Drip irrigation in the greenhouse: the device and the advantages of the system
- Features and types of autowatering
- System device
- Calculation of the volume of water
- Automation: Pros and Cons
- Water supply: options
- Making your own hands
- Scheme and Markup
- Tools and accessories
Agricultural labor has always been very hard. But in large farms, mechanization rescues workers. Follow their example and carefully organize drip irrigation without unnecessary expenditure of their own forces is quite possible.
Features and types of autowatering
The type of drip irrigation in the greenhouse is quite popular. After all, caring for plants there also takes a lot of time and effort. However, it is not enough just to put the pipes and containers and open the faucet. We still have to carefully understand the specifics of each type of fluid supply to plants. Only at the last stage they are united in the fact that water is provided in the form of drops, but at the previous stages everything is organized differently.
Actually, drip irrigation is implemented in such a way that the liquid is directed through trunk pipelines to special tape parts and droppers. Such a system is able to deliver small drops of liquid to the plants.
The strengths of this system are as follows:
- the earth will always have normal moisture;
- positive conditions for weed growth are not created;
- water consumption is sometimes reduced by 30% compared with the normal mode.
But at the same time, the system turns out to be technically more difficult, which does not allow deploying it by hand. And the invitation of experts makes the already high cost of construction even more significant. In addition, the owners of the greenhouse will have to continuously monitor whether the clean water goes through the pipes. If the tapes are clogged, there is simply no correct way to clean them without a complete replacement. And this is again the loss of money, time and, most likely, the harvest (if this happens in high season).
Engineers were clearly aware of this problem, of course. And because some of them tried to solve the problem in a different way. A hint for technologists was nature, or rather, such a phenomenon as rain. The liquid supplied from the source is transferred to the spray units. Depending on the concept, they can be placed either near the ground itself or closer to the roof.
As in the previous case, there will be no jets here. Fluid delivery occurs in neat drops. Each sprinkler, for all the difference between the individual models, is able to quench the thirst of plants in a large area. But on this the merits are exhausted. But there is a threat that the greenhouse will become too humid, and the accumulation of fluid on the foliage can provoke its burns.
Having discovered such shortcomings, some specialists again paid attention to the hints of nature. The solution was found in the supply of fluid directly to the roots. This is a very effective way, because all the intermediate stages, which usually lead to significant overhead costs of water, are bypassed. Difficulties is the wiring of pipes under the ground. And although the soil is additionally aerated, and not just moistened, this circumstance complicates the calculation and subsequent work.
Because the owners of greenhouses often try to simplify their lives, using an ordinary plastic bottle. They make holes in it and bury this container next to the necessary plants. At 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 once every few days. If the weather is hot and dry, sometimes it needs to be done more often.
Differences between systems are carried out by the type of water sources.
- storage tanks;
- wells on the sand;
- artesian wells;
- water mains.
In any case, we must strive to ensure that the liquid was not noticeably hotter or colder than air. Otherwise, the consequences for plants, whatever the irrigation scheme used, may be extremely serious. It is impossible to use water for irrigation directly from a well or a well without prior exposure. Liquid from open reservoirs can not be taken for another reason - it is dangerous microbial contamination and various poisonings.
To compensate for the pressure jerks in the water supply system, special gearboxes will have to be used; But filters are always installed, it is an indispensable condition for the system to work properly.
You can talk a lot about different types of drip irrigation. But it is important to answer this question: how is it profitable, how will such an innovation affect the cultivation of the same cucumbers, tomatoes or berry plants.
With microdrop irrigation of plants, gardeners receive the following benefits:
- facilitating household work;
- reduction of water consumption bills;
- optimization of its consumption (without peaks, inevitable with one-time manual watering);
- a significant reduction in the risk of diseases associated with waterlogging, with the ingress of water on the leaves and stems on the fruit;
- maintaining plants in a decent way, 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 with a hose, it immediately releases the strength of the farmer. Purposeful supply of fluid specifically for specific plants allows to achieve optimal fertility, sometimes spending significantly less water. At the same time, the crop ripens much earlier than with the usual method, and its value even increases. Thanks to drip irrigation, weed irrigation is excluded (it is very difficult or even impossible for them to “catch” the liquid that crop plants need). An important advantage is connected with the fact that the soil does not collapse, whereas with ordinary watering, the moisture acts on it unevenly, undermining the normal structure.
