"It's the harvest that will be the bottleneck - the storage and handling post-harvest.''
Mr Dennison knows of established cropping farmers being offered the lease of pastoral land for cropping, but it is not an option for him, as he is surrounded by dairy farmers also enjoying record returns.
"It is the most economical option and very prudent to lease to an experienced grower, as it gives the grower better utilisation of plant.''
The industry's viability was largely controlled by economies of scale, with land the most expensive element.
Mr Dennison said growing crops was more technically demanding than it was 20 years ago, and with farmers today tending to specialise more, there was a gap in their knowledge.
Growers cannot work to a prescribed formula - crops required monitoring and applying inputs prudently, at the right time. But the lure of high cereal prices was compelling.
"It's been a perfect storm,'' he said.
Peas that a year ago were selling for $600 a tonne were this year selling under contract for $1000 a tonne, ryegrass a year ago made $1.80 to $1.90 a kg while this year $2.50 a kg, feed wheat has risen from $305 to $520 a tonne and barley from $270 to $460.
The market has been volatile, with wheat prices shifting $50 in two days this season.
"What might seem a good price on Monday can be shoddy on Friday. We're not used to this; we're used to the price moving $50 in a season.''
Such is the international interest there is a waiting list of up to a year for machinery such as harvesters, ploughs and grain-handling equipment.
While prices have soared in the last year on the back of growing international prices and land-use changes, Mr Dennison said not all growers had enjoyed the improved returns, as they had forward-sold their crops under contract.
Most were wiser this year but would watch the northern hemisphere harvest in July-August as a guide to how international prices would react. A bumper northern harvest could see prices settle, but a poor harvest could send grain prices soaring again.
"The last quarter of this year is going to be a very interesting time,'' he said.
The United Kingdom has provided a guide, with wheat prices doubling in the last year.
Mr Dennison said growers were reluctant to sign contracts for the coming season because they were disadvantaged last year, and he planned to sow more non-contracted crops and more grass seed.
Grass-seed plantings in the US last year were down 25% on the previous year as farmers grew more wheat and corn, so he was watching the market with interest.
He plans to install more crop storage facilities to give him flexibility, but will sow the same area of cereal on his 350ha farm.