Mushroom Housing and Composting
Booklet No. 441
Mushroom Cultivation: MCS - 3
II. Mushrooms Housing
A. Systems of housing
B. Housing material
A. Factors in compost preparation:
1. Compactness and water content
2. Acidity of a medium
5. Heat treatment
B. Ingredient of compost
C. Formula for Compost
D. Compost Yard
F. Characteristics of good Compost
In the previous two booklets on mushrooms (Booklet No. 439 Mushrooms in Human Life
and Booklet No. 314, Introduction to Mushroom Growing) the concept of mushroom growing
was introduced and the importance of mushrooms and their species was also elaborated. This
booklet gives detailed information about compost requirement and various systems of housing
for mushroom cultivation. Knowing all these a mushroom grower will be in a position to choose
the system suitable to the local conditions and resources available.
Dr. K. T. Chandy, Agricultural & Environmental Education
Cultivation of mushrooms is a very exact science. Briefly, the three main operations in
mushroom growing are composting, spawning and casing. While each of them is important for
getting a good yield, compo sting may be termed as the heart of the process and is therefore
the most important.
The first point that needs to be understood is that normal soil is not suitable for growing
mushrooms. Instead, the medium used is a mixture of various types of decomposed farm
wastes known as compost. The farm waste consists of wheat straw, paddy straw, horse
manure, poultry manure, cattle manure, fertilizers and certain other ingredients which help in
decomposing the straw. The material on which mushrooms are grown is called substrata.
For successful mushroom production, it is necessary for each grower to produce the
highest quality of mushrooms as economically and efficiently as possible. This can be
accomplished by meeting the requirements at low cost.
II. Mushroom Housing
There are three basic systems of mushroom growing in India. They may be growing in
shades trays and polythene bags. There are various types and designs of houses to
accommodate these systems to get more production per unit area.
A. Systems of mushroom growing
The systems of growing mushrooms are named depending on the material on which the
cultivation of mushrooms are carried out. Shelf system, tray system, growing in bags and floor
beds are four systems of mushroom growing. They are briefly explained here.
1. Shelf system
The mushroom houses are constructed with built-in shelves on which the beds are laid.
The shelves are either built in, or made up of wooden planks, plastic sheets, asbestos, steel,
etc. The shelves are about half a metre apart, the lower being at least 20 cm above the floor. In
this system spawning and cropping take place in the same room.
2. Tray system
The tray may be made from any material available locally. When we start the mushroom
growing at small scale with low expenses, fruit packing box may easily be converted into
mushroom trays. The size of a tray should be such that it can be handled and carried when filled
with compost A convenient size for each tray may be 100 cm long, 50 cm wide and 15-18 cm
All trays must be of uniform size to facilitate stacking of each on top of the other. Each
tray needs supports from all the four comers and is arranged at 30 cm high. This would allow for
a working space of 30 cm between two trays. Trays can also be designed in so many other
3. Growing in bags
The polythene bags of thick gauge, 45 cm deep with an approximate surface area of 0.1
m2 can be used. Such bags are capable of holding about 25 kg of compost, more quantity if it is
light and less if it is heavy. Usually they are kept on floor or on raised shelves. In limited
accommodation growing mushrooms is not economical in bags that are kept on since they
occupy more space, though suitable in caves or in an improvised low cost building such as
polythene house, where the investment and depreciation costs are not involved.
Compost for growing in bags should be a little drier about 62-65% at spawning
compared with 65-70% for shelves or trays. If the compost in bags is filled quite deep and
compact it may produce heat and it is detrimental to spawn. Bagging is therefore recommended
for cooler climate or where the temperatures are controlled.
4. Floor beds
Floor beds in ridges and furrows give more surface area, for the extravagant use of the
available space. The beds on the floor tend to dry up rather quickly, therefore, a very high
relative humidity has to be maintained. A polythene tent over the beds helps to maintain high
humidity in the air surrounding the beds.
B. Mushroom houses
With commercialization of mushrooms, many national and international groups are
setting mushroom farms. They are introducing a wide variety of designs and constructional
materials for mushroom houses. For setting a small scale unit, two layered brick wall with a
cavity in between or hollow concrete blocks are used for making mushroom houses. For roof,
asbestos sheets are used which are insulated with any conventional insulating material, thermo
cole, fibreglass, straw, etc.