But the absence of the 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. It is possible to combine the use of drip irrigation and the supply of plantings with mineral additives in liquid form. Then the quality of the dosage significantly increases and at the same time prevents the fertilizer from entering the wrong place. In the hottest and sunny summer, the plants are insured against sunburn. Irrigation efficiency is not affected by wind.
Drip irrigation installation serves the liquid so that the appearance of a solid 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 suddenly something is lost or flooded beyond measure. Subsequent gardening work can be performed at arbitrarily chosen times, without adjusting 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 the loosening from weeding increases significantly. The disadvantage here is only one, and that is conditional - the increased costs at first and the need to calculate everything carefully.
There is no doubt that the use of drip irrigation in the greenhouse is quite a rational step. But in order not to be disappointed in its benefits, you need to properly build the entire configuration of the irrigation complex. A crucial role in it is played, of course, by the supply lines to the plants. They can be made in the form of ribbons or tubes, but in both cases the layout is performed very close to the rows of plants. The main difference is due to the fact that some farmers have better one-year lines, while others need to have highways acting for 5-6 years.
In most cases, irrigation tubes are made of polyethylene., and then the droppers themselves are placed at a carefully calculated distance. These structures are equipped inside with small zigzag-shaped aisles. This decision was quite correct and was chosen by engineers quite consciously, because in any other scheme the pressure of the liquid was too strong. Even inexperienced gardeners understand how it will affect plants, especially newly planted seedlings. Sometimes, instead of them, they decide to install drip tapes, which are also formed from polyethylene, but these are already structures that are twisted in a special way and connected according to the method of heat welding.
A very important point in the production of such tapes is that the seam is intentionally made with minor holes. Just they allow you to apply the liquid directly to the beds. It is recommended that the tape is laid up with drip channels. The closer the layout to the straight line, the more practical and reliable the entire system will be. Judging by the operating experience in a variety of conditions, drip tapes are much better than tubes, especially if the irrigated area is significant.
But to realize a competent automatic watering is impossible only with tapes or tubes. Be sure to install the main pipeline, from which the liquid and will rush in the right direction.
The usual technique is as follows:
- the crane at the source is placed at a height of approximately 1 m;
- a hose is pulled away from it, stretched along the beds of the greenhouse;
- Already this hose is connected to the pipeline, which provides irrigation itself.
It is recommended to use wire clips to hold the hose. Thanks to them, there is no random shift. A pipe of specially selected diameter and length is used as a pouring channel (this will be discussed later). Fine filtering systems are installed on the tank, from where water is taken. It is imperative to use the tank to eliminate the impact of failures in the water supply system.
Installation of the crane can be made both before the filter, and after it. In these two cases, such a device has the same value: it precisely controls the irrigation time and the amount of water flow. A large role in the system often plays a block of fertigation. It is used only by those gardeners who decide to combine irrigation with fertilizer and the use of other chemicals. Modern systems are worked out for a long time and allow us to guarantee the assimilation by plants of all the necessary substances.
All of the above refers to the automated version of the drip irrigation of greenhouse plants. But in some cases, the opportunities offered to them are simply redundant for farmers. Thus, with the organic method of cultivating plants, toxic chemicals and liquid mineral fertilizers are almost never used. And because the need for the appropriate nodes and their configuration disappears. In addition, many are repelled by the difficulty of creating a complete irrigation structure.
Therefore, there are various trade-offs, including the use of plastic bottles and other improvised means. The disadvantage is that all types of drip irrigation need careful monitoring. Both manual and automatic complexes need to be constantly tuned and reconfigured, guided by the needs of the plants in actual weather.
Differences in the form of finite elements (droppers) are associated with:
- species of plants grown;
- greenhouse area;
- affordable financial means.
Their main gradation implies division into compensated and non-compensated. In the second embodiment, the flow of fluid in the final part of the bed is less than at its beginning. But compensated devices allow you to distribute water more clearly even at unequal pressure. It is compensated devices that allow to avoid the negative impact of significant height differences. Such devices can not pump out water completely, even at the time of stopping work.
Strictly speaking, this is not a disadvantage. On the contrary, during the subsequent start-up time is not wasted pushing air out. In some cases, use more expensive systems, each of which throws water to several plants at once.
Regardless of the type of the installed system, it is required to make a dropper of a folding design. 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 it is necessary to supply water to perennial crops, it is best to use spiders. Water mains for them must be formed in the suspended version. Root crops irrigate at a distance of 0.2 m, and the distance between irrigation points of melons and gourds is 1 m.
