation itself.

Recommended to use wire brackets to hold the hose. Thanks to them, an accidental shift is excluded. A pipe of a specially selected diameter and length is used as a pouring channel (this will be discussed below). Fine filtering systems are installed on the reservoir where the water is taken from. It is imperative to use a reservoir in order to exclude the impact of failures in the water supply.

The valve can be installed both in front of the filter and after it. In these two cases, such a device has the same meaning: it precisely regulates the watering time and the amount of water flow. The fertigation unit often plays an important role in the system. It is used only by those gardeners who decide to combine watering with fertilization and the use of other chemicals. Modern systems have been worked out for a long time and make it possible to guarantee the assimilation of all the necessary substances by plants.

All of the above applies to the automated version of drip irrigation of greenhouse plants.. But in some cases, the opportunities provided to them are simply redundant for farmers. So, with the organic method of plant cultivation, pesticides and liquid mineral fertilizers are almost not used. Therefore, there is no need for the corresponding nodes and their configuration. In addition, many are discouraged by the complexity of creating a full-fledged irrigation structure..

Therefore, various compromise solutions appear, including the use of plastic bottles and other improvised means. The disadvantage is that all types of drip irrigation need careful control. Both manual and automatic complexes need to be constantly tuned and reconfigured, guided by the needs of plants in actual weather.

Differences in the form of finite elements (droppers) are associated with:

  • types of cultivated plants;
  • greenhouse area;
  • available financial resources.

Their main gradation implies division into compensated and uncompensated ones. In the second option, the flow of liquid in the final part of the bed is less than at its beginning. But compensated devices allow you to distribute water more clearly even with unequal pressure. It is the compensated devices that make it possible to avoid the negative effects of significant differences in height. Such devices cannot pump out water completely even at the time of stopping work..

Strictly speaking, this is not a disadvantage. Conversely, the next start-up does not waste time pushing the air out. In some cases, more expensive systems are used, each of which throws water onto several plants at once..

Regardless of the type of mounted system, it is required to make a collapsible dropper. Almost always, the distance between the droppers should be 0.3 m. But there are plants that need to be irrigated according to a different scheme. When supplying water to perennial crops, it is best to use spiders. Water mains for them must be formed in a suspended version. Root crops are irrigated at a distance of 0.2 m, and the distance between irrigation points for melons and gourds is 1 m.

Calculation of the volume of water

But it is not enough to determine the design features, it is also required to determine how much water will pass through the homemade micro-droplet channel. This is necessary to assess the amount of fluid. Subsequently, such data will make it possible to establish which source is best, how to use combinations of these sources in different situations..

But there is another nuance that is not taken into account by many people, although it causes a lot of failures. The fact is that in pursuit of the maximum economy of water resources, their consumption is often made unreasonably low, not meeting the needs of plants. It is these errors that give the basis for the statement about the incorrectness of drip irrigation..

Competent calculation implies an analysis of such circumstances as:

  • internal air temperature;
  • its moisture level;
  • type and variety of culture;
  • backlight intensity.

If you turn to the specialized literature, you can simply be frightened of the difficulties. Professional agronomists, describing this technique, freely operate with the “Pennmann equations”, refer to the use of tensiometers and potentiometers. Reputable firms, organizing greenhouse farms, use very sophisticated equipment that allows you to control even fluctuations in the size of the stems during the day. But even experienced specialists do not yet have a methodology that would make it possible to predict fluid costs in advance. Therefore, trying to reproduce the same level in a private economy is both difficult and expensive, and therefore unjustified.

The way out is the use of data on the need for individual crops in water, which are given in botanical and agrotechnical reference books. However, it will not be possible to limit ourselves to such information. It is very important to consider what is the minimum moisture content of the land in which the plants are grown. Depending on the chemical composition and mechanical structure of soils, such a characteristic can be very different, and its exact value can only be established in a laboratory..

