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Development of mushroom industry in the face of decreasing income from mushroom growth

Development of mushroom industry in the face of decreasing income from mushroom growth

Nikodem Sakson

Presentation no „Mega konferencja” 6 September 2018 Janów Podlaski

www.pieczarkalia.pl/archiwum/mega-konferencja-2018

 Decreasing Income

Income from mushroom growth have been decreasing slowly for last few years. This decrease is estimated at 30-40 percentage points. The reason for this is concentration of sales to retailers, who maintain fixed prices in Euro, that are paid to providers, although the production costs are constantly rising. This situation hasn’t changed for years. EU doesn’t want to intervene into mushroom market. The trend of decreasing income from mushroom production has Europe-wide range.

During the last period, the decrease in income has sped up, because of increase in work costs and energy etc. This increase will be constant. It can get even bigger if the inflation is higher. Another dangerous thing are higher prices of raw materials, like substratum, when there is a lack of straw on the market. One has to take into consideration decreasing amount of public help, whether to single investors or for the groups of producers. Some kind of security for this events can be a weakening of zloty for those producers, that export mushrooms and get constant price in foreign currency. But the example of Pound shows that this rule is not proven. The question still remains, what is next after Brexit? There is no doubt nowadays, that the state of Polish mushroom industry is dependent on EU, and not Polish markets.

At the moment the industry reacts to the decrease of income by increasing the surface area of growing space and vertical concentration. There are also fewer producers, which is accompanied by bigger production (that are the result of new investments into increase of the surface) in remaining producers. One has to consider the possibility that those trends will run out because of restrictions of growth, that are the result of lack of workers for picking mushrooms, and problems with managing bigger companies.

What actions are being taken to counteract the decrease?

Those actions can be divided into four groups:

  1. Improvement of organization and reduction of costs of production. Those themes are being discussed during meetings with producers, that are written about in “Pieczarka” bulletin.
  2. Acquisition of bigger parts of profit margins in circulation of mushrooms by its producers.

Attempts of acquisition of parts of profit margins can be observed in different improvement strategies that can be noticed in Europe. For example:

– Monaghan Mushrooms. Analysing changes that are done in this company, it can be pointed out, that it is trying to improve its financial results by vertical integration; it tries to take over profit margin from raw materials, shorten mushrooms’ transport by buying mushroom production plants in countries, where there is the biggest consumption, sell mushrooms individually, under its own trademark to retailers, that would allow it to gain additional profit by gaining consumers’ approval.

– Green Yard. This company can potentially gain increase in margin profits by rationalization of transportation and a position of complex supplier of retailers and developing their own trademark.

– Polish mushroom producers. They have limited possibilities of increasing the profit margin, because they usually provide mushrooms to brokers, who are focused on providing the merchandise to retailers, and it is wholesales that are focused on supplying fresh markets, restaurants etc. in which the origin or trademark is not important. Besides there is no such thing as „Polish mushroom” trademark, marketing abroad is done on a limited scale, and being a part of commercial events is rare.Stands available during these events are modest. Whereas producers groups, that have developed in Poland, absorb the advantage customers have over the producers in comparison to other countries, where such groups are basically non-existent.

  1. Other potential profits that can be gained from running a mushroom production plant: sale of substrate after the yield for its further processing, connecting aggregates that are in producer’s possession into energy networks etc.
  2. Technological changes in the process of mushrooms production.The main goal would be to maximize the income and decrease of production costs.

The state and improvement of technology of mushrooms growth in Poland

Technologies of production of raw materials and of growth of mushrooms nowadays point out to the limit of growth at the level of average of 33 kg/m2 of mushrooms during the year (M. den Ouden Mushroom Signals). Both compost and substrate that is produced nowadays as technology of growth don’t allow reaching stable yield of mushrooms. The fluctuations are significant and equal from 28 to 40 kg/m2.

In the situation when to cover the costs of production it will be necessary to reach the average yield of around 33 kg/m2 of mushrooms yearly, this fact will force the producers to change the model of improvement based on known technologies, developed during the production practices, to the model based on development of new technologies based on results of scientific research. Those new technologies will have to be able to maintain competitiveness of Polish mushrooms on the EU markets by constant increase of yield and maintaining highest quality, usefulness for long transportation, and with the costs lower than the competitors. It also will have to stop the decrease in profitability of production. It will be also necessary to limit or even eliminate picking during weekends and implementation of gathering adapted to client’s needs.

  1. What yield and quality of mushrooms are provided by changes in technology of mushrooms production developed in Poland?

Developed technology (Pieczarkarnia Chełkowscy, Hajduk raw materials, E-58 Premium Euromycel mycelium) allows to reach a yield of 40 kg/m2 in three flushes, with limited variability of volume weight of picked fruiting bodies (white and shapely) and minimum seven days shelf life, and minimal loss of weight of fruiting bodies, that are correctly cooled and stored after picking (phot.1).

Phot. 1 This is the quality and size we are expecting to get constantly.

Keeping the constant volume weight for the whole period of yield allows to increase the efficiency for 30%. It would allow for keeping the need for the workforce for picking at the same level and increasing the salaries without increasing or reducing the cost of picking. Those results were achieved in conditions that were unfavourable for growth – at the end of spring and at the beginning of summer, were the air temperature was hot, the humidity was low and there were a lot of changes of parameters during the day in very short periods of time. This would mean, that seasonal changes in yield could be eliminated.

  1. What elements of technology were changed to gain appropriate benefits:
  2. Using supplements in average doses of 2,5 kg/m2 (Aril KK Standard) with the amount of substrate on the level of 81-83 kg/m2 and with balanced dosage of water poured into the substrate. Aril KK Premium is used – it is a new generation supplement, which has features similar to the compost.It enlarges the water capacity of substrate, allows for better control of air temperature during the whole process of production, which reduces the cost of cooling the substrate (“Pieczarka” Bulletin no. 4/2017, 1/2018and 2/ /2018).
  3. Controlling the way mushrooms behave during the period of growth based on the process of evapotranspiration with the usage of Piche’s evaporimeter. Right now tests are conducted with using this evaporimeter with a bigger area of the paper roll, which would allow for the hourly reading.
  4. Efficient system of regulation of air humidity.
  5. A program of additional irrigation before the yield begins.
  6. Controlling the ORP of water that is used in mushrooms production and using calcium chloride.
  7. Growth in conditions of high overpressure of air in the cultivation hall, which allows for an equalized air movement in every spot of the shelf and eliminating loses which are a result of unequal air movement. At the moment those loses in Poland are from 5 to 15% depending of the cultivation halls construction or equipment. It also allows for achieving needed temperatures in the substrate, which is very important when using substrates that are highly active. Thanks to this the nutrients are used more efficiently and the loss of energy which is a result of development of unwanted microflora is prevented. The other thing is controlling the way the mycelium behaves in the periods between the flushes. This effect was achieved by installing a new fan produced in Promont. It has a wide range of static pressure (nominal is 1850 Pascal’s), which by changing the rotations of the fan can be adjusted to every phase of growth and to the experiences of controlling the production process. To keep the higher overpressure in the cultivation hall, Promont additionally designed new type of over pressurising shutters with the possibility of setting the starting value of overpressure manually. Additional values of installing a new Promont fan allow for introduction of new solution into air coolers. Thanks to this technology accumulation and retention of condensate between the lamellae of the exchangers were eliminated and resistance of air flow in the coolers was reduced. Also the transportation of condensate on the heater was eliminated.

Another phase of modernization of equipment for controlling the parameters of air is expansion of coolers – enlarging the area of heat exchange. It will allow to increase their cooling efficiency and reinforcement with water (aqueous glycol solution) of higher temperature, without reducing the effectiveness of air cooling. At the same time desiccation of cooled air will be reduced.

A device that would pour water on the fans turbine to raise the humidity of exiting air will also be needed.

  1. Selective picking. It was observed, that even though selective picking was implemented there was an influence on the yield with maintaining constant volume weight of different picking brigades was equal 2 kg\m2. That means that different workers pick different number of fruiting bodies at the same amount of time.