A low cost construction is the polythene house. It has frame work of steeltube, covered
With 500 gauge clear polythene lined with insulating material like thermocole, from outside and
covered with black polythene. The outside sheet of black polythene is painted with aluminium
paint to protect the absorption of heat from direct sunlight Straw or grass thatched houses are
The material on which the mycelium grows is called .compost or substrate. The
properties of the substrate determine which fungi and microbes can grow in them. The
environment also plays an important role: humidity of the air, ventilation, shade or sun, and
temperature together with the internal condition of the substrate, determine whether the
mycelium can grow in the substrate. Some fungi can grow in a broad range of substrates, while
others are very selective. For example, pleurotus species, will grow on almost any broad leaved
tree wood, while shiitake (oyster mushroom) requires more specific trees to support its growth.
The better substrate meets the demands of that particular mushroom and it will be less suitable
for others. Selectivity depends on available nutrients, pH, microbial activity, aeration and water
A good substrate holding all these characters, suitable for a particular mushroom taken
for cultivation, will be higher yielder. By controlling following factors a good substrate can be
A. Factors in compost preparation
As discussed earlier there are several environmental factors and other factors which
affect the quality of compost.
These are as follows.
1. Compactness and water content
If the substrate is either too tight or too loose the mycelium (prime fruiting body) will have
difficulties in colonizing in it. In too loose conditions, mycelium needs more energy to reach the
next bit of saw dust or straw. If it is too compact, the mycelium can not breathe. Both low
oxygen and high carbon-di-oxide. concentrations will slow down its growth rate. Good aeration
is therefore necessary .
These conditions are also applicable to the water content of the substrate. A too high
water content results in clogging of the air flow. A too low water content prevents growth,
because of lack of water. Under anaerobic conditions, microbes will develop and give a foul
smell. They may also produce toxic metabolites during their growth.
Water content gives the percentage of total water. Only a fraction of this water can be
used by the mycelium. Therefore, the free water activity would be better measure. Free water
activity has to be regarded in relation to the water holding capacity. A very fine saw dust can
hold more water than relatively coarser saw dust.
2. Acidity of a medium
Most of the cultivated mushrooms prefer a slightly acidic medium to grow. The acidity
(PH value) can drop considerably during the growth of the mycelium. For example, shiitake
mycelium in wood logs will decrease the pH value from 5.5 to 3.8. The most commonly used
buffers to achieve a suitable pH in the substrate are gypsum and lime.
Measuring the pH value of the substrate should be a routine action take a representative
sample of the substrate of 5-10 g and put it in distilled water. Crush the substrate materials and
shake the water. Two methods can be used to determine the pH value of this solution i.e. with
paper indicators or with an electric pH meter. The paper indicator contain a number of
substances that change colour at different pH values. By comparing the paper with a colour
table, the pH value can easily be determined. Electric pH meter is expensive, so, convenient
method is to use paper and pH table.
Do not consider pH as a measure as such. It can be an indication of microbial activity,
which is influenced by the substrate contents. If the real problem is microbial activity because
improper pasteurization and conditioning, then increasing the pH value by adding a buffer
(chalk) is not a solution.
Usually the substrate consists of several materials. An even distribution of these is very
important. If there are lumps of supplements, then these are much more selective to
contaminants because the concentration of nutrients is very high at one spot. An equal
distribution is important for the mycelium too. The mycelium can only use the supplements
efficiently, if, it has easy access to them. The same applies for the moisture. Water should be
available in the same concentration every where in the substrate. In shiitake cultivation on
pasteurized substrate it has been noted that contamination with green moulds occurred in spots
where moisture had accumulated. By slitting open the plastic covering, the water could
evaporate and the shiitake mycelium would grow over the contaminated spots.
For some species (mainly Agaricus, but sometimes also Volvariella and Pleurotus) the
substrate needs fermentation in order to become suitable. If the undecomposed substrate is
spawned, the mycelium would die because of the heat generated by microbial activity. So it has
to be fermented first. Then It is given a heat treatment, and only then It is spawned. The process
will make the substrate more appropriate for the desired mushroom by degrading easily
accessible components. An optimal substrate is selective for the desired mushroom. This
means it is the best suited for this kind of mushroom and not for other fungi.
To reach a good fermentation, the size of the substrate heap is important. If the heaps
are too small, the temperature will not reach the desired level. Solid wastes have a poor heat
conductivity. The heat produced inside is not easily conducted to the environment. The
temperature can rise to 60°C or 80°C. The outside environment the heap however, will be
relatively cool. Therefore, the heap has to be turned. The inner core has to be on the outside on
the new heap and vice-versa.
