Times are difficult and Ireland has not escaped unscathed. There will always be those who throw in the towel, but diehard growers face the challenge of reorientation. Compared to other countries the Irish are quick to accept new methods and prepared to switch to alternative cultivation systems. At the moment, due to these rapid changes, Ireland is probably the country with the widest variety of different cultivation systems. All to be visited in the space of a few hours.

The satellite system was first invented in Ireland. Pat Walsh can claim to be the innovator behind its large-scale introduction. The system is quite simple. Compost companies sell compost to an associated group of growers, then buy the mushroom crop back from the growers. Further marketing of the mushrooms is handled by the sales organisation of the compost company. Growers have a secure source of compost and a guaranteed market for their mushrooms.

The growing facilities are all pretty similar and built according to a standard pattern. A typical Irish farm consists of a series of three semi-circular sheds, called tunnels. The set-up includes a pack house per unit where the mushrooms are prepared for transport and a canteen. If new tunnels are added to the facility, the pack house automatically grows with the organisation.

The satellite system in its original form still functions in many cases. In the meantime an umbrella marketing organisation has been founded. Each grower can sell mushrooms via this marketing organisation, called CMP.

The bag system (bags)

In the early days of the satellite system, growing rooms were very basic. A simple, semi-circular construction on a concrete floor. The spawned compost was supplied in plastic bags. Incubation took place in the same growing room.

The great attraction of this system is the low investment in buildings and machinery. The bags are delivered on pallets and the size of the tunnels is the equivalent of a lorry load. As soon as the bags arrive, they are placed in rows. This is usually three blocks of rows with room to walk in between. The centre row numbers four rows of bags, the rows at the sides usually have one or two adjacent rows of bags. The top of the bag is folded over so the bag remains more or less closed. Just prior to casing the bags are cut to just above the compost layer. Casing is done manually, as mechanisation is difficult with this system.

This immediately highlights certain disadvantages of the system. Counter balancing the low investments is the intensive manual labour involved in moving the bags, casing and lifting bags out of the tunnel after cropping.

The block system (blocks)

A logical sequel to the bag system is compost pressed into blocks. The inoculated compost is also supplied on pallets, but now in blocks weighing around 20 kilos. These blocks are easier to handle than bags and they can be used in several layers in the tunnel.

Just like bags, the blocks are removed form the pallets and placed in the tunnel on arrival. The blocks are positioned in the same way as the bags. However, above the row on the floor, a shelf is often built to accommodate a second or even third layer. When the compost is incubated, the plastic covering the top of the block is cut away, resulting in a good, level compost layer. Manual casing is also done here, but the level upper layer makes the process far easier then with bags and casing quality is better.

A disadvantage of the system is that the blocks in contact with the floor are often colder. Nowadays they are often placed on pallets or shelving to raise them slightly above the cold concrete.  Recently a system of bags on the ground with a layer of blocks on so-called staging above has become popular. This system is not surprisingly called “blocks over bags”.

Switching to a system of several compost layers in a growing room demands certain technical modifications. The volume of compost in the growing room is greater, so the ventilation capacity must be adapted accordingly. Installation of an adequate cooling system is essential here.

The bed system (Dutch shelving)

Over the past few years a select group of growers have sought refuge in the bed system. The Irish refer to this as the “Dutch Shelving” system. The standard width of the growing rooms means the beds are 120 centimetres wide. Initially, shelving was placed two tiers high, but larger growers also have rooms with three rows of beds, three or four tiers high. Rooms are also being built according to the semi-circular tunnel principle. These are wider and higher so can comfortably house shelving of 134 centimetres.

The advantages of the shelving system are obvious. Filling and emptying is mechanized, so less labour intensive. More compost can be filled on the same floor surface area and the possibility of incubated compost is open.

But this is the crux of the matter. The availability of incubated compost (phase 3 compost) is very limited. Not all compost companies can supply phase 3 and the demand from growers greatly exceeds the supply. Transport is also problematic. There is a lack of suitable vehicles and the Irish infrastructure often means long delivery times. A trailer for incubated compost can often only fill two or even just one room per day.

