Greenhouse hydroponic irrigation

To be honest, every time I hear about “ideal hydroponic systems”, I remember how many greenhouses in our region were installed by Dutch installations and half of them were rebuilt after a season. Not because it’s bad, but because they don’t take into account that water from a well gives +12°C even in summer, and not +18 as in their calculations. This is the main pitfallgreenhouse hydroponic irrigation— it seems that everything has been calculated, but small nuances on the spot always make adjustments.

Why standard solutions don't work

Take, for example, a drip irrigation system with EC sensors - in theory, everything is simple: you control the electrical conductivity, add fertilizer. But in practice, in the heat, evaporation from the surface of the substrate distorts the readings, and by the evening the plants receive a concentration 30% higher than normal. You have to either install additional shadow screens or switch to pulse irrigation adjusted by air temperature.

Speaking of substrates, many still use coconut fiber, although in our harsh continental climate the perlite-vermiculite mixture has proven to be better. It cakes less due to changes in humidity, and the salt balance is easier to control.

This is especially problematic with tomatoes - they are sensitive to pH changes during the day. You have to either split the supply of nutrient solution into 8-10 short cycles, or install buffer containers with constant recirculation. By the way, it is precisely for such cases thatShandong Linyao Intelligent Agriculture Technology Co.,LtdThere are acidification modules with automatic correction - not a panacea, but at least it removes the human factor.

Equipment that really works

After several unsuccessful experiments with 'smart' valves, we came to the conclusion that it is better to use simple electromechanical valves with manual override. Yes, it’s less technologically advanced, but when the voltage surges (and in our rural areas this is the norm), the system does not freeze in a half-open state.

Filtration is a different story. Disc filters are good until the first serious contamination of the water, after which their performance drops significantly. Although mesh ones require frequent washing, they are at least predictable. In the latest project for a greenhouse plant near Voronezh, a cascade of three stages was installed: rough mechanical, then sand and gravel, and at the output - ultraviolet treatment. Expensive, but in two seasons there has not been a single case of emitter clogging.

By the way, aboutintegration of water and fertilizers- here many people sin with excessive automation. I have seen systems where each mixing unit is equipped with an individual controller. In practice, it turns out that it is easier to have a central module for preparing the solution with subsequent distribution to zones. There are fewer points of failure, and the equipment is easier to calibrate.

Real cases and their pitfalls

Last year, we converted a greenhouse near Kaliningrad - switched from soil cultivation to hydroponics. The main mistake of the customer is saving on the disinfection system. Three months later, algae appeared in the pipelines, and we had to urgently install UV sterilizers and change the hoses.

An interesting point with the temperature of the nutrient solution: in winter, when heating the greenhouses with gas burners, the air warmed up to +25°C, and the solution in the containers was +15°C. Plants experienced temperature shock with each watering. We decided to install heat exchangers on the recirculation line - the simplest plate ones, but the effect was noticeable after a week.

I especially want to mention the project withShandong Lingyao Co.,Ltdfor equipping a research greenhouse in the Krasnodar region. There they just used their developments for remote control of valves - not to say that it is ideal, but at least the communication protocol is stable and does not glitch in bad weather like some wireless systems.

Common design mistakes

The most painful area is the calculation of pump performance. They often take it with a margin of 20%, forgetting that with long lines, friction losses can reach 40%. As a result, in distant areas of the greenhouse the pressure drops below the minimum for drippers to operate.

Another point with drainage - in Dutch schemes they usually plan for 30% drainage, but in our case, with high water hardness, it is better to plan 40-45%, otherwise salts begin to accumulate in the substrate within two weeks.

I noticed an interesting pattern: many designers do not take into account seasonal changes in the chemical composition of water. For example, in the spring, during a flood, our iron content sharply increases - without additional iron removal filters, the entire system fails within a month.

Prospects and what really matters

There is a lot of talk now about AI in greenhouse management, but in practice, simple systems with drainage feedback are so far the most effective. You measure the EC and pH of the drain - and based on this data you adjust the supply. No artificial intelligence can predict how a specific batch of fertilizers from a new supplier will behave.

By the way, about the equipment, the reliability of domestic sensors has improved significantly in recent years. Previously, it was necessary to install imported sensors, which failed from the slightest condensation. Now many greenhouse plants are switching to Russian analogues - the accuracy may be a little lower, but the maintainability is higher.

If we talk about trends, I see the most promising direction in modular solutions exactly like those offered byShandong Lingyao— when you can customize a system for specific conditions, and not overpay for unnecessary functions. This is especially important for small greenhouse farms, where every extra square meter counts.

Conclusions that are not written in textbooks

The main lesson from ten years of working with hydroponics is that there are no universal solutions. What works in the Moscow region will fail in the Stavropol region. Each time you have to re-select the parameters, taking into account the water, the climate, and even the varietal characteristics of the plants.

Another important point is the staff. You can install the most modern system, but if the operator does not understand the principles of hydroponics, he will still water 'on a whim'. Therefore, now we always include training in the project - at least two weeks of practice with our technologist.

And yes - never skimp on shut-off valves. It is better to install simple ball valves in each zone than to turn off the entire greenhouse in the event of an accident. This is a truth that has been tested in dozens of emergency situations over the years.