The results are clear – changing the way macadamia trees are farmed could create a win for both the environment and farmers in NSW.

A new study shows a dramatic reduction of soil loss and fertiliser nutrient run-off when farming practices known as integrated orchard management (IOM) are used.

In an Australian first, the research has scientifically measured the water quality benefits of IOM.

Scientists from the NSW Department of Climate Change, Energy, the Environment and Water (DCCEEW) wanted to help reduce the amount of sediment and nutrients ending up in coastal waterways and commissioned a report to measure the effectiveness of IOM techniques on improving water quality.

The water runoff from two side-by-side macadamia orchards were compared.

The first orchard plot was managed with IOM techniques, while the second plot was not.

The study showed the IOM plot had 95 per cent less soil loss, and 70 per cent less fertiliser nutrient run-off, compared to the non-IOM plot.

Cleaner farming practices lead to cleaner water runoff, which in turn leads to cleaner creeks, rivers and coastal environments.

Soil sediment and fertiliser nutrients from farming, such as nitrogen and phosphorus, can pollute creeks and rivers that flow into the ocean, damaging aquatic wildlife and vegetation, and causing algal blooms.

The IOM techniques used in this research strategically reduced the macadamia orchard canopy cover, which increased light to the orchard floor.

More sunlight improves ground cover between trees and when this is combined with improved drainage, there is better water infiltration and less erosion, reducing nutrient and sediment run off.

The innovative IOM techniques were developed by the NSW Department of Primary Industries and Regional Development (DPIRD), in collaboration with the Australian Macadamia Society.

The research was conducted by Southern Cross University (SCU) in coordination with the DPIRD Clean Coastal Catchments research project, and the Richmond River Catchment Partnership.

Australian Macadamia Society industry development manager Leoni Kojetin says grower interest in integrated orchard management has been gaining momentum in the past decade.

“Research like this highlights healthy groundcover and good orchard design and management not only boosts productivity but also protects our environment,” Leoni adds.

Key findings:

• Soil loss was reduced by approximately 95 per cent, and nutrient loss by approximately 70 per cent, compared to the non-IOM plot.

• The research found IOM retains around 7 tonnes more soil per hectare each year when compared to an equivalent macadamia block managed without IOM techniques.

• IOM practices reduced surface water run-off by approximately 70 per cent, promoting greater rainfall infiltration in the orchard.