Calculation and installation of an automated drip irrigation system from a barrel

The dosing unit works very simply: when the siphon bottle fills up, the water is quickly discharged through the siphon tube into the irrigation system, distributing it along the irrigation tubes. If there are several such tubes, an additional bottle—a receiver-distributor—is required. Water from the siphon flows into it. The volume of the receiver must be equal to the volume of the dosing unit. However, even if there is only one irrigation tube, the dosing unit works more reliably with a receiver-distributor.

Now you need to calculate the water supply rate. Time it. For example, the bottle fills in 15 minutes. This means 4 bottles of water are supplied per hour, i.e., 8 l. The irrigation time is from 10:00 to 17:00, totaling 7 hours.

There are 20 plants in the garden bed connected to the irrigation system. Each plant will receive an average of 2.8 l. To reduce the water supply, you can insert a nozzle—a piece of thinner tubing or wire insulation—inside the upper supply tube.

This means a 200 l barrel of water will last for 3.5 days. But this amount of moisture is excessive. Therefore, use the "nozzle" to regulate the water supply so that the consumption is approximately 2 l per plant. This amount of moisture is quite sufficient. In this case, the barrel of water will last for about 5 days. In reality, it will last even longer, as the pressure drops when the water level in the barrel decreases, and the system begins to "save" water. The less water there is, the more economical the consumption.

For one adult cucumber plant, 1—2 l of "drip" water per day is quite sufficient (with well-mulched soil). For tomatoes and peppers, the rate is half that.

The system will work reliably if you take its disadvantages into account.

The system must be constantly monitored. For if there is an excess of water, we have water waste and soil erosion, and if the water supply stops for a couple of days in hot weather, the roots of the plants, located mainly in the surface layer of the soil which is always moist, may die.

The system does not run from a high-pressure water main but is supplied with water from a barrel by gravity. Drippers have small openings, so they often get clogged. Cleaning them is easy—remove and blow them out or wash them. You cannot enlarge the openings, because in that case, the water will be distributed unevenly, and it may not reach the final nozzles at all. Therefore, take some measures to prevent nozzle clogging:

• install a filter at the system inlet—a fairly large piece of foam rubber placed on the inlet end of the hose in the barrel is sufficient. In case of clogging, it is easy to remove and wash;
• do not allow algae to grow, as they also often clog the nozzles. To prevent this, deprive them of light by covering the barrel with a lid and covering the transparent parts of the system with foil;
• keep all intermediate containers—the dosing unit and the receiver-distributor—tightly closed at the top so that insects, which can also clog the nozzles, do not get inside.

After these measures are taken, although the need for periodic cleaning remains, this operation takes significantly less time.

For novice vegetable growers, for irrigation of potted plants, it is advisable to assemble a structure consisting of several water-conducting pipes with small holes in their walls. They should be made in such a way that, after the system is installed, each one is positioned above a separate plant pot.

Often, the holes of drip irrigation elements are:

• covered with attachments;
• connected to small-diameter tubes that lead directly to the crops.

In some cases, solenoid valves and a timer are included in the automatic irrigation system for greenhouse and hotbed plants. This allows for the regulation of the volume, duration, and timing of the water supply.

When using an automatic irrigation system, regular inspection of the plants should be carried out. As is known, different plants require different amounts of water; however, an automatic irrigation device is incapable of providing selective irrigation, and all plants receive an equal volume of moisture. If there is an insufficient or, conversely, an excessive amount of water reaching a particular plant, the supply must be adjusted.

Any book on indoor floriculture states that for flowers, you can use meadow, forest, or garden soil, but never greenhouse soil. Why? Because the soil in a greenhouse is usually very dense and not very dark. And any guide recommends changing it periodically. But that involves tons of soil that must be obtained from somewhere. We do not change the soil in the garden and we get a good harvest, but greenhouse soil is something special. What happens to it in a greenhouse that makes it unsuitable?

In a greenhouse, during fair weather when the sun is shining, the surface of the soil warms up quickly. We open the doors and vents. The wind carries away humidity from the plant leaves, as well as from the soil surface. Its top layer dries out and overheats, soil biota dies off, and roots suffer. Upon seeing wilted vegetable leaves, we increase ventilation by opening doors on opposite sides. A draft leads to even greater moisture loss, and plants "drink" the remaining water from the soil, wilting even more.

It is quite natural that we begin to irrigate the plants. From a watering can, from a hose — however it works, by any available means. The plants revive slightly, but the soil receives a temperature shock: moreover, fluctuations in humidity, mineral top dressing, and constant washing away of everything washable from the surface take their toll. Earthworms and other soil inhabitants leave. Only insoluble mineral particles remain in the soil — sand and clay clods, which stick together upon drying.