The next important calculation parameter is the frequency of drip irrigation.. To calculate it, in addition to the minimum moisture capacity, you need to know its limiting indicator, as well as the so-called wilting moisture. The minimum moisture capacity is determined as follows: this is the state of the soil when the capillaries are 100% saturated with water, and air is present in the pores. It is this balance that is considered the best, and it is precisely for it that all farmers should strive. Limiting moisture capacity is called a state when both pores and capillaries are abundantly moistened..

As for the wetness of wilting, everything is also simple here, despite the seeming scientific nature of the term. This is a situation in which the soil is very dry and the pressure difference does not allow for the osmotic flow of water. As a result, any culture quickly loses its tone and even dies. Worst of all, even increasing the intensity of watering or the subsequent addition of moisture does little to improve the situation. For dense clay or heavy sand, the highest moisture capacity is almost the same as wilting moisture.

Therefore, by watering the plants every 48 hours, you can easily oversaturate the earth with water. However, the soil sometimes dries up on the next day. But loams can be irrigated more flexibly, using water every 2-3 days..

Variables for accurate calculation of water demand are:

  • water consumption by individual plants of a particular variety;
  • number of rows;
  • planting density;
  • duration of daily watering.

Automation: pros and cons

But having determined the exact need for water, you should not dwell on this. Next, you need to determine how this flow will be controlled – automatically or not..

The advantages of automatic watering are obvious:

  • it is easier;
  • it is easier physically;
  • a lot of time is released;
  • systems, especially equipped with timers, prevent drying out of plants.

But in reality, not everything is as simple as it seems. A high-quality automatic irrigation system is quite expensive. To install and debug this complex, it is almost always required to involve professionals. You will need to carry out maintenance at least every six months. In addition, not everywhere there are water sources necessary in terms of power and characteristics, in case of destruction (depressurization) of the system, a “swamp” appears instead of a greenhouse and careful design and consideration of the smallest nuances are necessary.

Water supply: options

When the automatic or manual mode of operation of drip irrigation systems is selected, it is necessary to determine how the liquid will be supplied. Power is almost never used directly from a water pipe or a well, more often barrels or even cisterns are used.

When planning a pipeline network, they are guided by:

  • the relief of the area where the greenhouse is located;
  • soil conditions;
  • generally accepted norms for the correct organization of irrigation.

Obtaining water from underground sources is more expensive and more difficult than connecting to an already stretched water supply. The advantages of this option are most often the greater purity of the liquid. But it is still very important to carry out its chemical analysis. Often, even wells drilled into the sand bring unpleasant surprises..

It is also important to decide on the choice of drip irrigation systems using natural pressure and equipped with pumps. In both cases, we are talking about structures designed for irrigation of a large area. If the water pressure is low, it will not be possible to water beds longer than 10 m.And if the system is designed for a significant flow rate, it turns out to be more complicated and is created only with the help of specialists.

DIY making

Schema and markup

Having dealt with all the basic requirements for water consumption and the design of an irrigation system, it is necessary to think over the organization of irrigation in space. If the supply of liquid will occur naturally (by gravitational pressure), then usually a single trunk line with outlets is enough. But most farmers are not content with the functionality of the simplest system. It is possible to make the correct scheme only after the location of the plants in space has been determined..

It is recommended to reflect such points in the scheme as:

  • placement of main pipes;
  • places of installation of locking fittings;
  • positions of drip tubes and stand-alone drippers.

Layout of pipe equipment or hoses can take place on the ground, underground, or on special supports. The first type is relatively simple and lightweight. However, it will be necessary to limit the use of only solar-impermeable pipelines. Direct insolation creates favorable conditions for the development of various microorganisms. And when they are preparing for the arrangement of underground water supply channels, they will have to select material with reinforced and thickened walls..

In a completely flat area, it is recommended to place the hoses at a certain slope. Before installation, it is also required to mark where each connection will be located. This requirement is related to the need to calculate how many components are needed. And it is advisable to pay maximum attention to this moment..