Changes in the technology of growth described above were verified in practice. Their spread is conditioned by different factors, such as:

  1. The ability to use supplements chosen by the mushrooms producer. Right nowit is very limited. It usually needs independent sowing using a combine, during loading to the cultivation hall.
  2. Piche’s evaporimeter is burdensome in usage, because of its size and of the fact it can be easily damaged during the yield. Maintaining previously specified levels of evapotranspiration means that the air’s parameters need to be set manually; mainly the humidity, which in this situation is a priority. To maintain the ratio of evaporation and the relative level of humidity some experience is needed. Some work was undertaken to construct an evaporimeter that would allow to measure the level of evapotranspiration in feedback system, that would send a signal to the controller, which could make the process of maintaining desired evaporation level automatic. One has also to assess the ratio of evaporation and the way mushrooms behave and correct it if needed.
  3. The humidification systems usually work inefficiently. That is why a system of humidifying the floor of cultivation hall has to be installed. In case of a drop of relative humidity in the cultivation hall this system is activated first, and then the device to humidify the air. If the air movement is high there is a need to keep the constant level of relative humidity in the air at 94% during the picking period. In other cases the evapotranspiration is too high, and the fruiting bodies grow too fast and lose their weight.

To maintain high overpressure special kind of fans and coolers are needed. To control the level of overpressure one has to have a fitting sensor, that would be connected to the controlling system. This solution is being researched.

  1. Can systematic increase in yield improve the economic situation of mushroom producers? The answer is the worth of additional kilogram of yield gained by changing the technology. Assuming that the mushrooms are being grown on the phase III substrate and that there are 8,5 cycles in the year, with the price of 3,50 – 4,00 Zlotys (after subtracting the cost of picking) we get the amount of 29,75 – 34, 00 PLN/m2. When the area of growth is 1000 m2 the amount equals to 29 750 – 34 000 zlotys. Assuming that the average yield is 32 kg/m2 that means that the average difference in the potential income (8 kg/m2 of potential increase) means that the potential increase of income is from 238,00 to 272,00 PLN/m2. With the growth area equal to 1000 m2 the potential increase of income can be equal 238 000-272 000 zlotys yearly. The higher the increase in yield, the higher the additional income, because the constant costs are lower, they are divided into bigger mass of produced mushrooms. The costs of production are also lower, the yield is higher when the raw materials costs stay the same. Those effects can be achieved without a demand for more workforce, because the higher yield is achieved by enlarging the weight of the fruiting bodies, not their amount. Additionally maintaining good conditions of growth of mushrooms reduces the losses that are the effect of diseases, and high overpressure keeps the dipteral away from the cultivation hall. It didn’t increase the cost of disinfection treatments, because those results were achieved without using pesticides during the production in cultivation halls, where there was no thermal disinfection.
  2. Who are the proposed changes addressed to and what is the industry’s reaction on the proposed directions of development of technology of growth?

Changes proposed in this article will be made mainly by market. Those mushrooms producers will be viewed as potential clients, whose main goal of growth is gaining profit, and who will base their production decisions on economic calculation, and who analyse received information based on their merits. So the credibility of those information is not based on the person that gives them. Those producers are oriented towards development based on scientific research and results of developing works. They accept the fact, that proposed changes come with a certain risk and implementation costs, as with unexpected effects. They also accept the need of some organisational effort and gaining access to employees that are interested in changes of technology of production, independently of the size of the company. They are keen on further learning and studying and do not accept the myths that are essential part of behaviour and interpretation of events that accompany technology of growth in its current state. The alternative solution to this is improving current technology in its current concept of production based on experience and development through mastering the art of cultivating mushrooms.

Proposed change in the technology of growth is not met with interest in Poland nor in Europe. It is too radical and it significantly differs from currently used technology, which is promoted intensely by Dutch. Lack of interest in this technology by producers from different countries can be very favourable for Polish producers, when it will become more widespread, because it can provide competitiveness. The more the technology is opposed and the profits are bigger, the more significant the level of competitiveness.

Noticeable change in mushroom producers’ behaviour in Poland to its growth is increasing interest in supplements.

What is next?

Is the answer to the question: which direction will the mushroom production system in Poland take in the perspective of longer amount of time?

It is my point of view, that more modern system is producing mushrooms on more industrial level. The main weakness of current system is the human factor. This factor’s influence on the production results has to be minimalized because of the availability of workforce and the level of their qualification.

Research and developmental work

Research and developmental work are being conducted in Poland on wide scale. They should be concentrated on goals, that will allow the producers to gain bigger profit by increasing the yield, without or with minimal increase of the costs, and that would allow for an industrialization of the process of mushrooms production:

  1. Standardization of raw material and development of their production, especially substrate. Standardization is a set of actions, whose goal is to develop a technology of production that would allow for a repetitive quality and ability to produce substrate that would guarantee the expected level of yield even above 40 kg/m2 (under condition that the control of mushrooms behaviour in the cultivation hall is proper). Substrate’s production must also solve the problem of unpleasant odour and better use of straw, loss of which is up to 40% during the production. The question remains: can used substrate be reused as a substrate with new assumptions? New supplements for substrate are meant to create the conditions for a mushrooms equal yield in every flush – at the same level as during the first flush. Further works will concentrate on the composition of supplements. Supplements have to be better used by mushrooms and support nutrition in the second and third flush. There are some works conducted with using hydrogel and micro- and macro elements that support the nutrition.
  2. Automation of the process of growth of pins and fruiting bodies. It has to provide: maximal yield of the best quality, equal to the abundance of substrate, the possibility of controlling of the produced assortment of fruiting bodies – in time adjusted to received orders. It allows for effective use of robots during the picking process thanks to observation of the behaviour of pins and fruiting bodies, prediction of their behaviour and its effective controlling.
  3. Introducing robots into picking process. Benefits of introducing robots is not only gradual substitution of human workforce by them, but possibility to conduct picking of the fruiting bodies with the biggest volume weight and best quality during whole 24 hours. This issue is the interest of the Polish company FX-Tronik. A project POIR.01.02.00-00-0239/17 was submitted in the 8/1.2/2017/POIR INNOSBZ competition. “The effect of the project’s implementation will be an autonomic system of controlling and picking mushrooms. Unique qualities of this system, that differentiates it from competition is: full automation of mushroom picking and high efficiency, universality and mobility, monitoring of mushrooms before the yield, scalability, cooperation of any number of devices”. Other studies are conducted by Dutch company Cerescon B. V.
  4. Elimination of losses caused by disease and pests with minimal use or eliminating pesticides. In number 2/2018 of “Pieczarka” bulletin a research program was described, which main goal is to use mycoselective casing soil and mycoselective substrate for mushrooms production.
  5. Introduction of new, more demanding races of mushrooms into the production process. Those races have big volume weight, have other shapes and colour, and need best conditions to grow and reach enough substrate. Changes in this field are minimal.
  6. Energy savings. The energy can be saved not only by using new, modernised installations or new Energy sources, but also by introducing such solutions into production process, that would use the smallest possible energy for one unit of yield.

Nowadays there are a lot of companies conducting improvement and research programsthat are financed by EU or by private funds. There are or emerge R&D (Research & Development) centres. The scope of those researches have a developmental trend. Scientific backgrounds are created and developed in companies producing materials and in new business entities receiving national or EU’s help for their research, main goal of which is to create innovation.

But conducting research alone doesn’t translate into success – a new way of approach is needed. First of all they have to concentrate on industry’s essential problems and to solve them in an innovative way. The researches have to be conducted methodically, and their results have to be quickly implemented into practice. In my opinion, presenting a new way of approaching technology’s development, which is based on the statement that the cultivation of mushrooms is controlled process of its nutrition, gives us such possibilities. Especially taking into consideration that academic achievements in this field are very big. From the methods point of view it is essential that the rule that one experimental room cannot be occupied by research in which different variants concentrate on different activities of the substrate, be obeyed. In these situations the results can be more dependent on the microclimate, which could be more fitting to Agaricus, and influence its yield, than on variant, which would need different microclimate conditions.

The industry will decide which way the development in Poland will go. Independently the technology of growth will develop, based on achieved results and conducted research. The increase in the level of yield is still possible over previous level of 40 kg/m2.The knowledge in this domain will still be gathered and verified in practice.

Polska wersja artykułu / Polish version

NEW: What’s next with the standardization of substrate?

Biuletyn Producenta Pieczarek PIECZARKI 1/2018  S. 30-32

What’s next with the standardization of substrate?

Dr Nikodem Sakson, Poznań

I asked the question in the last issue of the Bulletin about the possibility of standardization of a substrate used in growing mushrooms based on the usage of cellulose supplements. It has been three months since then. What has happened during this time that would bring us closer to answering this question? A number of tests have been conducted in laboratory and a process of implementation of Aril KK Premium has been started.

Laboratory tests

A number of tests have been conducted using Petri dishes and containers with 0, 5 kg of substrate in them. (Photo. 1). Previous assumptions that mushroom’s mycelium is going to digest new supplement and that it can be a substantial component in nutrition of Agaricus have been confirmed. Scientific tests from the eighties are being used here. They showed that the main source of energy nutrients for mushrooms is straw (90%), and only the rest (10%) is biomass consisting of dead microorganism that underwent the process of maturation. All of this is a confirmation of the assumption, that digestibility of glucose is improving with the amount of torn fibres in straw, which allow mycelium to gain easier access to cellulose and hemicellulose. All of the above was the basis for further work with this supplement.