Why greenhouse soil degrades and how its natural nutrition is structured

In a greenhouse, the soil is under harsh conditions. The roof completely blocks the access of natural organic matter in the form of falling leaves, while weeds and dying plant parts are carefully removed during weeding. At high temperatures of protected ground, initial organic substances decompose much faster than in an open field. As a result, the soil quickly loses its structure, becomes depleted, and eventually becomes unsuitable for growing crops. Obtaining a good harvest solely through the application of mineral fertilizers to "dead" soil will not succeed.

High-quality soil should be fluffy, light, and dark. Its structure is ensured by undecomposed organic matter, and its deep dark color by humus. This is a product of the deep decomposition of cellulose and lignin, representing a complex mixture of high-molecular polymers. Its composition includes:

• humin;
• ulmin;
• humic acids;
• fulvic acids.

In living chernozem, invisible work is constantly underway to prepare nutrition. Microflora converts hard-to-reach compounds, such as insoluble phosphorus or atmospheric nitrogen, into an assimilable form. In return, plants release organic matter through their roots, feeding the inhabitants of the rhizosphere. Over millions of years of evolution, this balance has been honed to perfection: salts are released in microdoses every second and are immediately absorbed by the roots. In living soil, the following work:

• various types of bacteria;
• algae;
• fungi;
• insects;
• worms.

Rules of mineral nutrition: risks of overdose and precise application

An alternative cultivation method is hydroponics on sand, expanded clay, or sawdust, as well as aeroponics, where roots hang in the air and are periodically irrigated with a nutrient solution. These technologies are used in large greenhouse complexes, but they require strict laboratory control. Since there is no soil buffer, a deficiency of just one micronutrient out of a dozen necessary ones will quickly destroy the entire harvest. In standard soil cultivation, dosage accuracy is also important, as an excess of fertilizer is always more dangerous than a deficiency.

The application of dry complex granules during digging solves the problem only partially due to the different solubility of the components. Nitrogen and potassium instantly pass into the soil solution and are quickly leached from the root zone. Phosphorus, conversely, dissolves and is released very slowly. As a result, the concentration of elements in the soil makes a sharp jump and then falls rapidly.

To determine the real presence of available substances, an aqueous extract from a soil sample is made in an agrochemical laboratory. All insoluble residues are considered unavailable for current plant nutrition. To maintain the balance of elements at an optimal level and not burn the roots, mineral top dressing should be supplied in microdoses. The best practical solution for a greenhouse is to add dissolved fertilizers in low concentrations during each irrigation via a drip irrigation system.

The black color of the soil indicates a high humus content and active soil biota. However, if the soil remains dark but starts to compact, this is a critical signal. It is necessary to urgently add organic matter; otherwise, the soil will quickly lose its soil fertility.

To improve soil structure, you can populate the beds with beneficial bacteria and earthworms. Keep in mind that these organisms require strict adherence to maintenance techniques. In an overheated greenhouse or in case of a moisture deficit, these biological assistants will simply stop working.

Methods for disinfecting greenhouse soil and structures

With intensive use of a greenhouse, pathogens and pests quickly accumulate in the soil. These include pathogens of cucumber bacteriosis, cauliflower rot, tomato bacterial canker, and spider mites. Without regular replacement or disinfection of the soil, it will be impossible to protect new plantings.

• Soil heating temperature — up to 100 °С
• Application rate of bleaching powder for soil — 100–200 g/m²
• Lime consumption on acidic soils — 4 kg/m³
• Infusion time of the solution for structures — 2–4 hours
• Soil quarantine for white rot — 4 years

To sanitize the soil biologically, follow these steps:

1. Remove the contaminated soil from the greenhouse and pile it up to a height of 1 m.
2. Layer the soil with fresh manure or drench it with liquid manure.
3. Add lime to acidic soil at a rate of 4 kg/m³.
4. Leave the pile for 2 years (4 years if contaminated with clubroot or white rot), turning the soil and removing weeds annually.

The thermal method is suitable for preparing soil for transplants. Moisten the soil, place it in boxes, and heat it on a metal tray or iron sheet, stirring continuously. Alternatively, you can drench the soil twice with boiling water, but this will require a long drying period.

Chemical disinfection with bleaching powder destroys most pathogens, including cabbage clubroot. Distribute the dry preparation evenly over the surface and incorporate it into the 20 cm thick soil layer using a rake. This method requires precise adherence to application timing.

Disease spores and pests successfully overwinter on the frame and glazing parts. Preventive disinfection of greenhouses and hotbeds is carried out with a bleaching powder solution in two stages. The first time, surfaces are treated immediately after harvesting">harvesting, and the second time after the final cleaning of the structures.

To disinfect frames and internal surfaces, prepare the working solution:

1. Dissolve 200–300 g of bleaching powder in 10 l of water.
2. Let the mixture stand for 2–4 hours.
3. Drain the clarified liquid from the sediment.
4. Spray the structures or treat them with a bast brush, thoroughly drenching the cracks.