This explains why certain growers fill a number of growing rooms with spawned compost and the rest with blocks of inoculated compost or even compost filled on the beds via a head-filling machine from bags. The result is a complicated organisational structure. Growers working with diverse types of compost on one farm have to treat each growing room differently.

Casing the beds is however simple, and there are many good casing machines on the market. This shelving system suits advanced mechanisation so heavier casing soil can be used, with the resulting effect being heavier mushrooms.

An often-overlooked fact when switching to this cultivation method is the increased volume of compost in each room. The necessary adjustments to the climate system must not be forgotten. Plus, the correct machinery must be purchased and on site before the first flushes are started.

Interview with Jimmy Hackett

Jimmy Hackett is a grower from Monaghan. A true veteran at the game of mushroom growing. In 1980 he started as a satellite of the Monaghan group with three growing rooms and a pack house. At the time each growing room housed 1000 bags of compost. After these first steps- taken together with around 60 other budding growers in the area - he added a new growing room nearly every two years.

He now has 12 growing rooms, each of 230 square metres with shelving. Shelving is in two rows, three tiers high. Current production levels reach 14 tons of mushrooms weekly, all destined for the UK export market. He switched straight to shelving, and left out blocks as he considers blocks too labour intensive. The company is currently run in partnership with his wife, who coordinates harvesting. She has recently booked success using the so-called “Graze Picking” method advised by AdVisie. This system means highly selective picking several times a day over the same beds. Not always an easy task but one supervised to perfection by Margaret.

In the future, both their sons plan to take over the farm. They still see a future in the business, if the labour predicament can be solved. Surprisingly there is no shortage of workers at the moment, but the entire cultivation process must be made less labour intensive to keep the cost price in check. In Jimmy's opinion the switch to shelving has made a significant contribution. To quote him: “If I hadn’t started using shelving, I'd no longer be a grower.” The intense heavy manual labour makes growing too expensive otherwise. His future investment plans are therefore focussed on good machinery and optimising the climate installation.

Interview with Martin Doyle

Martin Doyle is the grower for Gold Shield in Kells. He was one of the first growers who switched to beds. Seven years have now passed; at the start he still filled the beds using blocks of inoculated compost. After a brief period using compost imported from Belgium, he now has sufficient supplies of incubated compost from Irish companies.

He's currently very satisfied with the quality of the incubated compost he's using. There's good activity and he can spray water on the compost during filling, if things threaten to become too active.

After exhaustive consultation with Dutch growers and a Dutch advisor he decided to totally revolutionize his cultivation methods. He has the right machinery to cope with very heavy casing soil, which he compacts lightly. He is an advocate of compost cac-ing during filling. He waters the casing soil copiously in the beginning of the growing schedule and reduces the amount of water each day as the mycelium grows in the casing soil.

The biggest change during the cultivation process is use of a far more restrained climate. The lower air speed and slightly higher RH keep evaporation lower so the beds do not dehydrate. This used to be a problem and sometimes caused bacterial blotch.

In reflection, the transitional period had many ups and downs. By winning advice from the right people and regularly attending study groups, he was able to implement the many changes successfully. As he remarks, growing in this way is totally different to in bags or blocks. This different approach took him the most getting accustomed to .

Changes

The Irish mushroom growing sector is experiencing serious upheaval. Partly driven by depressed prices, partly by the necessity of progress. Until quite recently it was customary practice for growers to use the bags which held the compost deliveries. The bags stood in rows on the floor. Now the express wish is to fill incubated compost in growing rooms in larger quantities than were ever possible previously.

In this respect, certain problems confront the Irish. Existing growing rooms are not always spacious enough to house the required square metres of shelving and need to be modified. Machinery is not always available. However, more new machinery is on the market with plenty of good second hand equipment on offer.

Another factor limiting the kilo yield is the capacity of the climate units. There is often a shortfall in capacity after filling the greater compost volume. Change is needed here too. A number of growers have taken a very thorough professional approach, and even changed the picking methods on their farms. One of these shining examples is Jimmy Hackett's enterprise. They successfully introduced graze picking which works really well on the shelving. In fact, sometimes even better than in the Netherlands, as the lower shelving makes logistics simpler.

The only aspect still demanding attention for the future is increasing the production of incubated compost. There is a desperate shortage of incubated compost among companies that have started using the bed shelving system.