5. Heat treatments
Substrates (composts) are subjected to heat treatment for controlling pest and diseases.
Several types of heat treatments are employed in mushroom cultivation. They are given here.
This will free the substrate from all living organisms. However, it requires sterile packing,
a special autoclave, a high pressure steam boiler and quite a lot of energy. Immerse in the
pressure is necessary to reach a temperature of 121° centigrade. Some organisms can survive
this treatment at 100°C also and these will grow very fast on the media used for cultures, like
agar and grain. They would contaminate the media and render them worthless. So, for spawn
and pure cultures it is absolutely necessary to sterilize. Plastic bags will crack more easily if they
have been sterilized under pressure.
This may require a less expensive steam boiler, because not much pressure is involved.
Many kinds of wood-degrading fungi can be cultivated after having applied either a complete
sterilization or a semi-sterilization.
If the farmers have the resources and the knowledge, they will sterilize substrates. After
harvesting few flushes, they change the substrate in order to avoid any carryover of the
contaminants. If the substate is sterilized under high temperature, it becomes degraded and
susceptible for mycellial growth. So semi sterilization is preferable to get more number of
flushes over a longer period.
This is aimed at killing unwanted organisms but keeping the favourable ones alive. To
reach this state a temperature of 60- 70°C has to be sustained for some time. Most of the pests
and diseases will be eliminated at this temperature. When pasteurization by steam is practised,
it is often followed by conditioning.
d. Immersion in hot water
This is also a form of pasteurization. However, it differs from pasteurization by steam.
The hot water will remove the easy accessible sugars and at the same time it will kill
contaminants. Coffee pulp and rice straw can be treated in this way for the cultivation of
Pleurotus. This method is very easy as it requires only hot water containers and means to keep
the water hot.
This is aimed at creating a suitable environment for the desired mushroom by promoting
the growth of thermophilic (high temperature loving) organisms, like some lower fungi from the
group of Actinomycetes. These. will transform the easily accessible sugars and discourage the
growth of competitors on these nutrients. The period of conditioning depends on the
concentration and type of nutrients to be transferred. The usual temperature is 480 centigrade.
This method is used in cultivating Pleurotus on wheat straw and com cobs, and Lentinus on
crop cobs. Substrate for Agaricus should first be fermented and then be pasteurized and
B. Ingredients of compost
The mushrooms are grown on a substrate which provides adequate levels of nutrients to
support the crop so that it can successfully compete with other micro-organisms. Traditionally,
partially decomposed compost with some additional supplements has been the principal
medium for providing required nutrients in artificial cultivation of the mushroom.
1. Base materials
These include wheat straw, paddy straw, maize cobs, and other similar cellulosic plant
waste with or without farm waste. Conventionally, wheat straw either alone or mixed with horse
manure, chicken manure etc., is most widely used as base material. In non-availability of wheat
straw, straws of other cereals, like rice or barley may be used.
The chief function of base material is to provide cellulose, hemicelluloses and lignin in
bulk. These materials also provide proper physical structure to the mixture to ensure the
necessary aeration for the build-up of microbial population and the subsequent spawn growth in
the compost. Rice and barley straws are quite soft and decompose quickly, leaving only a little
fibre for imparting a proper physical structure to the compost. Therefore, the type and quantity of
supplement should be discretely utilized at the proper time.
These are materials enriching the medium by nutrient addition and activating
fermentation. These may be categorized as given below.
a. Animal dungs
These include horse and chicken manure, the extremely variable manures in
composition. Nitrogen content may vary from 1-5 percent. In addition to nutrients, they
contribute greatly to the final bulk density of the compost. Cow dung may also be considered but
usually it is not found suitable.
b. Carbohydrate nutrients
From molasses, well brewers, grain and malt sprouts, carbohydrates are readily
c. Concentrate meals
These materials are commonly used for animal feeds and include wheat or rice bran,
dried brewer's grain, the seed meals of cotton, soya, castor and linseed. In these, both nitrogen
and carbohydrates are available rather slowly. Nitrogen Content may vary from 3-12 percent.
The oil and mineral content of some of these may be of significance in mushroom nutrition.
d. Nitrogenous fertilizers
Nitrogen in chemical fertilizers such as ammonium sulphate, calcium ammonium nitrate
and urea, are rapidly released for the quick growth of microbial population.
e. Mineral supplements
Muriate of potash and calcium superphosphate are added to furnish mineral
f. Materials for greasiness
Gypsum and calcium carbonate serve to precipitate suspended colloidal materials and
The choice of materials within each category is largely determined by cost factors and
their availability locally. Composts prepared from horse-dung mixed with straw are termed as
"natural", whereas they are called synthetic if the base material used is mainly straw without
bulk animal manure.