Calculation of the volume of water
But it is not enough to decide on the design features, it is also necessary to determine how much water will pass through the self-made microdrop channel. It is necessary to estimate the amount of fluid. Subsequently, such data will determine 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 the pursuit of maximum saving of water resources, their consumption is often made unjustifiably small, not meeting the needs of plants. It is these errors that give rise to the statement that the drip irrigation is incorrect.
Competent calculation involves the analysis of such circumstances as:
- internal air temperature;
- its moisture level;
- type and variety of culture;
- backlight intensity.
If you turn to the special literature, you can simply be afraid of the difficulties. Professional agronomists, describing this technique, freely operate on the "Pennmann equations", refer to the use of tensiometers and potentiometers. Solid companies, organizing greenhouse farms, use very sophisticated equipment that allows you to control even fluctuations in changes in the size of the stems during the day. But even experienced specialists do not yet have a methodology that would allow for predicting fluid costs in advance. Therefore, trying to reproduce the same level in a private sector is both difficult and expensive, and therefore unjustified.
The output is the use of data on the needs of individual crops in water, which are given in botanical and agrotechnical reference books. However, it will not be limited to such information. It is very important to consider what is the minimum capacity of the land in which plants are grown. Depending on the chemical composition and mechanical structure of the soil, this characteristic can be very different, and its exact value can be established only in the laboratory.
The next important calculation parameter is the frequency of drip irrigation. To calculate it, in addition to the minimum capacity, you need to know its marginal rate, as well as the so-called wilting humidity. The minimum moisture capacity is defined as follows: this is the condition 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 all farmers should strive for it. The maximum moisture capacity is called a state where both the pores and the capillaries are abundantly moistened.
As for the humidity of the withering, then everything is also simple, despite the seemingly scientific wisdom of the term. This is a situation in which the ground 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 an increase in the intensity of irrigation or the subsequent addition of moisture hardly corrects the situation. For dense clay or heavy sand, the highest moisture content almost coincides with the wilting humidity.
Therefore, watering the plants once every 48 hours can easily overwhelm the earth with water. However, the next day the soil sometimes dries out. But loam can be irrigated more flexibly, using water every 2-3 days.
Variables for accurate calculation of water demand are:
- water consumption of individual plants of a particular variety;
- number of rows;
- planting density;
- daily watering duration.
Automation: Pros and Cons
But having defined exact need for water, it is not worth stopping on it. Next, you need to determine how this thread will be managed - automatically or not.
The advantages of automatic irrigation are obvious:
- it is easier;
- it is easier physically;
- a lot of time is released;
- systems, especially equipped with timers, allow to eliminate the drying of plants.
But in reality, not everything is as simple as it seems. High-quality automatic watering system is quite expensive. To install and debug this complex, it is almost always necessary to involve professionals. It will take at least every six months to carry out maintenance. In addition, not everywhere there are water sources necessary for power and characteristics, in case of destruction (depressurization) of the system, instead of a greenhouse, a “swamp” appears and careful design and consideration of the smallest nuances is necessary.
Water supply: options
When the automatic or manual mode of operation of drip irrigation systems is chosen, it is necessary to determine how the fluid supply will occur. Food is almost never used directly from a water supply system or a well; barrels or even tanks are often used.
Planning a network of pipelines, focus on:
- relief of the plot where the greenhouse is located;
- soil conditions;
- generally accepted norms for the proper organization of irrigation.
Getting water from underground sources is more expensive and more difficult than connecting to an already stretched water supply system. The advantages of this option is often the greater purity of the liquid. But it is still very important to carry out its chemical analysis. Often, even wells drilled in the sand, bring unpleasant surprises.
It is important to determine the choice of drip irrigation systems that use natural pressure and are equipped with pumps. In both cases, these are constructions designed to irrigate a large area. If the water pressure is low, it will not be possible to water the beds longer than 10 m. And if the system is designed for significant flow intensity, it turns out to be more complicated and is created only with the help of specialists.
Making your own hands
Scheme and Markup
Having dealt with all the basic requirements for water consumption and the design of the irrigation system, it is necessary to think through the organization of irrigation in space. If the flow of fluid will occur naturally (gravitational pressure), then usually a single trunk line with taps is enough. But most farmers are not satisfied with the functionality of the simplest system. It is possible to make the correct scheme only after the location of plants in space is determined.