Tests during production

Usefulness of new Aril KK Premium and other supplements during a production of mushrooms on phase 2 substrate in a cube was being tested in the area of few square meters in cultivation hall. The results indicate usefulness of the new product. There was a several per cents increase of yield of a very good quality on a very good quality substrate, on which for comparison purposes the yield without the supplement was 28,7 kg/m2. There was a significant increase of quality in second and third flushes, with a very small percentage of fruiting bodies that could be qualified as the weakest (class C). In addition, the fruiting bodies had better colour and their features showed better effects after being processed. Further actions in implementation and testing what kind of results could be achieved on a wider production scale were taken.

Similar tests with Aril KK Premium were conducted in a cultivation hall on a phase III substrate with mushrooms produced for a fresh market. Tests confirmed an achievement of assumed effects like:

  • quicker regeneration of the substrate and dissolving of the supplement in substrate few days after being placed on the shelf,
  • lower rate of substrate activity, easier control of thermal effects,
  • the beginning of the yield started a day earlier,
  • better spread of fruiting bodies,
  • significant increase in the quality of fruiting bodies and increase in yield in second and third flush,

 

First implementations

At the time of publishing of this article yield in full six week cycle wasn’t conducted. That is why only occurrences accompanying production with Aril KK Premium until the first flush can be pointed out. They confirm the changes that were mentioned in parts 1-3 of this article. Further observations can be made:

  • The substrate has to be properly placed on the shelf. If it is not compact enough, it is easy to cause overflowing of the substrate, which may result in its local rotting. It is a result of greater water capacity of the supplement. It is also harder to maintain the temperature of the substrate up to the moment of putting water into it. Pillow effect. On the other hand, if the substrate is compacted too much the result is inability of putting water into it, which makes the cooling process harder and excessive humidity in places of contact between the substrate and casing soil.
  • The supplement has to be mixed very carefully with the substrate. Assumption that maximum amount of supplement should not be higher than 20% of substrate’s volume is being verified. Only in this case the effect of surrounding of a straw blade by a supplement can be achieved, without creating places where there is only supplement, far away from the mycelium, which makes it harder to transfer, especially taking into consideration its high humidity.
  • Thermal effect is still present during production on phase 3 substrate. Aril KK Premium supplement makes it easier to control, because of lower protein content. The results of using this supplement are achieved only when substrate’s temperature is no higher than 25-27°C before the shock. It can be done by lowering the temperature early enough, at the time of beginning of putting water into the substrate and raising the temperature of cold substrates, for example when it is 23°C, and with addition to intensive movement of the air to nullify the temperature difference between the air and the substrate.
  • it can be assumed that. when mushrooms have bigger nutrition resources, it is easier to spread the flush. Tendencies of spontaneous spreading out can be observed, in the same conditions as during binding without the supplement. The first buds appear a day earlier, and fruiting bodies have significantly better quality.

Nevertheless the main goal is to increase the yield in the second and the third flush with a significant improvement of quality. One has to wait for the full assessment.

Usage of Aril KK Premium is in the implementation phase. There is not enough data about the supplement’s effects during the process of mushroom production. As an innovation it can be divided, which means that it can be implemented gradually, starting with smaller dosages and only in some parts of the crop.

Polska wersja artykułu / Polish version

NEW: Could supplements make standardisation of substrate possible?

Biuletyn producenta Pieczarek PIECZARKI 4/2017  S. 32-36

Could supplements make standardisation of substrate possible?

dr Nikodem Sakson, Poznań

Changing quality of substrate is a fact. There are many reasons for this. One of them is that methods of controlling the process of compost production are not precise enough. You can find my propositions of changing this status quo in the last issue of Bulletin. Nevertheless solving the problem of producing substrate of stable quality can be resolved by actions taken in compost yards. Lack of changes in the quality of compost is the reason of searching for solutions allowing for standardisation of substrate on mushroom farms. One of these solutions could be usage of new generation substrate supplements that are based on high content of easily available cellulose and hemicellulose. They are called cellulose supplements for substrate.

Mushrooms intake of nutrients from compost takes place in two forms. The first is by dead microorganism that is in compost after its maturity phase, the other is left over degraded straw and supplements.

To improve the quality of substrate different supplements are used. They can be divided into two basic groups:

  1. Compost supplements. Their role is to maintain desirable ratio of carbon to nitrogen and to maintain availability of carbohydrates and nitrogen during composting process. For further information on this topic read my article in Bulletin no. 3/17;
  2. Substrate supplements, for differentiation called ‘feeding supplements’. Feeding supplements used nowadays do not allow for full standardisation of substrate. The reason for this is that when deficiency of nutrients is high enough, maximum dosages of feeding supplements cannot reduce it. Those limitations are the result of the way feeding supplements influence thermal effects. Limited, in given time, high assimilation of nutrients that the feeding supplements are containing is also the reason. A new formula of supplements is based on ideas taken from complete feed for animals. It means that the content and availability of nutrients can allow for mycelium to feed on them the same way as on compost. Hence the feeding supplements have to meet the following criteria:
  • They have to absorb water (fully moisturize itself) during few hours since introduction to substrate.
  • The transfer of nutrients from feeding supplement to mycelium should be 50% of their content during 72 hours.

The ratio of nutrients and their treatment is based on scientific researches that are the basis of modern biotechnology. Raw materials from grass fulfil these criteria. They undergo the processes that allow for their easier availability (as in compost).

What goals can be achieved when using feeding supplements that are rich in cellulose?

  1. Reaching projected volume of yield, independently of the quality of substrate. The dosage can be as high as several or even over a dozen per cent of substrate’s weight. What is expected is the increase in yield of the second and third flushes with maintaining of high volume weight of fruiting bodies in all flushes and maintaining of previous spread in consequential flushes.
  2. Elimination of thermal effect after placing on the shelf and during the growth, mainly between the first and the second flushes. In case of low activity, starch supplements could be introduced.
  3. Elimination of threats as green mould in the third flush by using feeding supplements to casing soil, that would be fully assimilated by mycelium until the end of shock and are not colonised by green mould after lowering of pH in casing soil during the third flush.

Cellulose supplements introduced to substrate are used by Agaricus as a source of glucose in the process of external enzymatic degradation. This process is most effective in temperatures of 23-270 C, so in temperatures in which the growth of mycelium is the quickest. Exceeding temperature of 300 C stops the process nearly completely. Controlling the temperature may be easier because of high water capacity of these supplements. As a result thermal effect is eliminated. This effect was the main reason of reduction of possibilities of using high dosages of available nowadays supplements with high protein content. They are the cause of increase of temperatures, which obstructs usage of cellulose and hemicellulose it is containing. Usage of which decreases when the temperature of substrate is higher than 270 C. Initial increase of substrate’s temperature after being placed on the shelf can be fully controlled by using higher dosages of water. Higher water capacity of substrate that is enriched that way makes controlling the temperature easier. The beginning of increase of temperature signifies the moment of starting of assimilation of glucose from feeding supplement introduced into substrate.

Additional factor that can stabilise the yield is usage of the feeding supplement in the casing soil. The requirements are similar as to using feeding supplements in the substrate. Recommendations which are to be followed to effectively use supplement to Nutrigain casing soil can be an example of this. After introduction to the casing soil with the last two litres of water, it is to be covered by micro perforated foil. The air flow should be reduced, so the temperature of casing soil is high enough. Covering it allows high concentration of carbon dioxide to occur, which benefits enzymatic activity of the mycelium.

Goals of using cellulose feeding supplements that were mentioned above are to be reached without the raise of cost (or in very small increase), because raw materials used in their productions are cheaper, and also the cultivation process can be done on a smaller amount of substrate.

If the compost producer doesn’t provide services of putting the feeding supplement into the compost projected goals can be achieved by self-determination of the dose of feeding supplement and putting it into the substrate in a mushroom farm during placement of the shelves. In smaller companies the dosages could be established based on the individual check of the quality of compost and will take into consideration using excessive amount of feeding supplements over the projected yield volume. Bigger mushrooms farms can establish the dosages and recipes based on the actual needs, using mobile NIR spectrometer that allows checking substrate’s quality during loading.

Is this solution a real one?

Using cellulose supplements seems to be a real solution of problems with standardisation of quality of substrate, but is it really? And to what extent? Also can it be implemented in all kinds of substrates that are produced in Poland? To answer those questions several tests in production context have to be conducted. Results of first tests show, that there is a high probability of achieving this goal.