C. Formula for compost
The compost ingredients discussed in previous para may be mixed in varying quantity.
Some of the formula are given here.
The formula suggested by the College of Agriculture, Solan, in the "Special Priced
Bulletin" of IMGA, Mushroom Cultivation In India, Oct. 1980." Ingredients are as follows.
1. Wheat straw -300 kg
2. Calcium ammonium nitrate or Ammonimn sulphate (20.6 N) -9 kg
3. Urea (46% N) -3.6 kg
4. Sulphate of potash or Muriate of potash -3.0 kg
5. Superphosphate (18% P 2°5) -3.0 kg
6. Wheat bran or -30 kg
7. Spent brewe's grain (biproduct of breweries) -40 kg
8. Gypsum -30 kg
9. Nemagon (60%) or -40 ml ,
Furadon -36 -150 g
10. Lindane or BH.c 5% dust -250 g
11. Molasses (to be used only when using wheat bran) -5 kg
Synthetic compost with chicken manure suggested by Dr. W.A. Hays and Mr.
1. Wheat straw -1000 kg
2. Chicken manure -400 kg
3. Brewer's grain -72 kg
4. Urea -14.5 kg
5. Gypsum -30 kg
For horse manure natural compost
1. Wheat straw -500 kg
2. Horse manure -1000 kg
3. Chicken manure -300 kg
4. Brewer's grain -60 kg
5. Urea -7kg
6. Gypsum -30 kg
(Suggested by Punjab Agricultural University, Ludhiana)
1. Wheat straw 300 kg
2. wheat bran 7.5 kg
3. Poultry manure 60 kg
4. CAN 6 kg
5. Urea 2 kg
6. Superphosphate 2 kg
7. Ptassium sulphate 2 kg
8. Gypsum 30 kg
9. Lintex 60 ml
1. Wheat straw 300 kg
2. Molasses12 kg
3. Urea 4.5 kg
4. Wheat bran 50 kg
5. Muriate of potash 2 kg
6. Cotton seed meal 5 kg
7. Gypsum 15 kg
Formula 6 (this formulae is given by JPHR Bangalore
1. Wheat straw (6 inches pieces) 300 kg or paddy straw 400 kg
2. Ammonium sulphate or CAN 9 kg
3. Super phosphate 9 kg
4. Urea 4 kg
5. Wheat bran
6. Gypsom 12 kg
7. Calcium carbonate 10kg
Formula 7 Suggested by JPHB Jabalpur
1. Paddy straw 150 kg
2. Maize stalk 150 kg
3. Ammonium sulphate 9 kg
4. Super phosphate 9 kg
5. Urea 4 kg
6. Rice bran 50 kg
7. Gypsum 12 kg
8. Calcium carbonate10 kg
9. Cotton seed meal 5 kg
Formula 8 suggested by JPHR Bangalore
1. Wheat straw 250 kg
2. Horse manure 430 kg
3. Chicken manure 100 kg
4. Brewer’s grain 30 kg
5. Urea 7 kg
6. Gypsum 20 kg
Formula 9 anonymous
1. Wheat straw 300 kg
2. Chicken manure 120 kg
3. Rice bran 20.6 kg
4. Brewer’s grain 22 kg
5. Urea 6 kg
6. Cotton seed meal 5 kg
7. Gypsum 10 kg
Formula 10 Anonymous
1. Paddy straw 3000 kg
2. Chicken manure1500 kg
3. Wheat bran 125 kg
4. Gypsum 90 kg
Formula 11 Suggested by Seth 1975 for long method of composting
1. Wheat straw 1000 kg
2. CAN 30 kg
3. Superphosphate 25 kg
4. Urea 12 kg
5. Sulphate of potash 10 kg
6. Wheat bran 100 kg
7. Molasses 16.5 kg
8. Gypsum 100 kg
9. Nemagon 266 kg
Formula 12 Suggested by IARI
1. Horse dung 1000 kg
2. Wheat straw 350 kg
3. Urea 3 kg
4. Gypsum 30-40 kg
Formula 13 Suggested by Hayes and Randle in 1956
1. Horse dung 1016 kg
2. Chicken manure 101.6 kg
3. Molasses 38.1 kg
4. Cotton seed meal 15.24 kg
5. Gypsum 15.0 kg
Formula 14 Suggested by Takpashi from Japan in 1975
1. Rice straw 1000 kg
2. Urea 5 kg
3. Calcium cynide 10 kg
4. Ammonium suphate 13 kg
5. Calcium carbonate 25 kg
6. Calcium superphosphate 30 kg
Formula 15 Formulated by shin et al from Korea in 1971
1. Rice straw 1000 kg
2. Chicken manure 100 kg
3. Urea 12-15 kg
4. Gypsum 20 kg
Formula 16 Formulated by Ho in Taiwan in 1978
1. Rice straw 1000 kg
2. Ammonium suphate 18 kg
3. Urea 4.5 kg
4. Calcium superphosphate 18 kg
5. Calcium carbonate 27 kg
Formula 17 Formulated at IARI, New Delhi as synthetic
1. wheat straw (chopped) 1000 kg
2. Wheat bran 80 kg
3. Urea10 kg
4. Ammonium suphate or CAN 10 kg
5. Gypsum 40-50 kg
D. Compost Yard
The compost yard should be prepared near the growing site on cleared concrete or
pucca floor at a higher level to prevent the run-off water from collecting near the heap.
