The ACCC conducted an inquiry into fertiliser prices within its work on grocery prices at the request of the Government, and Assistant Treasurer, Chris Bowen, has all but endorsed the ACCC's report when he released it last week.

The findings do nothing to ease the angst of farmers adjusting to the news of another price hike in some standard lines of fertiliser, with urea set to rise by $130 a tonne today, along with rises in potash between $130/t and $365/t.

The price now for urea is around the $960/t mark.

And the ACCC findings are at odds with evidence which continues to be gathered and heard by a parliamentary Senate inquiry into the factors behind the price rises.

The inquiry, being led by NSW Liberal Senator Bill Heffernan, has exposed specific cases of market manipulation, market abuses because of too few players in the market and the export of Australian fertiliser to countries such as Brazil, which has exacerbated the domestic supply shortage.

The ACCC said in its report that significant rises in fertiliser prices in Australia were mainly attributable to rapidly increasing global fertiliser prices.

It said these prices were caused by the big increase in world demand for fertilisers due to the expansion in agricultural production, particularly in grain for food, livestock feed and bio-fuels.

It also blamed rises in costs of production associated with the increasing cost of energy.

The report by the ACCC has enraged Senator Heffernan, who declared the commission "as useless as tits on a bull" in this case.

"The ACCC is sadly but predictably a basket of hot air with no forensic power within it," Senator Heffernan said.

"The Senate Committee examining this has found some startling evidence which puts us at odds with the ACCC.

"Part of the problem with the fertiliser market is the high degree of market consolidation, which was ticked off by the ACCC.

"Consequently it is unlikely the ACCC would be critical of its own decision, which is causing part of this problem."

Senator Heffernan said the ACCC had been asked to provide the committee with evidence, which could be as soon as September 19 when it convenes again for more hearings in Canberra.

"Despite what the ACCC says about fertiliser prices, Australian farmers are not stupid and the ACCC just looks as useless as tits on a bull in this instance," he said.

"This is an obvious example of a bureaucratic process which has taken no notice of field evidence."

A spokesman from Mr Bowen's office said the minister was quite satisfied with the ACCC report because it had looked at all the factors and considered submissions from various players within the industry.

He said though that Mr Bowen would also consider whatever findings are made by the Senate Committee, but wouldn't comment on evidence put before that inquiry so far.