Want optimal irrigation? Don't make assumptions

Plan, execute, control and verify. These are the four elements that constitute the irrigation approach of Indigo Fruit Farming in Mpumalanga, where every drop of water is used to its full potential. Farm manager Willem Kieviet spoke to Lindi Botha about his methods of irrigating to achieve the best crop yields.

“The days of starting the pump in an orchard and assuming the trees will be watered are long gone,” says Willem Kieviet, area manager of Indigo Fruit Farming on the outskirts of Mbombela, Mpumalanga.

Instead, he uses a meticulous method in which every decision is backed up by data, and any water applications are checked and double-checked.

“You need to think about how much water you’re applying and why. Ask yourself what time of the day is best for irrigating and what the expected outcome of the irrigation is, then measure whether it was achieved. Applications that rely on technology must be followed up by people, and vice versa.”

Indigo produces mandarins and seedless lemons, and has been using drip irrigation since 1997. Kieviet prefers this method to micro-irrigation, as it uses less water.

“With micro-irrigation, there’s more evaporation because you’re wetting a bigger surface area. Also, the water penetration isn’t necessarily as deep as with drip irrigation, so you lose a portion of the water you apply. Drip irrigation is more focused on a specific area.”

As the farms have mostly sandy loam soil, drip irrigation provides a further benefit: the drippers provide a suitable flow of water to top up the moisture levels without run-off.