Howe Farming: Avocados

Location and design

This trial is in collaboration with Howe Farming, on their avocado farm between Cairns and Mareeba. The climate is sub-tropical, and the soils are Ferrosols supplied with irrigation water from the Mareeba-Dimbulah Scheme.

The trial was established in May-June 2025 and will run until at least March 2028.

The trial has three treatments:

• Control without basalt or lime

• Limestone (1 tonne per hectare in 2025)

• Basalt (40  tonnes per hectare in 2025)

Monitoring

• Fruit yield and quality will be measured every year.
• Leaching of water and solutes will be measured during the wet season, using ‘drainage flux meters’ installed at 0.9 metre depth.

• Surface runoff of water, solutes and sediment will be measured during the wet season, using flumes installed at the downslope end of 9 plots.

• Soil properties will be measured once per year, using soil cores.
• Soil carbon dioxide concentration will be measured continuously.