How We Irrigate Our Chilli Fields at Magical Micro Farm

Water is one of the most important resources on any farm, but simply putting more water onto a field doesn't necessarily mean healthier plants.

At Magical Micro Farm, we grow our chillies using a gravity-fed drip irrigation system designed to put water where we actually need it: at the roots of the plants.

Our system has evolved as the farm has grown. Today it consists of six independently controlled 20 × 20 metre growing blocks supplied from an elevated water tank through a 50 mm mainline.

There is no pressure pump between the tank and the fields. Gravity does the work.

Here's how the whole system fits together.

The farm is divided into six irrigation blocks

Our main growing area consists of six blocks, each measuring approximately 20 × 20 metres.

That gives us:

• 400 m² per block
• 2,400 m² across all six blocks

Dividing the farm into separate irrigation zones gives us much more control than treating the entire field as one large irrigation area.

Each block has its own valve, so we can irrigate one block, several blocks, or shut a block off completely when necessary.

This becomes particularly useful when different blocks contain plants at different stages of development.

30 cm drip spacing along every row

Each growing row is approximately 20 metres long and has its own drip line.

The emitters are spaced at 30 cm intervals, with each emitter rated at approximately 1.1 litres per hour.

That works out to roughly:

• 20 m ÷ 0.30 m = 67 emitters per row
• 67 × 1.1 = approximately 74 litres per hour per row

Our blocks contain approximately 13 drip rows, giving us roughly 870 individual drip points in a single block.

The theoretical flow for an entire block is therefore:

• 870 × 1.1 L/hour = approximately 957 L/hour

For practical purposes, we call it roughly 1,000 litres per hour per block.

It's worth pointing out that this is the theoretical rated flow. Actual emitter output can vary according to the pressure available in the system.

Because ours is gravity fed, that's something we're particularly interested in measuring and monitoring.

Why drip irrigation?

For us, drip irrigation makes sense because we're not trying to water 400 m² of soil uniformly.

We're trying to water the root zones of the plants growing in that 400 m².

Instead of spraying water into the air and wetting pathways and other areas where we're not growing anything, drip irrigation concentrates water along the planted rows.

It also keeps much of the plant foliage dry during normal irrigation.

And on a farm where thousands of plants need water, small efficiencies quickly become big ones.

From 13 drip lines into one 32 mm supply

The individual drip lines don't run all the way back to the water tank.

Instead, each block has a 32 mm supply pipe running along it.

All the drip lines in that block connect to the 32 mm pipe.

That 32 mm supply has its own valve where it connects to the farm's main irrigation network.

This gives us six valves in total, one for each growing block.

Open the valve and the entire block receives water. Close it and that block is isolated.

Simple, but extremely useful.

The 50 mm backbone of the system

All six 32 mm block supplies eventually connect to a much larger 50 mm mainline.

Think of the 50 mm pipe as the irrigation system's backbone.

Instead of trying to push the combined water requirement of several blocks through a small pipe over a relatively long distance, the 50 mm main carries the bulk water down the farm.

Only when the water reaches an individual block does it branch into the smaller 32 mm supply.

At the theoretical emitter flow rates, the system requires approximately:

• 1 block: 960 L/hour
• 2 blocks: 1,920 L/hour
• 3 blocks: 2,870 L/hour
• 4 blocks: 3,830 L/hour
• 6 blocks: 5,740 L/hour

Three blocks at a time

During previous seasons we've successfully operated four blocks simultaneously when the water tank was full and the borehole was replenishing it.

But just because something can work doesn't necessarily mean that's the best way to operate it.

This season we're planning to divide the field into two irrigation groups:

• Blocks 1, 2 and 3
• followed by Blocks 4, 5 and 6

Three blocks require a theoretical flow of roughly 2,870 litres per hour.

Running fewer blocks simultaneously should give us more pressure in reserve and help maintain more consistent flow through the drip lines, particularly toward the furthest parts of the irrigation network.

And there is no irrigation pressure pump

This is probably one of the more interesting parts of our system.