One can assume this solution has potential for real changes, because it is based on solid scientific knowledge.

For mushrooms the straw in compost is the basic source of glucose, assimilated from cellulose and hemicellulose in it. Their placement is the problem. They are in cell walls surrounded by lignin, which is not digested effectively by Agaricus’ enzymes (in contrast to Pleurotus, which has this ability and so can be grown on straw itself). For mushrooms to have access to glucose straw has to be submitted to the process of composting or to be mechanically teared. It is shown on illustration number 1.

Raw materials used in production of feeding supplements are usually wastes occurring during agricultural production or are cheaper than wheat seeds or soya. But they need additional processing: grinding and tearing of cell membranes (extrusion, expanding or micronization). The process of tearing the membranes allows for sanitization of supplement (getting rid of potentially harmful microflora), at the same time those processes have to be done properly, as not to allow for substances that limit mycelium’s activity to occur.

Processing of raw materials causes significant increase in feed supplement’s water volume and easier humidity and as a result, increases in assimilation of nutrients that are in it. Giving mushrooms source of nitrogen, which is obtained by enzymatic decomposition of proteins, is significant too. Cellulose feeding supplements have got some amount of proteins and other components essential for mushroom’s life. Those contents are located in dead cytoplasm of cells of plants used as raw material for their production. There are also micro- and macro elements essential for mushrooms life in feeding supplements, but in case of lack of them they can be supplemented using TOP Vital. Its composition can be matched according to current needs.

Achieving positive results during conducted test will depend on development of technology of using high dosages of cellulose feeding supplements. On one hand the development should influence placing and correct mixing with substrate, on the other hand – balancing the dosages of water.

Other tests are also conducted on dividing the dosages of feeding supplement, when it is put in a part of phase II substrate. However using this solution is limited because of the humidity of the compost. Dosages that are too high may lead to deficit of water, at the same time limiting its usefulness. Feeding supplement implementing goals, that were mentioned above is produces by company Aril. (Photo 1 and 2)

Developing technology, which would allow increase in high quality yield and reduction of production costs, are significant factors in maintaining competitiveness of mushrooms produced in Poland.

 

Photo. 1. New product

Photo. 2. Previous product

Illustration. 1 Processed lignin-cellulose fibre

Source: based on: L. Kratky, T. Jirout, Biomass size reduction machines for enhancing biogas

production, „Chemical Engineering&Technology” 2011 no. 34, p. 391-399. Cited in: Kamil Witaszek, Agnieszka Anna Pilarska, Krzysztof Pilarski, Wybrane metody wstępnej obróbki surowców roślinnych stosowanych do produkcji biogazu, „Ekonomia i Środowisko” 2 (53), 2015, p.130-144

 

Polska wersja artykułu / Polish version

NEW: What about 40kg/m2

Biuletyn producenta Pieczarek PIECZARKI 3/2017  S. 28-32

What about 40kg/m2

dr Nikodem Sakson, Poznań

During the Pieczarkalia Mushroom Festival in 2014 a concept of developing the technology of production of mushrooms on fresh market was presented. The goal was to reach the average yearly level of yield of 40 kg/m2 in three flushes. At the time of formulating this goal a yield of 32 kg/m2 in three flushes on phase III substrate with the average amount of 85 kg/m2 with 1,5% of protein supplement in one dose was considered good enough both in Poland and in Netherlands. This issue of Bulletin is supposed to be published after Pieczarkalia 2017. It is a good moment to present the results achieved from implementing changes in technology and further perspectives of its development.

Searching for a cost-free increase in yield is the result of the fact that the prices of mushrooms have been constant for several years. Despite the increase of production costs, the prices that producers get from their clients are still the same. Increase in the yield without the increase in cost of production is the only way to maintain or improve profitability of mushroom cultivation in Poland. Both several percent increase of consumption of mushrooms in Poland and 2% increase in Europe haven’t changed this situation.

Presentation of the concept of technology that would allow achieving yield on level of 40 kg/m2 during Pieczarkalia 2014 was accompanied by amusement and ridicule, which were the result of the fact, that this goal was considered unrealistic in situation when Dutch producers didn’t improve their technology and didn’t increase their level of yield. A good reception of this concept wasn’t helped by the fact that I connected it with a question whether it is possible to produce mushrooms without traditionally produced substrate. Also intention of using starch feeding supplement (based on grains of wheat, mainly corn), is against the interest of several companies specialising in supply of materials to mushroom farms. These are not factors that would work in favour of good reception of Authors actions.

Describing the state of this technology, three questions have to be answered.

What was achieved thanks to implementing changes into the technology of mushroom growth and what changes where implemented?

In 2016 on a total area of 16 000 m2 an average yearly yield of 36 kg/m2 was achieved in three flushes of mushrooms for a fresh market. On every mushroom farm the yield of 40 kg/m2 was exceeded several times during the year. Here I would like to thank those, who took a risk in verification of proposed changes in technology – Mushroom Farm Chełkowscy, especially Mariusz Chełkowski and Zbigniew Marczak, and company Aril, especially Dorota Chmielewska, who took on producing feeding supplements. Without their involvement, those results could not be achieved. They were achieved by implementing following technological changes:

  • using Aril feeding supplement to substrate and casing soil in dosages – to substrate – up to 2,7%, and 150 g/m2 to casing soil,
  • high dosages of water to substrate without any spills were used,
  • controlling the thermal effect,
  • controlling evapotranspiration, by its measurement, using Piche’s evaporimeter in one case, and water deficit in the second (absolute humidity with high level of changes of carbon dioxide and maintaining minimal air flow and system of watering the flooring),
  • substrate’s activity between flushes was minimalised, maintaining constant difference of temperature between the substrate and air for the whole period of yielding,
  • controlling the spread of the flush and density of fruiting bodies, using mentioned above systems of controlling evapotranspiration
  • controlling the volume weight of fruiting bodies, using the controlled evapotranspiration during cultivation,
  • losses caused by diseases and vermin were eliminated

All of the topics were the subject of publications in Bulletin.

Is the goal realistic?

The goal of achieving yearly average yield of 40 kg/m2 in three flushes can be considered a realistic one. Both in Poland and abroad the yield above 40 kg/m2 was achieved sporadically. We want to achieve the same goal using different kind of feeding supplements by company Nutrigain. The results of the last tests indicate that there is a possibility to achieve the level of yield reaching 45 kg/m2.

What is next?

Further increase of yield over 36 kg/m2 is connected to solving the problem with maintaining maximum volume weight of fruiting bodies during the whole yield of all the flushes and increasing yield in the third flush. At this moment it is impossible to increase the yield in the first and the second flush by increasing the number of fruiting bodies. The reason for this is that – because of limited number of workers for picking mushrooms and because of the increasing cost of picking – the only acceptable solution is not allowing for too many buds to bind. There is a necessity of spreading the flush by manually removing the excess of small fruiting bodies. The heavier the fruiting bodies, the bigger the harvesting efficiency is. The volume mass and the ability to maintain it after the harvest depends on the number of cells in the fruiting body and on constant accessibility to water. The bigger the number of cells, the higher the volume weight and the longer it is maintained after the harvest. The fruiting bodies can be heavier too, if one can introduce water between the space of the cells (stopping the evaporation), but the quality and durability of those fruiting bodies is low.

The number of cells depends on accessibility of nutrients in the mycelium and their transport and accessibility of micro- and macro elements which regulate the process of using carbohydrates, mushroom’s main building material and its source of energy. The tests with TOP VITAL 7 and TOP VITAL 8 are conducted to reach those goals. They should allow increasing the level of yield for minimum 5% or more and stabilizing them.

Transportation of nutrients is a significant setback in maintaining high volume weight of fruiting bodies, especially in the second and the third flushes. That is why we were trying to achieve different arrangement of nutrients in casing soil and substrate underneath, so the transport would be the shortest. Answering the question whether this assumption is true or not is limited because of lack of technological possibilities of this kind of arrangement of feeding supplement in substrate.

Another issue is the question why can such different yield on substrate from its different batches and from different producers occur? I will return to this question in the next issue of Bulletin.

There is still lack of progress in increasing the yield in third and sequential flushes. The problem occurs because mushrooms feed using the different method at this period. In this flush Agaricus uses the nutrients that were dissolved in the water, and were produced by microorganism that continue the process of cold composting of the substrate. At the moment there are no possibilities of testing the solutions to this problem. Maybe a supplement to a phase III substrate, especially prepared used substrate after cultivation, can be a solution.

