Light on stock numbers, last spring Jonathon and Julie Bennett and the monitor farm community group decided to generate some cash by growing 16ha of whole crop barley silage.
They believed they had it sold to a dairy farmer, but Mr Bennett said no contract was entered into, which was a mistake.
Potentially, the crop would have returned $28,800, or 18c a kg of dry matter.
When it came to harvesting, the financial situation for dairying had deteriorated and the dairy farmer said he no longer wanted it.
No other dairy farmer was interested and the Bennetts harvested it for their own use.
It yielded 10 tonnes a hectare and harvesting cost them an extra 6c a kg of dry matter for a total cost of 17c a kg of dry matter.
Monitor farm convener Simon Glennie, from Abacus Bio, said with hindsight they should have had a written contract, but he knew of other dairy farmers walking away from contracts.
Mr Bennett said he felt let down by the dairy farmer, but admitted he should have had a back-up plan, especially what animals could eat the feed.
Test have shown the crop to be of ruffage quality and low in energy.
It would be used in conjunction with other feed.
Mr Glennie said growing extra grass by using nitrogen was competitive with the cost of the whole crop silage.