The borehole does have a pump, but that pump's job is to put water into our storage tank.

The irrigation network itself isn't directly pressurised by a pump.

Our tank is elevated, with the bottom of the tank approximately 10 metres above the irrigation system.

Water pressure from elevation can be expressed as metres of head, with approximately:

• 10 metres of water head ≈ 1 bar

So gravity provides the pressure needed to move water from the tank, through the 50 mm mainline, into the 32 mm block supplies and eventually through hundreds of small drip emitters.

When the tank is full, the actual water level is higher than the bottom of the tank, giving us some additional head pressure.

It is a relatively simple system, and that's part of what we like about it.

Turning irrigation into fertigation

We're also adding another component to the system this season: a Venturi fertiliser injector.

Instead of manually carrying liquid feed around the farm and drenching thousands of plants individually, the idea is to introduce suitable liquid nutrients directly into the irrigation water.

This is known as fertigation.

We're installing a single Venturi station on the 50 mm mainline near the greenhouse, before the irrigation water reaches the six individual blocks.

That means we don't need six separate fertiliser injectors. The same central injector can service whichever blocks we choose to open.

If Blocks 1, 2 and 3 are open, they can receive the fertigation treatment. Once they're finished, we can close those valves and move on to Blocks 4, 5 and 6.

How does a Venturi work without another pump?

A Venturi uses a restriction in flowing water to create a pressure difference.

That pressure difference creates suction, allowing a concentrated nutrient solution to be drawn into the irrigation water.

Our planned installation uses the Venturi on a bypass around the 50 mm mainline, rather than restricting the entire farm's water supply through a small Venturi.

Because our irrigation is gravity fed and operates at relatively low pressure, choosing and calibrating the injector correctly is important.

Once installed, we'll measure its actual suction rate rather than simply relying on the number printed on the packaging.

That's farming in a nutshell: measure what actually happens in your field.

How much water are we actually applying?

Knowing the flow rate also lets us translate irrigation time into something more useful.

A 20 × 20 m block has an area of 400 m².

One millimetre of water over one square metre equals one litre. Therefore:

• 1 mm of irrigation over one block = 400 litres
• If our block is receiving approximately 960 to 1,000 L/hour, one hour of irrigation represents roughly 2.4 to 2.5 mm of water
• Two hours would theoretically apply approximately 4.8 to 5 mm

That gives us a much better way to manage irrigation. Rather than saying "we always irrigate for two hours", we can consider how much water the plants actually need based on their growth stage, weather, rainfall and soil conditions.

That's particularly important in Potchefstroom, where conditions can change dramatically through the growing season.

Why all of this matters to the chillies we sell

The irrigation pipes themselves aren't particularly glamorous.

Nobody opens a bottle of chilli sauce and thinks about a 50 mm irrigation main.

But for us, this is where the finished product actually starts.

The chillies we harvest need to be grown first. That means germinating the seed, raising the seedlings, preparing the soil, transplanting, irrigating, feeding, managing pests and diseases, and eventually harvesting ripe fruit.

Only then can we start turning those chillies into the products that leave Magical Micro Farm.

When we say from seed to sauce, we mean it quite literally.

If you'd like to taste the other end of this process, you can explore the products currently available from our farm in the Magical Micro Farm online shop.

Shop Magical Micro Farm

From our handcrafted chilli products to seasonal releases, your order helps us keep doing what you've just read about: growing the crop, improving the farm and producing something we're proud to put our name on.

Follow the 2026/27 growing season

We'll be sharing much more of the new season as it develops, including germination, greenhouse progress, transplanting, irrigation, fertigation, field management and eventually the harvest.

And we'll also be sharing the things that don't work.

Because farming isn't a perfectly polished process. Every season teaches us something new, and we're continually changing the way we grow based on what we see happening in our own fields.

If you'd like to see the irrigation system rather than just read about it, watch our latest YouTube video where we walk through the actual system on the farm.

From the tank, to the mainline, to the dripper, to the plant.

And eventually, from the plant to the bottle. 🌱🌶️