CONTINUAL cropping in a district with an average rainfall of 250 millimetres is a tough ask but Don and Carolin Rankin, Pendrea, Werrimull, Vic, have developed a unique way to maintain yields.
Since 2010 they have used Australian Vermiculture products instead of DAP fertiliser, producing the same yields for a fraction of their regular price.
"Several years ago we were paying $1600 a tonne to lock-in fertiliser prices and they were saying that we may have to pay up to $2000/t," Don said.
"At the time being in a drought with yields of 0.6t a hectare, it wasn't feasible.
"So we decided to run a trial with 2000 litres of Progrow liquid."
Progrow liquid was foliar applied to Gladius wheat at a rate of 6 litres/ha in a water rate of 80L/ha.
The concentration of nitrogen, phosphorus and sulphur for each hectare was equivalent to 7.8-9.6u/ha (N), 0.96-1.2u/ha (P) and 6.608u/ha (S).
The Rankins saw a "significant" response to the application.
"Within 72 hours the colour of the plant was enhanced to a deep, lush green," Don said.
"Within two weeks the foliage had greatly improved, adding more tillers."
The Progrow liquid is used alongside an organic carbon powder coated on seed at a rate of 5 kilograms/t and an organic liquid phosphorus seed coating at 5L/t.
Four to six weeks after sowing, Progrow is applied at 5L/ha and zinc sulphate at 2L/ha with any broadleaf sprays.
"We've gone from spending $150,000 a year for fertiliser to $24,000," Don said.
"The difference we use as profit - we're $130,000 better off than we were."
When fertiliser prices were high, Don researched potential alternatives.
"I went to carbon conferences and all that," he said.
But talking to local agronomist and friend Jayson 'Butch' Butcher, who works with AV's Del and Brendan Price, Mildura, Don found a solution relatively close to home.
"We're spending much less money for the same result," he said.
"Crops are yielding the same for a fifth of the cost.
"We're averaging the same - about 1.2-1.6t/ha - to a bit above what we were previously."
Protein in wheat crops has also improved since using AV products, up 0.5-1 per cent.
"The soil pH has also dropped from 7.8-8 to 6.6-7 in some spots," Don said.
"The more saline areas are also producing better crops."
Don said plants grew differently since using AV products, putting most of their energy into reproductive systems."
* Full report in Stock Journal, September 11, 2014 issue.