Improvement of availability of nutrients, leads us to search for races of mushrooms with a higher nutritional requirements, which would give higher yield. There are no typical races of group U-1 mycelium on the market. Only races that are similar to this group like E-58 Premium, VIP, Magnum, or Triplex are available. They are still waiting for their place in the mass production. To achieve this, substrate containing those races should be delivered only to this producers, who are able to provide them with required conditions.

An issue that wasn’t solved in a satisfactory way is the danger of green mould occurring, caused by Penicilium mushrooms in the third flush. The result of which is development of buds on fruiting bodies in a form of brown spots. Jos Hilkens in the issue 39 (20017) of “Mushroom Business” as a cause of this problem considers: “(…) the remains of the mushrooms, underdeveloped or dead parts of susbtrate, sometimes feeding supplements, which get into substrate from casing soil by CACing, or are deliberately placed in the casing soil.” When spots of green mould occur on a casing soil it is necessary to isolate them by covering them with paper towels dipped in a solution of disinfectant. It is recommended that the concentration of carbon dioxide is very low, about 500-600 p. p. m. during the period between the ends of harvest of the second flush till the beginning of harvest of the third flush. Creating such conditions isn’t hard, taking into consideration low activity of substrate which is the cause of small production of carbon dioxide in this period. It is necessary to control the weight of the fruiting bodies, the activity of substrate and to match the level of evapotranspiration to these conditions by regulating relative humidity. We are searching for other forms of feeding supplement used for casing soil, and we block the movement of pins of Penicilium with water or air, protecting from losses that result in development of green mould on a surface of casing soil. Another solution can be resigning from harvesting the third flush and concentration on achieving level of yield of 18 kg/m2 in the first and second flush, so limiting the goal to 36 kg/m2 with using feeding supplement in casing soil.

The effect of proposed technology is higher usage of starch feeding supplements in the last months. It allows reducing the cost of production, which is especially noticeable on big mushroom farms.

Photo. 1. Tests with liquid feeding supplement to the casing soil – high shelf.

Photo. 2. Tests with drip irrigation on the whole cultivation area.

Fot. 3. Another tests with vermiculite

Polska wersja artykułu / Polish version

NEW: Is the production of compost and substrate a black box?

Biuletyn producenta Pieczarek PIECZARKI 1/2017  S. 21-31

Is the production of compost and substrate a black box?

dr Nikodem Sakson, Poznań

To have high and stable yield of mushrooms one needs stable and high quality substrate used during the cultivation process. Analysing cultivations in mushroom farms, which had average yearly yield on a fresh market (in 2016) of 36 kg/m2, a question was asked, how can substrate, casing soil and mycelium influence the yield on sequential projections. In case of substrate, average yearly yield could be higher for around 2-3 kg/m2, if used materials didn’t depart form the expected standards of quality. Decrease in yield was sometimes significant, reaching up to 7 kg/m2. It is to be expected that this year (2017) there will be great differentiation in yield and lower average yield than in 2016.

In case of casing soil and mycelium from the group of intermediate spawns, close to U-1, differences in yield were minimal. Those materials rather influenced the assortment of fruiting bodies and the quality then the average yield.  It means that – to have average yield on the level of 40 kg/m2 – one has to improve the stability of compost or (if the quality of substrate is far from standard) find the way of additional supplementation, which would improve the mass of mycelium in substrate between putting on the shelf to the end of the aeration.

This is the first reason, why in this article I would like to try to answer the question of sources of this variability, and also ask if there are some possibilities to improve quality and stability of substrate. Nowadays substrates with added to 1, 5% of protein feeding supplements allows to reach the maximum level of yield at 32-33 kg/m2. Without protein supplements the average yield would be lower at 2-3 kg. This means that in current production and growth systems we are able to deliver nutrients on a level of projected yield. Sporadically higher yield occur – reaching the level of even 40 kg/m2, but much lower yields also occur. Second reason for writing this article is the text by dr. K. Szudyga titled “The black box” that was published in “Pieczarka” Bulletin in issue 2/2017. The text was about production of compost and substrate.

The title alone gives an answer to the question – why the quality of compost and substrate in Poland is unstable. Their production is a proverbial black box. I am afraid that the meaning of the phrase “black box” would be unclear for the most of the readers that is why it needs some clarification. Searching on the Internet these words in Polish one can receive information, that this is a machine that registers flight’s details in planes, and recently in cars. But this doesn’t make it clearer. Only when searching for this phrase in English can we find an answer that can interest us. English Wikipedia writes: “In science, computing, and engineering, a black box is a device, system or object which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings.” This explains why the author of the article decided to use this phrase. We know what we put in (straw, chicken manure, gypsum, water, sometimes horse manure and urea) and we know what we get as a result (compost or substrate of specific features parameters), but we don’t know why this happens and how. In consequence to all these there is a tendency to assign a special role in compost yards to technological specialists, on whom the future of the whole market is supposedly dependent on. One can paraphrase a saying by Marek Ouden at this point, who stated that the production of materials for mushroom growth is more an art than science. This is why this author stresses the role of technology specialists in the process of production and the final result. It depends on their talent, experience, the sense of situation, involvement and on the fact whether they have an artistic flow on the given day or not. In this article one can find several information about achievements in the field of compost and substrate production, which are the basis of their technology of production nowadays. Descriptions of those achievements show, that the process of production is well documented scientifically and there is a problem in using this knowledge, and not in lack of it. It negates the dependence of character traits and involvement of technology specialists in compost yards, but doesn’t diminish their significance as people responsible for the process of production. Still the problem of black box is real, which can be exemplified by the fact that the basic process of producing compost is called alternately by two terms: “composting” and “fermentation”.

This shows significant chaos in the basic principles of knowledge about the process of compost production, because those terms and their way of working should negate each other. The term “composting” should be used only to describe the process of making compost (hot phase), always in oxygen conditions (availability of air). From the moment the mycelium is placed in the compost, we should use the word “substrate”, which contains mycelium and unused by it compost – organic matter, mineral compounds and microflora (mainly Scytalidium). Fermentation on the other hand is a process of achieving energy from dead organic matter by anaerobic microorganisms. It cannot be used to describe the process of production of compost. I too made the mistake of using this word in the past.

In this situation it is worth it to ask a question whether mentioned black box is a fact or a myth. The fact, that no system of controlling of technology of production of compost and substrate was developed based on the scientific knowledge about composting process with Agaricus, doesn’t allow us, in my opinion, to say that this process is a black box. To sum up – the main reason of changing quality of compost and substrate (apart from mistakes and technological failures) is lack of means to assess what and how much of it we use at the beginning and what – after mixing the materials – we should get as a result and what kind of characteristics should the substrate have. The technology itself allows achieving temporarily or sporadically high quality compost and substrate for mushrooms production, which means there are possibilities of improvement of their stability and quality.

Scientific knowledge gives us information: what should we put in (what materials to use), how does the process of production of compost and its colonization proceed, and what should we get out of it, or what kind of substrate we are expecting end eventually, how to enrich it, to achieve expected yield.

What don’t we know? What in reality we are putting in and what we get as a result, what is the yielding potential of the substrate offered for sale and how can we enrich the compost and substrate. It is a result of lack of information about what kind of characteristics can we measure and how to correct the process of production based on a system of control of materials, compost in sequential phases, and substrate.

In this situation it is worth to answer the question what conditions have to be fulfilled, for the composting process to undergo correctly and what kind of expectations from the compost and substrate can we have, taking into consideration the expected level of yield. The last question is “why”?

The main reason that is stopping the development of technology and minimalizing changing quality is a lack of connection between used technology and the nutrient needs of mushrooms. Division of the process of production of compost from the cultivation of mushrooms only deepens the divide. In companies, where such connection exists, there is a lack of tools for interpretation of characteristics of compost in comparison to achieved yield.

Introduction into the control system of new methods of analysing the characteristics of compost (NIR – spectroscopy with short range infrared) didn’t change the situation. Polish compost yards, which use this analytical system, do not produce substrate of better quality and stability.

What is next?

