In every case we make sure we know the optimum amount of water each square foot needs to grow, and our quality assurance process ensures the supply of a more consistent product. We don’t take water from the Murray river: surplus capacity of high quality aquifer water in the Mallee plus access to recycled and bore water in Virginia allows for increased production as markets dictate.
Mallee Aquifer Water
Mallee water quality has not changed in 20 years of pumping, and is tested annually. Zerella Fresh is fortunate to be located on the epicentre of the best water quality in the Mallee prescribed wells at Parilla. The Mallee Prescribed Wells Area (MPWA) of South Australia covers some 8000km2. It is estimated that within the MPWA, the Murray Group Limestone aquifer contains some 100 million megalitres of groundwater. Under the current extraction regime, the aquifer will be depleted by some 15% after 300 years if pumping were to occur at the maximum rate. This compares very favourably to taking water from the River Murray, which is dependent upon seasonal flows and subject to overextraction.
Bolívar Recycled Water
Our Virginia growing region utilises treated water from the local Bolivar treatment facility, significantly reducing pressure on the local aquifer. SA Water treats about 95,000 ML of wastewater each year at its four Waste Water Treatment Plants at Bolivar, Port Adelaide, Glenelg and Christies Beach. The Bolivar plant treats about 46,000 ML wastewater annually, and has resulted in high quality treated wastewater being piped to growers on the Northern Adelaide Plains through the Virginia Pipeline Scheme.
These plants play a key role in reducing the amount of wastewater entering the Gulf of St Vincent and to recycle high quality treated wastewater for irrigation purposes. The Virginia Pipeline Scheme is the first and largest recycled water scheme in Australia serving around 250 horticultural growers including Zerella Fresh.
Variable Rate Irrigation and Soil Science
Prior to planting, sites are mapped for contours, soil variation and intended plantings. Variable rate irrigators are then utilised to ensure the optimal amount of water is delivered to each plant. This efficient large scale watering technique is customised for the different soils, contours and crops; saving water, energy, fertiliser and other inputs, making it the ideal environmental solution too.
Disease and Pest Avoidance
Our continued investment in fresh land combined with long crop rotations minimises disease and pest pressure and the consequential use of unnecessary inputs.
Composting and Green Manure Cropping
We utilise our own generated waste including onion shells and unsaleable product combined with other waste generated in the region to produce compost. This includes almond hulls, sawdust, woodchips, straw and animal manure. This fully composted treasure is spread over sites with benefits including utilisation of waste, improved soil qualities leading to greater yield and disease resistance, plus better water holding capacity of the soil.
Green manure crops are grown on a rotational basis and ploughed back into the soil prior to planting.
Post Harvest Wash Water
Potatoes and carrots are washed using purified recycled water drawn from a wetland which captures local storm water.