Design Methods for Mushroom Houses and Mushroom Beds in Mushroom Cultivation

1. Mushroom house Mushrooms can be cultivated using old houses, basements, air-raid shelters, rammed-earth cultivation rooms, plastic film houses, and mushroom sheds in sugarcane fields. However, the cultivation mushroom house should meet the following requirements:

(1) The mushroom house should face south, which is conducive to ventilation and indoor insulation in winter. 

(2) The mushroom house structure should be solid, with no air leaks in the roof and walls, and good heat and moisture retention. The surrounding walls and ceiling should be whitewashed with limewater to eliminate pests and prevent contaminating fungi.

(3) The mushroom house should be tightly enclosed; after the doors and windows are closed, no light should pass through, making it a dark room, and there should be no rat holes, so pests cannot easily enter.

(4) Air should circulate. When the doors and windows are opened for ventilation, fresh air can be introduced in a short time and harmful gases can be discharged, without causing drastic changes in indoor temperature. It is best to install fixed ventilation windows; upper windows on the walls, and ground windows at the base of the walls. The lower the ground windows, the better the ventilation. Because carbon dioxide is heavier than air, it often accumulates in the lower layers, and if the ground windows are too high, it is difficult to discharge it. The accumulated concentration of carbon dioxide in the mushroom house should not exceed 0.5%.

(5) It should be close to a clean water source, with an open surrounding area, sufficient space for composting cultivation materials, a relatively high terrain to facilitate drainage, and no factories producing toxic gases nearby.

The structural forms of mushroom houses mainly include the following three types:

① Aboveground mushroom house  This is currently the most common form for cultivating mushrooms, and most are converted from old houses. It has the advantages of good ventilation, convenient operation, and reduced production costs, but without heating and cooling equipment, mushrooms can only be cultivated in spring and autumn.  The aboveground mushroom houses commonly used in the suburbs of Shanghai have a row of ventilation tubes installed on the roof ridge, positioned above the walkway. The upper windows are slightly lower than the eaves, and the ground windows are 8-10 cm above the ground, with a window width of 40 cm and height of 46 cm. The door is the same width as the walkway, with a height sufficient for a person to pass through, and a small window should also be set in the door. Generally, a mushroom house with four rows of bed frames should have two doors.

② Semi-underground mushroom house  Half exposed above ground and half buried underground. During construction, first dig a pit 22 m deep and about 27 m wide, with any length. The four walls are built with bricks or coated with cement, and the ground is made of rammed earth walls or brickwork, 1.5 m high. The angle between the roof and the ground should preferably be 30°C. On the roof ridge, install one ventilation tube every 4-5 m. The mushroom beds are arranged in 2 rows inside the mushroom house, divided into 6 layers, 4 m wide, 18 cm deep, with 45 cm between layers. The walkway between mushroom beds is 70 cm wide.

③ Underground mushroom house  In cold northern regions, underground mushroom houses can be used to cultivate mushrooms. This type of mushroom house is generally buried more than 1.65 m below the ground. In many areas, air-raid shelters, basements, mountain caves, and tunnels are often used as underground mushroom houses. Its advantages are high relative air humidity, small temperature changes, warm in winter and cool in summer,   and a long cultivation period. The disadvantages are inconvenient management and poor ventilation.

2. Mushroom bed Mushroom bed  is the bed for cultivating mushrooms. Its main forms include shelf-type mushroom beds, flat-bed mushroom beds, and box-type mushroom beds. At present, shelf-type mushroom beds are mostly used in production. 

(1) Shelf-type mushroom bed  Its setup in the cultivation room should be determined according to the size and structure of the mushroom house. The arrangement should be perpendicular to the orientation of the mushroom house. For example, in an east-west oriented mushroom house, the mushroom beds are arranged north-south; in a north-south oriented mushroom house, the mushroom beds are arranged east-west. The mushroom beds can be arranged in two rows, three rows, or more. The width of each mushroom bed should be limited to the extent that mushrooms can be picked from both sides to the center, generally about 1.5 m. If mushrooms are picked from only one side, the width should not exceed 1 m. The distance between layers of the mushroom bed is 60-70 cm, and the lowest layer should be more than 20 cm above the ground. The top layer should be 1.3-1.6 m from the roof.  The distance between mushroom beds should be 60-70 cm, enough for one person to move and operate.

The setup of mushroom beds should not only make full use of the area, but also ensure good ventilation and convenient operation. At the same time, it should be solid and sturdy, able to bear the full weight of the cultivation material and casing soil. Generally, each square meter must bear a pressure of 90 kg, otherwise safe production cannot be guaranteed. The materials for making mushroom beds can be obtained locally, generally made of bamboo, wood, or reinforced concrete. The bottom supporting materials are mostly bamboo poles, tree branches, hemp stalks, etc., which not only save materials but also facilitate air permeability, allowing good mycelial development.

(2) Flat-bed mushroom bed  When using air-raid shelters and mountain caves to cultivate mushrooms, the cultivation material is often spread in bed form. The bed width depends on the size of the cave. Generally, one-sided harvesting should not exceed 1 m, and two-sided harvesting can be 2 m wide. The bed edges are enclosed with bricks or wooden blocks. To increase the fruiting surface, the bed surface can be made arched or wavy.

(3) Box-type mushroom bed  It is suitable for mechanized and factory production of mushrooms, but the cost is high and the technical level required is also high. The cultivation box is made of wooden boards. The length, width, and height specifications of the box are 1×0.6×0.2 m or 2×1.2×0.2 m. In the mushroom house, the wooden boxes are arranged on specially made wooden racks, either stacked in overlapping rows or staggered in a triangular arrangement. Box-type mushroom beds allow manual control of temperature and humidity, have a compact production period, and high mushroom house utilization. At present, countries with high levels of mechanization and automation in the world mostly adopt this method.