Improvement of production of compost and substrate should be based on scientific knowledge about the nutrition of Agaricus, and also on methods of analysis based on NIR adopted (and further developed) from feed industry, taking into consideration nutritional needs of mushrooms. Following factors should be considered:

  1. Planes are the natural habitat of Agaricus. Places where grass dominates undergo decomposition after dying, mineralization and humification (composting). This means that Agaricus, as a saprobiont is best adjusted to use dead organic waste originating from grass.
  2. What is it feeding on? Mushrooms feed during the enzymatic decomposition process (biodegradation, bioconversion and biosynthesis) of dead cell membranes (CWC) containing hemicellulose, cellulose, lignin, pectin, cut in, wax and silicon) and dead content of insides of cells (CC) containing soluble proteins, fats, non-protein nitrogen, amides, organic acids, soluble sugars, starch, pectin, mineral contents, glucosides, alkaloids and tannin) of grass and dead microorganisms and dissolved in water basic sugars and mineral content, that are delivered by decomposition of biomass, that are released in mineralization process by microorganisms that are in the vicinity. The basic mechanism of decomposition of cellular membranes and insides of the cells (cytoplasm) is external enzymatic decomposition. Its main function is to get glucose (mainly cellulose and hemicellulose), which is used to get energy necessary for sustaining life functions, It is al used as a building material, by transforming it into polysaccharide chitin (glucose + nitrogen, mainly dissolved in water NH4+, a result of ammonification process), used in development of mycelium and later of a fruiting body. In mushroom cultivation lignin is used very rarely. It is a part of substrates construction, which gives it a structure. If quick decomposition of lignin occurred, the substrate wouldn’t have the structure needed for the yield that would allow for gas exchange and water volume. Agaricus doesn’t have the ability to use the amino acids directly. It synthesises its own amino acids and other contents of cytoplasm by itself. The feeding process can be disrupted by contents called inhibitors of Agaricus enzymes. But this is a different issue.
  3. What is a level of yield of mushrooms dependent on?

The yield of mushrooms in the first and second flushes depends on the mass of mycelium in the substrate and casing soil, in the third and sequential flushes – it depends on availability of nutrients released by microorganism that are in the substrate, mainly Scytalidium.

  1. What process do we use for compost production and what is the connection with the way the mushrooms behave? Composting process is the base, and in mushroom production we use a part of it called mineralization process, which is decomposition of complex dead organic matter by enzymes of microorganisms into simpler inorganic (biodegradation) and organic (bioconversion) compounds and non-enzymatic decomposition of organic matter in Mallards’ process (caramelization). The basis for composting of dead organic matter is its content, which provides the 30 to 1 carbon to nitrogen ratio (the composting process starts which much higher ratio of C to N, 17-30 : 1) and water and phosphorus to carbon ratio as 100 : 1 in condition of availability of oxygen. The source of nitrogen is uric acid from chicken manure and horse urine (when using horse manure). During the production of compost to grow mushrooms we use the first phase of composting process, called the hot phase, during which biodegradation of straw takes place, which means its opening (biodegradation of wax) and defibration (biodegradation of pectin). For the digestibility of cellular membranes to be higher, higher access to the insides of cells, increased water volume of compost and the process of ammonification are needed. Those processes are done by mesophilic microorganism. Further increase of temperature is done by thermophilic organisms, which further the process of straw’s biodegradation. After reaching the temperature of above 75oC non-enzymatic process of transformation of sugars and proteins in high temperatures begin (caramelization), which delivers nutrients to the developing microflora in the process of maturing and sanitization (pasteurization). Elimination of adverse for the process microorganisms during the so called “cold composting” phase (mineralization of compost by mushrooms) also takes place. This stage can be described as preparation of nutritional base for microorganism multiplied during the maturing process and releasing of ammonia (volatile nitrogen). However ammonia is the source of loss of nitrogen during the composting process. This is why it is so important to aerate the prisms, when the release of ammonia is too high. Loss of nitrogen can also happen when there are anaerobic zones in the compost. Then the process of denitrification starts, meaning transformation of nitrates into gas forms of nitrogen. Another undesirable process is the loss of carbon in the process of too intense mineralization (it is caused by the mineralization process taking too long or by maintaining too high temperatures of compost for too long). Composting process is exothermically, in which polysaccharides are transformed into energy, and at the same time there is a decrease of their amount, so they are not available for microflora during the maturity process and for mushrooms during the phase of compost’s hypertrophy. Observations indicate that there is a necessity of adjusting the high temperatures phase to the hardness of the straw. During the same schemata of production we can achieve very different results. The differences occur especially in the amount of nutrients for mushrooms in the compost. Compost made of soft straw can be very easily made with too much decrease of carbon, cellulose and hemicellulose content. After thermophilic microorganisms use easily accessed sugars and nitrogen, the temperature lowers, thermophilic microorganisms die (phase II). The result is a biomass, contents of which are partaking in the maturity process of dead cells of microorganism and not mineralized organic matter. The progress of biochemical processes that take place in the compost is well known. Sown mycelium, after colonization of the compost (eliminating adverse microorganisms and unnecessary for its development, leaving only Scytalidium) will use the nutrients by enzymatic digestion and builds mycelium in the biosynthesis process. Cellulose leftover after the shock is still digested, mainly by Scytalidium. Simple sugars and mineral content that were dissolved in water are used by mushrooms, mainly in the third and sequential flushes.

In case of mushroom cultivation the humification process starts after introduction of substrate into soil after hypertrophy. It take place by decomposition of not mineralized straw of the harder to dissolve polysaccharides, mainly lignin, by soil organisms and its transformation into caries that is enriched by mineral contents that were made in the process of mineralization.

Application of physical analytical methods in production of compost and substrate

Using analytical methods using NIR (close infrared spectroscopy)

For quick analysis of compost, also phase III compost and chicken manure and straw, one can purchase in Poland laboratory equipment offered by Mc Substradd. It contains analyser with according programming and data base. Measurement method is indirect and needs calibration, which means determining connection between the spectrum and compost. Producer offers such calibration, but it is necessary to adjust the readings to the conditions of specific compost yard. Buying such equipment doesn’t mean getting rid of a laboratory that is working with previously used wet methods, because there is a necessity of doing measurements supporting the calibration. NIR doesn’t denote the micro- and macro elements. The main advantage, because of which it is used nowadays, is simplicity and quickness of the analysis process. To get correct results a representative sample of analysed material is needed. Because of possibility of doing a lot of analyses in a short period of time it is possible to characterise compost in more precise way. However those are still the results after getting a sample, and not done in real time. Similar solutions are offered in Poland by Nuscana Biotechnika Laboratoryjna. This company offers, apart from NIR, calibration to specific needs of compost producers. The advantage is that the tests and calibrations are made in Poland, and the calibrations are free. Making the tests with classical methods is the only cost here. Calibrations curves are created by using the laboratory tests and spectrum of samples, and are then installed into the NIR. Those calibrations can be widened and improved upon by adding additional points. One can add new characteristics to existing methods. Companies that have their own laboratory are equipped by Nuscana with programs for calibration. They offer training courses too.

Following parameters of compost and correlations between them can be used (from McSubstradd):

  • humidity,
  • raw proteins,

General proteins, raw proteins – whole amount of nitrogen based nutrients, which means proper proteins, complex proteins and non-protein nitrogen compounds (NPN), which have nitrogen in their content.

  • pH,
  • ash
  • general volatile nitrogen (TVN)
  • ADF cellulose
  • NDF hemicellulose
  • ADL lignin

The following words from the website characterize the way to understand the meaning of tested parameters in compost production: “By the last three parameters we can characterize the content of carbohydrates in compost, one of the main sources of nutrition for mycelium. Composting as a process is based on decomposition of carbohydrates and making them with organic nitrogen available for mycelium. Analysing this is a step forward.” It is hard to agree with the statement that Agaricus is directly using organic nitrogen. Scientific knowledge doesn’t confirm that.

Chicken manure

In chicken manure one can measure humidity, ash, nitrogen and ammonia.

Straw

NIR allows measuring its structure, water volume, and nutritional level.

There is no information on possibilities of measuring the content of liquid manure.

Process of production of compost and substrate and a range of analysis done on it

Here is a proposal for analysis program during the process of production of compost and substrate:

  1. Analysis of raw materials;
  • Chicken manure: humidity, ash, nitrogen and ammonia, NSP (biomass), NDF (hemicellulose), ADF (cellulose) and NPN (non-protein nitrogen);
  • Straw: structure, water volume, and nutritional level and pectin and waxes;
  • Liquid manure: nitrogen content, pH, RD;

Another open issue is the question if raw materials have contents that disrupt the composting process, and if yes what are they and how to measure them?

  1. Phase I compost;
  • determining the recipe according to previous analysis; Determining the C: N recipe taking into consideration the losses that are the result of release of ammonia. This is, at this moment, the hardest element of the technology. Determining and achieving the right ratio of C : N is the basic condition of achieving stable compost. Type and state of chicken manure, besides the correct weight of the raw materials, is the biggest challenge. The ratio of carbon to phosphorus (C: P) has to be controlled also, using wet analysis.
  • mixing the materials.

After mixing the materials: humidity, NSP (biomass) and NPN (non-protein nitrogen), C: P, C: N (according to previously determined standard);

  • mesophilic phase – opening and defibration of straw, building in water, beginning of nitrification process in aeration conditions;

The level of content of wax and pectin should be an indication of the level of opening of straw.