Composting is usually done in the open, but is has to be protected from rain, by covering it with
polythene sheet. It can be carried out in a shed with open sides to shelter it from rain.
Composting is accomplished by piling up wetted inputs in a heap. When this is done
properly the temperature inside the heap begins to rise due to the aerobic fermentation brought
about by bacteria and other micro-organisms. It is not unusual to reach a temperature of 70-
74°C, in the centre of the heap on the third day of compo sting. Because of the high
temperature which build. up in compo sting heaps, thermophilic and thermotolerant organisms
quickly dominate over the mesophiles. In the early stages, the natural mesophile flora subside
but the population of the thermophil's and thermotolerants increase. Bacterial population
dominates and their rapid increase in number coincides with maximum heat generation,
consequently, the temperature build up. This is followed by a relatively prolonged stage
dominated by thermophiles mainly thermophilic actinomycetes. As the fermenting organisms
require both water and oxygen, the heap is watered frequently and aerated by turning.
During composting, ammonia gas is liberated and some of it is lost to atmosphere, but
some is consumed by bacteria to produce nitrogenous intermediates which are eventually
converted into protein by another kind of bacteria. There is an optimal composting time beyond
which the compost suffers steady decrease in potential productivity.
There are two methods for preparing mushroom compost, the long and the short
method. The 'long method' is considered to be primitive and unsuitable for commercial
cultivation. The 'Short method' is quick and a definite advance over the earlier technology.
However, the 'long method' is still relevant for the growers in India who cannot afford the
expensive technology required for the short method
1. Long method
Step by step procedure of preparing compost by long method is given as follows.
a. Wetting the straw
The first step in the compo sting process is 10 wet the straw. Fresh dry straw resists
water absorption and unless it is persuaded to absorb water, it will not soften and unless it
softens it will not take more water later.
The straw is spread thin over entire floor of the composting yard. It is then gradually
wetted by sprinkling water, gently, till the straw takes no more water. The straw is then turned
for even wetting. Again water is sprinkled till it can absorb no more water. At this stage, the
water content is 75% and for most composts this point is reached when the compost is just
saturated and before any run-off occurs. One tonne of dry straw will require almost 5,000 litres
of water to bring it to saturation.
b. Mixing and heaping
After the straw is wetted, the supplements excluding the gypsum are uniformly scattered
over the straw and mixed. Some growers prefer to mix half the supplements at the beginning of
composting and the remaining half after the first turn. After mixing, the mixture is finally stacked
in a heap. A heap one metre high, one metre wide and of suitable length has been found
convenient. The straw should be firmly but not compactly compressed into the mould.
The dimensions of the heap can be adjusted according to the size of straw and air
temperature. The principle is that longer the straw, bigger the heap. If compo sting is done in the
cooler months when the temperature ranges between 10°C and 18°C, a small heap would be
unable to retain heat and moisture and the compo sting would be unsatisfactory. During the hot
weather, generally, and in particular, in tropical and sub- tropical regions, the temperature
difference between inside compost and the surrounding air is too small to produce chimney
effect necessary for compost ventilation. Core ventilation does not take place. As a rule
undesirable acid zones occur inside the compost. In such cases, relatively narrow heaps would
be more suitable.
c. Turning schedule:
It is important to ensure that the heap attains sufficiently high temperatures (70°C -75°C)
to bring about the correct compo sting otherwise the compost will lack the necessary nutritive
value so essential for a good crop. Care must also be taken to see that over compo sting does
not take place. Open the heap and remake it a number of times and for this purpose, the time
schedule suggested is:
Just before - Wet, mix and stack the heap starting
4th Day - First turning
8th Day - Second turning
12th Day - Third turning
16th Day - Fourth turning
20th Day - Final turning and filling in the trays.
