Buying an irrigation system; from drip irrigation to ebb-flow

An irrigation system for large-scale cultivation in, for example, Africa or South America? The Hortus Supplies International team works with growers on designing and implementing irrigation and fertigation systems across the world. We talk to irrigation specialist Jack van Winden about the various steps, and discuss a number of crucial considerations for new and experiences growers.

Hortus Supplies International consults and supplies to growers across the world. Obviously, one of our specialties is water, crop fertigation. Our experts work on new installations with growers in Africa, North America, South America, and Europe. They are responsible for the entire process from design to implementation and commissioning. We talk to Jack van Winden about the sequence of this process, and about the differences between new and experienced growers.

Crop water and nutrition needs

Growers contact HSI with a clear issue: this is my plot, and I want to use it to grow a particular crop. Together, we determine the water needs, with the grower profiting from our extensive knowledge and experience built up over many years. Eventually, we make a decision based on an apparently simple unit: the amount of water in litres per day required by the plant in this climate and situation.

Effects of foundation on irrigation systems

Next, we discuss the foundation. This factor determines, for example, how water behaves once it is sprinkled on the surface. Water distribution through clay is better than through sand, for example, and requires fewer dropping points.

Irrigation system cost-related choices

In the more familiar grower nations, a large part of the operations in a greenhouse are automated; in Africa and South America, lower wage costs tend to result in less automation. In these cases, we offer our recommendations to the grower with regard to a number of fundamental decisions that have a substantial impact on the irrigation system, but which all boil down to: how, and how quickly, do you want to water the crop?

“We make sure to clearly establish a completion time for the watering process. Does the grower want automated irrigation or irrigation in manned shifts? Or should the process take place during business hours, between 7 am and 5 pm? In essence, this means weighing-up the labour costs against the investment and operational costs of the irrigation system. Naturally, this calculation uses different figures in Africa than it would in Eastern Europe. Based on our experience, we help the grower make the best long-term decision.”

Irrigation system design

Once all of the aforementioned is clear, our specialists head to the drawing board. We use elevation maps to design the complete technical system, and calculate the effects of the decisions from tap to crop. This way, we verify that our suggested solution fully meets the client’s needs 100%.

Irrigation system consultancy

Our experience sometimes also leads us to offer unusual solutions for growers in less technologically advanced areas:

“Whereas many installation companies stop at units that can pump 150 cubic metres per second, we have no problem offering installations that can handle up to 1,000 cubic metres per hour. Others would probably use up to 8 mixing groups, each with their own gauges, computer systems, and required maintenance. If you ask me, that means having too many potential bottlenecks. We prefer using a single, large-scale central pumping system with a fertiliser dosing and regulation system operated from a central silo. This lets us keep things simple, as it means there are much fewer things that can break. And that means there is less for the grower to worry about, as well.”

Investment, efficiency, and power consumption of greenhouse irrigation systems

In Europe and North America, and certainly in the Netherlands, it goes without saying that an irrigation system’s power consumption and efficiency are crucial. But in other areas of the world, power or labour may be so cheap as to lead to different decision-making – which is generally not ideal:

“In many projects, a new grower tends mainly to focus on reducing project investments. They will choose the pump that can move the amount of water to the crop at the lowest price, with little regard for efficiency. Whereas in a country such as Kenia – where power is relatively expensive at roughly 20 cents per kWh – the investment can be earned back in a relatively short period of time with a slightly larger investment in a more efficient pump and larger pipes. Even in Ethiopia – where power is 3 cents per kWh – there is, of course, power prices are not guaranteed. You might even lose power and be forced to run your farm on a generator at 25 cents per kWh for three days. This is why experienced growers in Ethiopia prefer to choose the more sustainable installation to ensure them of a good long-term investment.”

Partnering with experienced growers

The examples and approach detailed above mainly apply for growers looking to open a new farm, or start on a new crop/at a new location. But there are also growers with many years of experience, using one or even several different irrigation systems. These growers have preferences or very specific requirements. How does HSI handle those?

“We sit them down at the table for an in-depth discussion. Experienced growers can explain exactly what was great about the previous system, as well as what changes they would prefer in the next one. We update them on recent developments, and on the potential of those developments for their specific growing needs. You might see a grower who has been using drip irrigation for many years interested in switching to an ebb-flow system – in which case, we explain exactly what they should take into account.

Another grower may be looking for a large expansion in a couple of years. We can take this information into account from the start to make sure that their utility fees do not suddenly spike several years down the line.”

Read more:

Irrigation systems: from consultancy to global delivery