It is recommended in the scheme to reflect such moments as:
- placement of main pipes;
- the installation location of the locking valve;
- positions of drip tubes and isolated droppers.
Layout of tubular equipment or hoses can occur on the ground, underground, or on special supports. The first type is relatively simple and easy. However, it is necessary to limit the use of only impermeable to sunlight pipelines. Direct insolation creates favorable conditions for the development of various microorganisms. And when preparing for the arrangement of underground water supply channels, it is necessary to select a material with reinforced and thickened walls.
It is recommended to put the hoses under one or another slope on a completely flat area. Before installation, you also need to mark where each connection will be located. Such a requirement is connected with the need to calculate how many components are needed. And now it is desirable to pay maximum attention to this moment.
Tools and accessories
To independently organize drip irrigation in the greenhouse, it is recommended to use plastic trunk pipes. Such constructions are light, cost relatively little and can be used to irrigate perennial plantings. In the absence or insufficient capacity 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 water is minimally in contact with air and sunlight. Otherwise, the development of algae is inevitable.
According to generally accepted technology, the kit of installed parts includes more filters and start connectors. The number of connectors and their variations can vary significantly. To equip the system to the end correctly, you must finally take the pump with the necessary parameters. Strictly speaking, special pumping devices for this purpose do not exist, therefore, farmers use any equipment capable of pumping cold liquid in the required volume. The main importance in the selection have the intensity of the passage of water and the height at which it will be pumped.
Usually, if the need 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 pressures of a maximum of 1 atm. For products with thickened walls, this figure is twice as high. And even on external droppers it is undesirable to give a pressure more than 4 atm. However, not everything is as simple as it seems. After all, the water route can be quite long, sometimes there are changes in the trajectory and intersection. All this leads to the fact that it is impossible to underestimate the reduction in pressure when fluid moves to the target. Therefore it is necessary in reality to buy significantly more powerful pumps.
Looking ahead, I must say that even when installing a system of completely new components, it is imperative to wash it. To do this, remove the plugs and let the fluid through until the moving stream is completely clean. Installation begins with the main pipes, which stretch parallel to the tracks. To the left and to the right of these highways distributing is organized. Collapsible docking devices are used to connect such heterogeneous segments.
While this stage of work is incomplete, it is absolutely impossible to connect tapes or tubes with distributing sections. When the necessary section of the pipe is cut off, a plug is mounted on it from one end, and from the opposite side a passage to the water line through the tap is created. The recommended cross-section of the holes for correctly attaching the connectors is 1.4 cm. It is advisable that the distance between the individual connectors be adapted to the gaps between the landings. Distributing taps are supplied with a sealing gasket, and when mounting the start connector, a soap solution or silicone-based lubricant is usually used.
Most people prefer to connect the bottling line to the water supply with polyethylene pipes. From the crane to the last section of the pipeline is sometimes put collapsible connection. But it should be used only when the use of the greenhouse is seasonal. Rolling out the ribbon, the ends of the sleeves are tied to the distributing cranes. In this preparation for work, in essence, is completed.
With all the simplicity of self-production of drip irrigation systems, many farmers are still trying to purchase ready-made kits. You can understand them: after all, what a cohesive and prepared team of engineers, technologists, agronomists and other specialists are working on is clearly more perfect than handicraft products. This superiority will be even more striking if we consider the best technical equipment of the factories, where all this “splendor” is produced. To eliminate errors, it is necessary to be guided by ratings and get acquainted with reviews of various structures.
Among the honored leaders in the supply of equipment for drip irrigation for many years present Gardena. It also supplies timers to automate the process as much as possible and make it almost independent of human efforts. The company claims that its designs help to ensure the same result as with ordinary watering, but using only 30% water. The liquid is supplied directly to the roots, and it is extremely easy to use the equipment.
The range of equipment supplied includes:
- full sets of droppers;
- modular blocks for vertical gardening;
- nozzles for spray hoses;
- corner modules;
- brackets and so on.
There are also basic sets for maintenance of beds, hoses for aboveground and underground highways. Micro-drop irrigation systems are fully ready for use if they are mounted correctly. A serious competition to this company can make devices "Vodomerka". Sets of this series are suitable for work and in conjunction with plumbing and without it. Manufacturers claim that their products are capable of operating at extremely low head.
"Vodomerka" can adapt to flow in the period from 2 minutes to 2 hours. At the same time, 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 has already:
- ball valves;
- other required components.
How to make a drip irrigation system in the greenhouse, see the following video.