Nitrogenous supplements and carbohydrates are mixed just before starting. Gypsum is
usually mixed at the third and fourth turning in equal quantities. During the final turning, 40 m1
malathion diluted in 20 litres of water is sprinkled. Any other available insecticide, like BHC or
lindane can also be used. The above schedule can be altered if the conditions within the heap
so require. The guiding principle is that the heap should be opened when the temperature within
rises no further. For horse dung manure, the final turning is given on 16th day rather than on
2. Short Method
The short method consists of two phases: phase I and II. The procedure for phase I is
similar to the initial stages of the long method except, that turnings are given sooner, the first on
3rd day, the second on 6ft. day and third on 9-10th day when gypsum is added. The compost is
now ready for the phase II or the peak heating.
Peak heating is recognized as the microbial-composting stage and is an integral part of
the total compo sting process. The purpose behind phase II is to promote such conditions in
which the thermophilic flora thrives and pasteurization of the compost. By heating the compost
and the surrounding air, for a brief period to temperature of about 60°C, virtually all important
parasites and pathogens can be eliminated. Heating may be done in two ways.
a. Heating in tray beds
The trays are filled loosely with the phase I compost and are stacked one over the other
leaving about 20 cm space between the two trays for the free flow of steam and air inside the
pasteurization room. The compost in the trays will begin to heat up through the microbial
activity. The room is now sealed to avoid any le1kage of heat, and to let the steam in, to raise
the temperature of tray-beds to 520 -540 centigrade. Care is taken so that all the trays in the
room get uniformly heated to the required temperature. The trays which do not attain this
temperature will produce compost of inferior quality. After maintaining the temperature at 52 -54
°C for 2 to 4 days, the temperature of the compost is further raised to about 60°C for 4 hours.
The steam supply is now shut off and the temperature of the room is allowed to fall gradually @
20 -30 per 2 hour by sufficient ventilation to the original level of 52-540 centigrade. This range of
temperature is maintained for another 4 days, when ammonia has disappeared from the
compost. It is now allowed has disappeared from the compost. It is now allowed to cool to 24 -
250 centigrade. A very high humidity in the air should be maintained throughout the phase II to
avoid excessive drying out of the compost. Compost moisture should be readjusted if
b. Bulk composting
In this method, peak heating (pasturisation) and conditioning of compost is carried out in
a so called 'tunnel' or bulk room. This method was developed in Italy and France and at present
is successfully used in the Netherlands and other countries.
The phase compost of the short method is loosely heaped on the floor of a peak heat
room or 'tunnel' which has to be built especially for this purpose. After filling, the doors, windows
and ventilators are shut off and the room made airtight. The air temperature of the room is
raised 57-58°C by introducing steam for pasteurization. At this point the temperature in the core
of compost would be around 62-63o C. After 3-4 hours fresh ail is let in so that the temperature
is gradually lowered to 46-48oC. This temperature is maintained for 4-5 days for conditioning of
the compost. The compost after conditioning is allowed to cool to room temperature, spawned
and filled. The compost prepared by this method is particularly suited for filling in bags or
making shelf beds.
F. Characteristics of good compost
An experienced grower can judge the state of his compost by the use of his hands and
nose. A good compost made from horse manure should be brown, with a distinctive but in
offensive smell. There should be no smell of ammonia, which can be readily detected. When
squeezed in the hand, no water should trickle through the fingers, yet it should be wet enough to
moisten the palms. When rubbed between the fingers there should be no feel of greasiness.
The moisture content of the compost should be 2/3 of its weight and pH around normal.
It is very clear that the success of the mushroom cultivation depends on the inputs and
media for growth. Compost used for mushrooms should be prepared scientifically by anyone of
the methods described, e.g. long method and short method. In Indian conditions, for growing
mushrooms, long method, method of compost preparation is best because it can be prepared
at village levels and does not need much technical expertise, machine and equipment. While for
commercial cultivation, short method of compost preparation is recommended because it is
latest modification from the long method. Ingredient of the compost may be chosen from the
formulas described, according to the availability of the materials. Before going for spawning the
quality of the compost must be ensured to get a good crop.