Jeff McSpedden owns and operates a mixed farming enterprise, Spring Field Farm, on the outskirts of Bathurst, New South Wales.
The commercial operation, which has been supplying vegetables to Simplot for 50 years, has “a strong focus on” vegetables, along with cropping and livestock.

In the past, McSpedden has applied biosolids to his soils. Due to recent health regulations and current best practice, however, biosolids can no longer be used.
“Next gen composts are a great step forward,” he says. I am really pleased with the yield results but also with the longer term improvements in soil structure and general sustainability. I see this as a big part of the future."

The compost application

The high-grade NextGen compost blend McSpedden applied to his corn crop last year was sourced from a local supplier, Australian Native Landscapes (ANL), based in Blayney NSW.

ANL, Australia’s largest compost manufacturer, specialises in composts, composted mulches and special 'next gen' blends for agricultural and horticultural cropping systems. All its composting facilities are covered by ANL’s quality assurance programs, which include both NASAA and Australian Standard product certification. ANL also offers ‘supply and spread’ services using either small-scale vineyard spreaders or 30-tonne agricultural spreaders.

“The compost supplied by ANL is of high quality and complies with the current Australian Standard [for Soil Conditioners, Composts and Mulches],” notes Peter Conasch, Senior Land Services Officer (Mixed Farming Systems) for Greater Sydney Local Land Services.

McSpedden applied the NextGen compost mix in place of biosolids to soils in three experimental plots on his property, at different levels of concentration:

• 25 tonnes per hectare;
• 15 tonnes/hectare; and
• 10 tonnes/hectare.

The rest of the paddock was planted without compost as a ‘control’. All four plots were then used to grow a recent commercial corn crop for Simplot.

Key findings

Improved soil structure

After the application of ANL’s high-grade compost mix, McSpedden noted improvements in the soil structure, especially “on poorer country”.

Improved yields, especially at high compost concentration

Varying yields were recorded for the three trial plots and the control.

• The plot to which recycled-organics compost was applied at a rate of 25t/ha yielded 26t/ha of sweet corn.
• The plot to which RO compost was applied at a rate of 15t/ha yielded 20t/ha of sweet corn, as did the plot with compost at a concentration of 10t/ha.
• The rest of the paddock (the control plot) yielded just 18t/ha of sweet corn.

This amounts to around a 10 percent boost in yield after applying compost at rates of 10-15 tonnes per hectare, and a yield increase of more than 40 percent after compost application at 25t/ha.

“Compost – it does work and has a place in farming,” asserts McSpedden. He said that volumes of supply and transport costs were likely to be factors in the economics moving forward.

"For this to be routine practice in my industry we need to be able to rely on supply at predictable and affordable price points", he said.

Next Gen Compost project participant and commercial vegetable grower Jeff McSpedden with Greater Sydney LLS's Matt Plunkett and University of Queensland's Dr Jitka Kochanek at McSpedden's farm near Bathurst, NSW.