To begin, a look at the mushroom output spanning this period:

Year    Total MushProduction (tonnes)   Est exported UK

1971            3,110                                                 50% 

2014            69,635                                               75%

In Ireland,mushroom production in the 1970s was on the wooden tray system. There were 6 to 7 large farms with over 100,000 sq.ft bed area and 20 smaller farms. The large farms produced their own compost from wheaten straw, poultry litter and horse manure when available. Peak heat was achieved by steam in specialised houses in the wooden trays. The trays were transported by forklift to a spawning machine and were then stacked in the growing houses.  The capital investment to do both the composting and growing was huge and limited any access for new growers to the industry. 

Dutch Industry:

By contrast the Dutch Industry was based on fixed steel shelving rather than mobile trays.  Centralised compost farms produced and delivered Phase 1 compost to the mushroom growing farms.  The compost was filled onto the shelves by elevators then peak heated, spawned and grown in the same houses.  These growing farms with fixed shelving and machinery,and in-house peak heat involved very large capital investment.

Mobile Compost in Ireland:Most of the smaller growers in Ireland were supplied with Phase 1 compost. An example of compost for supply was in the mid 70s, Dudgeons in Monaghan a large tray grower, was selling 300 to 400t per week to the small tray growers in the Monaghan area.

Peak Heat on the Small Farms:This Phase 1 was trucked to the farms and filled into wooden trays and peak heated.  The peak heat facilities were limited to hot water pipes and boosted by burning coke in barrels.  The Phase 2 pasteurisation was variable.

Developments:There was research in the 1970s into new developments,which would take the mushroom industry in Ireland to the next stage.