  • biochemical thermophilic phase with aeration, multiplication of thermophilic microorganisms and caramelization process;

Measuring NFC (non-structural sugars) and NPN (non-protein nitrogen), apart from standard measurements for compost;

  1. Phase II compost

The goal of this phase of compost production is maximal accumulation of biomass from dead microorganisms, hemicellulose, and cellulose and non-protein nitrogen. Their level indicates nutritional potential that are assimilated by mycelium during the enzymatic distribution. After the end of pasteurisation, maturing and cooling of compost standard analysis should be made, the same as in phase 1 compost and also: NSP (biomass), NPN (non-protein nitrogen), NDF (hemicellulose), ADF (cellulose) and NFC (non-structural sugars can indicate the possibility of growth of green mould).

  1. Substrate (phase III)

The effect of this phase is achieving the maximum transfer of nutrients that are assimilated by mushrooms into the mycelium. After the compost hypertrophy – the analysis spectrum the same as for phase II compost, measurement of mycelium’s mass by marking organic nitrogen as indirect indication (mycelium+ Scytalidium), and NSP (biomass), NPN (non-protein nitrogen), NDF (hemicellulose), ADF (cellulose) and NFC (non-structural sugars), which will show the potential of yield of the third flush that is in the compost, nutrients for Scytalidium.

The basics of controlling the process of production of compost and substrate

Production of substrate of stable quality allowing for the yield to achieve the level of 40 kg/m2 is possible by doing the following tasks in order:

  1. Rating the state of raw materials,
  2. Working out the recipe,
  3. Mixing the materials,
  4. Executing the biodegradation of straw with mesophilic and thermophilic microorganisms,
  5. Executing caramelization process of mixture of materials in Mallard’s process,
  6. Rating the production process of phase I substrate and deciding whether to use supplement of nutrient, up to the accepted standard,
  7. Executing pasteurization and conditioning,
  8. Rating the production process of phase II substrate deciding whether to use supplement of nutrient, up to the accepted standard,
  9. Sowing of mycelium and executing substrate’s hypertrophy,
  10. Rating the process of hypertrophy and substrate and deciding whether to use supplement of nutrient up to the accepted standard, or passing recommendations to mushroom growers about eventual supplementation program.

The key is determining the C: N ratio at the start, rating the level of straws defibration and the release of carbohydrates and the level of transformation of organic matter into useful microflora and straw for the mushrooms’ enzymatic decomposition.

Implementation

The implementation process needs time and a lot of intellectual and organizational work in compost yard, and also cooperation with clients.

It can be divided into the following phases:

  1. Implementation of measuring procedures and verification of company’s standards (calibration) and accepting different concept of rating of compost and substrate;
  2. Building company’s own data base integrating achieved results and information about the way substrate behaves when clients get it, and also abilities for analysis of received information and abilities to draw conclusions to use it in potential changes in technology;
  3. Controlling the production phases based on the results of analysis and observation;
  4. Deciding whether to use supplements and feeding supplements or not, at what scale and doing trial tests before integrating them into production of compost and substrate.

What are the main reasons for changes in the quality of substrate nowadays?

  1. Uncontrolled process of straw’s decomposition after mixing the materials. The yield is much lower, if the level of opening of straw is smaller. The indication of this state is higher amount of waxes, mainly pectin. It results in a smaller content of sugars available in the maturing phase in the caramelization phase and lower availability of hemicellulose and cellulose to microorganisms during the maturity phase. As an effect the availability of biomass form mushrooms is lower.
  2. Too low availability of non-protein nitrogen during the whole process of compost production. It is a result of high differences of amino acids in chicken manure, and that it is evaporating easily in the process of ammonification. Scarcity of non-protein nitrogen restricts the creation of biomass in phase II and limits the possibility of using the glucose obtained in the process of enzymatic digestion by Agaricus, and as a result it limits its ability to create chitin and proteins.
  3. High loss of carbon in crumbly straw by using the same technological cycles. This is probably the main reason of decrease of yield level in the second flush.

Expected level of abundance of substrate allowing for a yield of 40kg/m2 in three flushes on fresh market can be achieved by its production in compost yards or by supplementing on mushroom farm. Right now demand for this kind of product is not high, because not many producers of mushrooms can achieve such yield. What is left in this situation is to find such supplements and feeding supplements, which would meet those expectations, independently of the quality of the produced substrate. Can those expectations be met? I think so. The basis of those feeding supplements should be cellulose supplements enriched in micro- and macro elements without causing thermal effect. It would allow using them in high dosages, so it would be always possible to achieve expected yield. First tests show that those assumptions are correct.

Polska wersja artykułu / Polish version

TECHNOLOGY OF GROWTH AND NUTRITION OF MUSHROOMS

Biuletyn Producenta Pieczarek PIECZARKI 1\2016 p.12-18

After presenting in the last two numbers of the Biuletyn the knowledge about the processes of nutrition of mushrooms and ways of controlling it one can present its current use in cultivation. This knowledge is the result of many cultivation tests and observations of the behavior of the mushrooms made in the last two years. The aim of the changes in technology is to obtain stable yields of 40 kg/ m2 in three flushes in each growing cycle. Periodic achieving of such yields does not transfer, so far, on the yield of mushrooms at this level throughout the year. It faces a number of constraints. The first group is the variability of the qualities of raw materials, mainly compost. The second – controlling the evapotranspiration, or evaporation from the surface of the spawn and fruiting bodies, the casing soil and the compost, and also transportation of the water from the compost to fruiting bodies. This is a result both of incomplete knowledge of these processes, and deficiencies in the technical equipment allowing to control the microclimate in the cultivation room, which would be able to ensure the provision of maximum volume weight of fruiting bodies throughout the harvesting season.

Today, we can point to several conditions that must be taken into account for it to be possible to obtain high and stable yields. To most important of them are included in the following statements:

  • Potential yield that can be obtained is dependent upon the weight of the spawn and the permanent access to water in the casing soil and the compost throughout the cultivation period. This means it is necessary to collect and supplement them in water, according to the weight of the spawn, and managing water in such way, not to allow its deficit during the whole cultivation period.
  • Maintaining gas exchange between the ground and the air in the cultivation room is required through the casing soil for the entire cultivation period.
  • Thermal effect has to be controlled (temperature rise above 25°C) after application of the compost and the start of the shock and between the first and the second flush. An excessive increase in temperature normally prevents control of the fruiting bodies due to their excessive transpiration, while too rapid evaporation of the casing soil interrupts water flow from the compost and results in drying. At present it is not fully known how to change relations between evaporation and transpiration with increasing temperature of the compost and, how to influence the transpiration, for it not to be too high, and therefore not to be followed by a significant decrease in the weight of harvested fruiting bodies. All indications point that the correct procedure is to prevent exceeding of the temperature in the ground above 26°C, and not only to control transpiration in this period.

Lack of increase in temperature of the compost between the flushes has also a beneficial effect on controlling the amount of pins in the second flush.

  • During the shock the resource of created pins allows to obtain a yield of 172 kg\ m2. This means that each time one has to provide the required number of fruiting bodies necessary to achieve the target level of yield. The number of fruiting bodies and generations depends on the conditions the pins have during cultivation.

Controlling the number of fruiting bodies and generations is based on the release of pins after shock in each flush. The release of pins takes place every second day from the middle of the harvest, and is controlled by maintaining the evaporation levels from the surface of the shelf ensuring their growth.

  • The yield depends not only on the number of harvested fruiting bodies, but also on their volume weight during the harvest of all the flushes. The aim should be to ensure that those levels are maximized. But they are not constant. Our observations indicate a decrease in the maximum weight of fruiting bodies with every next flush. In the first flush the weight of the fruiting body of a diameter of 5-5.5 cm and of 60-65 g can be sustained, in the second – 45-50 g, and the third – 40 g. Probable cause of weight loss in the several flushes are initially – insufficient water in the compost and the casing soil, followed by – decrease of nutrients supplied to the fruiting bodies because of the increasing duration of their transport from the spawn in the compost. It is not impossible that in the future one will be able to obtain the same maximum weights volume in each flush.

In order to achieve the maximum weight of the fruiting body, the use of calcium chloride should be considered expedient and controlling the salinity of the casing soil, so that it was not too low. It is important to water the fruiting bodies during harvesting as the loaded compost was very dry.

  • Only selective collection can ensure that one can get the maximum weight of each fruiting body.
  • The occurrence of diseases and pests may significantly reduce the yield obtained.

Materials

The potential level of yield of mushrooms is determined mainly by the characteristics of the compost, casing soil and applied feeding supplements.

