Managing multiple citrus crops on predominantly high pH soils near Nangiloc in the Sunraysia region requires ongoing monitoring, adjusted nutrient strategies, and the use of analytical tools to support production decisions. Southern Cross Farms manages Imperial and Afourer mandarins, as well as navel oranges, grapefruit, and lemons, across about 200 hectares in the area.
The tree age on the property ranges from five to 30 years. Fruit is sent to a local packhouse in Mildura. According to orchard manager Danny Turner, management practices have evolved to support a more integrated approach to tree health and yield consistency.
The property consists mainly of loamy and limestone soils, with sections of river flats and heavier ground. Soil testing is carried out regularly and has shown a strong requirement for iron in the high pH soils. Leaf analysis is also collected each March to guide nutrient planning for the following season. Recent results again indicated low zinc and manganese levels, with corrective applications scheduled for December.
Turner said albedo breakdown was observed during a recent season, leading to increased use of calcium to support rind strength. Irrigation infrastructure has been upgraded from overhead sprinklers to full drip irrigation. The system draws water from the Murray River and is controlled via a MAIT Industries platform, allowing fertigation of nutrients such as zinc and manganese while reducing nutrient losses.
The property also uses mapping technology two to three times per season. Data such as NDVI and chlorophyll readings are used to assess tree health, canopy development, and fruit sizing. Fertigation follows a monthly nitrogen, phosphorus, and potassium program, with weekly applications, alongside in-season inputs of zinc, manganese, and iron.
"A little bit often is the go. We use a lot of Haifa Multi-K, MKP, and MAP, and the use of Haifa's zinc, manganese, and iron through the drip has been great," Turner said.
"You are always chasing the perfect ratio. In an ideal scenario, if we can hit the sweet spot, we will have 70 per cent plus fruit in first grade."
Foliar potassium applications are also used to support fruit sizing, particularly in mandarins, which Turner said have higher water and nutrient requirements than navel trees. Additional fertilisers are applied to support recovery from stress events, and the farm is increasing its use of biological inputs, including seaweed-based products. For wetter parts of the property, controlled-release fertiliser is being considered for on-farm trials to assess nutrient management options.
Source: Shepparton News
