Dramatic Savings With Low-Flow Drip Irrigation

By switching from micro-irrigation to low-flow drip irrigation, macadamia farmer Dawid de Kock has reduced his irrigation water usage by 50%. With the subsequent savings on electricity, fertiliser and labour, the system has significantly improved his bottom line.

- Lindi Botha

A farm’s irrigation system affects many factors that in turn determine profitability. The efficacy and efficiency of labour, electricity, water and fertiliser are all influenced by the type of irrigation system and the way it is managed.

With this in mind, Dawid de Kock, a macadamia farmer in Mbombela, Mpumalanga, has implemented a low-flow drip irrigation system on his newly established orchards. His older orchards all have micro-irrigation.

“The Netafim TurboNet low-flow drip irrigation system delivers water at the same rate at which the plant absorbs it. This ensures that the soil moisture is at the optimal level and the tree doesn’t drown or dry out. This also ensures that there’s no run-off, evaporation or leaching of the soil,” he says.

De Kock has 140ha of mature trees under micro-irrigation, which will soon be converted to low-flow drip irrigation. The newly planted orchard under low-flow drip irrigation has 68ha of two-year-old macadamia trees.

IMPLEMENTING THE SYSTEM

Netafim’s newly developed TurboNet flow path technology allows for low water delivery rates, delivering 1/h or less per dripper. The system saves water by irrigating only in the active root zone.

To achieve optimal aeration conditions, drippers are spaced so that the perimeters of the wetted areas under adjacent drippers are about 1m apart. Generally, one dripper is placed on every 2m² of canopy area of mature trees.

De Kock has a double row of irrigation pipes alongside the trees. His orchards are planted at a spacing of 8m x 5m, resulting in a density of 350 trees/ha. This requires 10 drippers per tree, so that each tree is irrigated at a rate of 10/ h. Irrigation volume depends on the size of the trees and the moisture levels in the soil, as determined by the tensiometer. He irrigates the two-year-old trees for about five hours a day during spring.