AT the centre of Stu and James Gall's high-tech cropping program on their 6500-hectare Moree property "Tycannah" is an old-tech ingredient: compost.
The Galls began making their own compost after the 2008 fertiliser price spike. It is now at the core of their biological farming program, and a constant source of education about soil fertility and resource use.
When they decided to look for alternative sources of fertiliser, the Galls trialled conventional fertilisers against guano, and compost enriched with nutrients like rock phosphate.
"Early on it looked like the chemical fertilisers were working best," Stu Gall said, "but as the season toughened up, the slower release biological fertiliser kicked in and gave us a yield increase."
Over three years of trials, the biological alternatives delivered up to a 20 per cent better yield in hard seasons.
"That was it for me. It's the tough years when we really have to make money."
Cheap inputs are the key to broadacre composting, as they are to broadacre farming in general.
For base material, the Galls grow their own forage, or buy in cotton trash or weather-damaged hay.
Most of the phosphate and calcium for their cropping program is applied mixed in with the compost, to ensure it is in optimum plant-available form.
Finding new sources of cost-effective nutrient was their biggest challenge. Their composts have included soft-rock phosphate, guano and basalt dust for P; for calcium, they discovered that gypsum-based house wall offcuts break down well under the compost turner's thrashing, although it's a limited source.
Compost can be fussy and time-consuming, which is why the Galls are halting their own production of 1500-1800 tonnes of compost a year, made with neighbour Dave Partridge, and are looking for a contractor to do the job for them. But they aren't going back to out-of-the-bag solutions.
Soils that softened 15 years ago under no-till, cutting fuel costs and machine wear, have softened further. Crop residues break down faster. Crops hang on longer when it dries out, and lodge less in the wet times.
"I'm hoping we can get to the stage where we do everything 100 per cent biological - that our soils are healthy enough that compost is all we need," Mr Gall said.
"The only reason that James and I are here is because the generations in front of us looked after the land. We've tried to do the same thing. It's about managing costs as well as longevity."
Read more about the Galls' operation in The Land feature 10 Of Our Best, out this Thursday.