MACADAMIA
Smart macadamia irrigation is the key NETAFIM
“Experience in macadamia production indicates the importance of proper soil preparation,” says Chris Malan, manager of agronomy at Netafim South Africa. These actions will result in a larger and healthier root zone that will ensure consistently high production.
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LTHOUGH RESEARCH AND experience suggest that macadamia trees use water quite sparingly when compared to other tree crops, optimal irrigation remains crucial to efficient macadamia nut production. Chris explains that irrigation of macadamia trees is particularly important during flowering, from the time of nut set, during nut filling and the vegetative growth period in mid-summer. "Various irrigation strategies exist and different methods of irrigation can be implemented. Prevailing climatic conditions in combination with factors such as soil depth and fertility, availability of water for irrigation and more will influence the irrigation strategy." Both drip irrigation and micro-sprinkler systems are used in macadamia tree irrigation across Southern Africa. These systems cater for different conditions, preferences and approaches to production. “Macadamia tree irrigation approaches are still being refined as the industry learns more about tree water requirements and how climatic conditions affects it. Approaches range from highly intensive daily irrigation and fertigation to an extensive approach where irrigation events are adapted to the most important phenological growth stages, the climatic conditions and available resources.” Chris emphasises that there is a shift towards increased implementation of drip irrigation as increased focus is placed on water-use efficiency. Efficient water use “We know that there is no one-size-fits-all answer to improved irrigation scheduling on macadamias or any other
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Sources of water loss.
crop. As we aspire toward increased efficiency, various aspects must be kept in mind. When we want to manage water optimally in orchards it is important that we understand water balance in an orchard, soil-water interaction and factors that impact it," explains Chris. "Efficient water use is about preventing water loss on the one hand and ensuring optimal water intake by the roots on the other hand. Water loss can occur through evaporation, deep percolation, subsurface outflow, run-off and transpiration. The latter is the only positive water loss as water moves through the plant. Our aim is, therefore, to maximise tree transpiration while we minimise soil evaporation and water use by vegetation between tree rows."
MARCH • APRIL 2021 | VEGETABLES & FRUIT