Tools and accessories

To independently organize drip irrigation in the greenhouse, it is recommended to use main plastic pipes. Such structures are lightweight, cost relatively little, and can be used to irrigate perennial crops. In the absence or insufficient power of the water supply system, the best choice is to install the tank, which is placed at a height of 2 m. But you need to use only those structures in which the water is in minimal contact with air and sunlight. Otherwise, the development of algae is inevitable..

According to generally accepted technology, the set of installed parts also includes filters and starter connectors.. The number of connectors and their types can vary significantly. To equip the system to the end correctly, you must finally take a pump with the required parameters. Strictly speaking, there are no special pumping devices for this purpose, so farmers use any equipment capable of pumping cold liquid in the required volume. The main importance in the selection are the intensity of the passage of water and the height to which it will be pumped.

Usually, if the demand for irrigation does not exceed 100 liters per hour, pumps designed for heating systems are used. It should be borne in mind that most drip tapes are designed for a maximum pressure of 1 atm. For products with thickened walls, this figure is twice as high. And even to external droppers, it is undesirable to apply a pressure of more than 4 atm. However, not everything is as simple as it seems. After all, the waterway can be quite long, sometimes there are changes in the trajectory and intersections. All this leads to the fact that it is impossible to underestimate the reduction in pressure when the fluid moves towards the target. Therefore, in reality, you have to buy significantly more powerful pumps..

Procedure

Looking ahead, I must say that even when installing a system of completely new components, it must be flushed. To do this, remove the plugs and let the liquid pass until the moving stream is completely clean. Installation begins with the main pipes, which are stretched parallel to the tracks. To the left and right of these highways, wiring is organized. To connect such dissimilar segments, collapsible docking devices are used..

Until this stage of work is completed, it is strictly forbidden to connect tapes or tubes with distribution sections.. When the required section of the pipe is cut off, a plug is mounted on it from one end, and a transition to the water supply line through the tap is created from the opposite end. The recommended cross-section of holes for correct attachment of the connectors is 1.4 cm. It is advisable that the distance between the individual connectors adapt to the gaps between fits. Dispensing taps are supplied with a gasket, and a soapy water or silicone-based lubricant is usually used to install the starter connector..

Most people prefer to connect the filling line to the water supply with polyethylene pipes. From the crane to the last section of the pipeline, a collapsible connection is sometimes installed. But it should only be used when the use of the greenhouse is seasonal. Having rolled out the tape, the ends of the sleeves are tied to the distributing taps. This completes the preparation for work..

Ready-made kits

With all the simplicity of self-made drip irrigation systems, many farmers are still trying to purchase completely ready-made kits. You can understand them: after all, what a close-knit and trained team of engineers, technologists, agronomists and other specialists is working on is clearly more perfect than handicraft products. This superiority will be even more striking if we take into account the best technical equipment of the factories, where all this “splendor” is produced. To eliminate errors, you need to focus on the ratings and get acquainted with the reviews about certain designs.

Among the honored leaders in the supply of equipment for drip irrigation has been present for many years Gardena firm. She also supplies timers to automate the process as much as possible and make it almost independent of human effort. The firm says its designs help provide the same results as conventional irrigation, but using only 30% water. The liquid is supplied directly to the roots, and the equipment is extremely easy to use.

The range of supplied equipment includes:

  • full sets of droppers;
  • modular blocks for vertical gardening;
  • nozzles for spray hoses;
  • corner modules;
  • brackets and so on.

There are also basic kits for maintenance of beds, hoses for aboveground and underground highways. Micro drip irrigation systems are completely ready-to-use if they are installed correctly. Serious competition for this company can be apparatus “Vodomerka”. Kits of this series are suitable for work in conjunction with a water supply, and without it. Manufacturers declare that their products are capable of operating at extremely low head.

“Water strider” can adjust to the flow in the period from 2 minutes to 2 hours. In this case, the frequency is also set at the discretion of the owners. If you need to feed the system from the reservoir, you will have to buy and install it yourself.

The delivery set already includes:

  • splitters;
  • ball valves;
  • filters;
  • stubs;
  • pumps;
  • other required components.

For information on how to make a drip irrigation system in a greenhouse, see the next video.

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