The macadamia tree, Macadamia integrifolia, is considered an ‘ecological giant’ in commercial agriculture in the horticultural sector. This may be ascribed to its efficiency to optimise water consumption, sequester carbon from the atmosphere, absorb phosphates and recycle organic waste material.
Macadamias are not heavy-feeders and the fine lateral feeder roots have the ability to absorb phosphates and calcium from soils, even in low concentrations. There is scope, therefore, for more ecologically friendly fertiliser applications.
Preliminary research findings indicate the average macadamia orchard absorbs more than 17 tonnes gross, and 14.5 tonnes net, of carbon per hectare per year from the atmosphere.
his could lead to a reduction in the application of high dosages of fertiliser, excessive irrigation, and carbon dioxide emissions.
The demand for, and export of, macadamia nuts has increased significantly for South African growers over the past ten years. However, the quality of nuts, crackout percentages, yield and overall performance of trees, have not been altogether satisfactory. Since good soil health is fundamental to productive agriculture and may play a role in the long-term sustainability of macadamia orchards, scientists are studying various aspects of the soil in these orchards.