  • Variability of the ground, which took place in the past year, allows to identify those of them that may impact the process of nutrition. Highlights include:
  • Water capacity of the compost. It is the ability to retain water after hypertrophy of mushroom’s spawn. Determining water capacity is simple and can be performed independently. It ranges from 200 to 500 g per 1kg of Phase III compost. This means that the dose of the compost 85 kg/m2 can absorb from 17 to 42,5 l/m2 of water. This also explains why at the same dosage of water to the compost, sometimes it is leaking in large quantities and sometimes there is too little water, and thus the compost does not have the appropriate resource to maintain the expected level of yield and to maintain the cooling effect. Is it possible to stabilize the water capacity of compost? Such capabilities are tested and it seems quite likely that one will be able to correct it by adding crafted hemicellulose.
  • Highly diverse activity of the compost as a result of the variable nitrogen content and the degree of controlling it by the spawn. The high nitrogen content in conjunction with additives and feeding supplements induces the thermal effect. Short hypertrophy means reduced movement of nutrients to the spawn thereby reducing the potential yield. It also promotes greater proliferation of thermophilic organisms, as they are less controlled by the mushroom’s spawn.
  • The casing soil. It is designed to ensure a good exchange of gas between the compost and the air in the cultivation room and soaking water from the compost. Therefore casing soil with a very good and durable structure and large water capacity is the best. But its behavior in the cultivation room has been significantly affected by its application and treatment after applying, mainly rolling and watering. The casing soil may not have anaerobic zones. Combing is treated as the need to correct its structure (its restoration) after an intensive watering. Watering by the so called tree usually makes it worse when applying high doses of water, watering under shelves allows to maintain the structure without combing at the same high doses of water.
  • Feeding supplements. Currently, the basic feeding supplement added to the compost is appropriately chosen, dried and grinded corn seeds. Granulation is their important feature. If the granules are very small a significant temperature rise in the compost can be observed, on the other hand when the granules are too thick it reduces their bioavailability. It is visible when emptying the shelves after end of cultivation. The impact of feeding supplements on the behavior of the spawn is presented on photo. 1 and 2.

 

Casing soil before the shock and after using feeding supplements
Casing soil before the shock and after using feeding supplements

 

Casing soil before the shock without feeding supplement.
Casing soil before the shock without feeding supplement.

 

Technical equipment.

Currently existing equipment is used. Evaporation process is more easily controlled if one can maintain the required level of temperature, relative humidity, at the lowest, equal movement of air in the cultivation room. Currently used air conditioners have limited ability to meet this condition. This implies the need of designing the new generation that will be able to fully implement these principles.

  • Humidification system should be efficient and operate without condensation of water in the sleeve. Its efficiency can be improved by installing additional humidification systems: through the floor and under the shelves. While increasing humidity they are used in the first place, and only then – for the humidification of air.
  • The film under the compost should be perforated, which ensures the flow of excess water without accumulation at the bottom of the shelf.
  • Having a strain gauge installed in the casing soil makes it easier to control the flow of water to casing.
  • Piche’s evaporometer (Fig. 3) makes it easier to control the actual evaporation, evapotranspiration, although not yet fully able to control the behavior of the fruiting bodies of the assumed size of evaporation.
Piche's evaporometer
Piche’s evaporometer

 

It is also necessary to have well-functioning controllers of microclimate and knowledge of their functioning. This is due to the fact that the process of evapotranspiration (evaporation from mushrooms and casing soil) is the most easily adjusted when one can separately affect each desired parameter of the microclimate in the cultivation room.

The issue of equipping mushroom growers with devices allowing to control the process of cultivation is becoming an important rooming in the future.

What changes can be proposed to introduce to the current technology?

Below are the changes made on a production scale by the few mushroom growers.

  • Feeding supplement’s dose of corn to the compost – 2.5 kg evenly mixed with the compost.
  • Dose of feeding supplement added to casing soil – 200-300g /m2 evenly mixed with casing soil with a significant dose reduction of caking.
  • Compost evenly overlapped by 1-2 cm lifting in the roller of combine in a dose of 80-85 kg/m2.
  • Pouring water into the ground and casing soil.

Treatment, which we use, is pouring water into the compost by developed principles. Here is the most commonly used procedure: allow the water to the compost to pour after 24 hours from application, and after reaching the temperature of compost of 23-25°C the spawn’s growth starts. Basic dose, up to 45l/m2, is poured in the course of three days (at the time of the application). The first dose is 12l/m2 on the first day of watering, in the second – 16 l/m2, and in the third – the remaining or lower, if the compost was moist. A single dose of the water of 2 l/m2 poured at intervals of every two hours at lower compost temperatures. With increasing temperature interval are smaller and vary from one to one and a half hours when the temperature of compost is increasing. Water can seep through the compost. The purpose of this treatment is achieved when the compost temperature is stable and equals 23-25°C (up to maximum 27°C) with the air temperature of 18-19°C with moderate air movement on the fifth day from application of casing soil. This allows to start a mild shock. The following correlation is observed: the lower the compost temperature at the start of the shock, the less problems with overheating between the first and the second flush.

In case of a sharp rise in temperatures after the application of the compost and after pouring water, the temperature of the air in the growing room should be increasingly reduced with increasing air movement. In summer, one has to significantly increase the dose of water to stop the rise in temperatures in the compost. Sometimes this can result in the need for additional mixing fans. It is a tried, working procedure, but it requires adaptation to the conditions in the growing room.

 

  • performing shock when applying feeding supplements to casing soil, be aware of the tendency of intensified bonding. This is the result of more spawn in the casing soil and easier growth of pins after completion of shock. A very important procedure is the placement of generations. For this purpose, we traditionally use periodically reducing the temperature difference between the compost and the air. Reducing evaporation until it locks and controlling it using evaporometer, one can also temporarily pause the growth of next generations. Also, periodically raising the level of carbon dioxide to 10,000 p.p.m. may assist in this procedure.
  • Controlling the evaporation. The behavior of the mushrooms after getting shocked is dependable of the process of water evaporation from the surface of skin of pins and fruiting bodies. This process is called transpiration. The skin of mushrooms as compared to the plants is not capable of closing stomata, thus self-regulating this process. Transpiration depends mainly on the temperature of the air and ground, air movement and the content of water in it. The case would be simple if one could measure the process of transpiration. Such possibility doesn’t exist yet. So what can we measure? To track changes in potential evapotranspiration, we measure the relative humidity of the air or the water content in the air. Evapotranspiration is transpiration mushrooms, evaporation of water from the casing soil, floor and from any source of water in the room, for example, the one condensed in the sleeve. Relations between transpiration and evaporation of the remaining surfaces where there is water, vary. This explains why, at the same relative humidity and other parameters remaining the same in the microclimate, fruiting bodies behave differently – they are heavier or lighter, round, flat, and white or change color. For example, drying of the casing soil can cause that at the same relative humidity transpiration is greater, that is, there is a greater loss of water from the fruiting bodies that are lighter. We are trying to solve this problem by tracking evapotranspiration based on readings on the scale of Piche’s evaporometer. And then, only indirectly by observing the behavior of pins and fruiting bodies, the conditions are adjusted in the period of typically 12-hour or shorter, by controlling the volume of evaporation of mm of water column in evaporometer. It ranges from zero to several mm of water column. As the evaporation of the accepts standard five mm during 12 hours. In each mushroom farm it must be set individually, tracking the weight and appearance of the fruiting bodies in the period of harvesting and growth of each generation of pins. This method is more useful than the measurement of relative humidity, but it requires experience. Keep in mind that this method requires different approach to the parameters of microclimate. This was described in issue 2/2015 of the Biuletyn. Stabilization and increase of the yields of mushrooms. Cultivation from the end of the shock is carried out with the smallest possible movement of air (remember opening the flaps of fresh air and exhaust flap), a much greater range of carbon dioxide (2-10000 ppm), air temperature from 17-19°C, the activity of 2-3° The relative humidity, needed to maintain the expected evaporation, has got resulting value and can range from 100 to 80%.
  • As a rule we set selectively collection, gathering in real time information from the foragers about the weight (what is the current standard fruiting body weight) and the appearance of fruiting bodies (skin adhesion to the glove, shape of the fruiting bodies, do they become flat, and about their color, whether they are white or discolor begins). Depending on the situation, we perform correction of the evaporation – slow it down or accelerate by changes in air movement and relative humidity.

Technology of growth will continue to develop and often there will be reasons to discuss it.

Controlling the growth of mushrooms in conditions of nutrition

Biuletyn Producenta Pieczarek PIECZARKI 4/2015 s. 16-23

Providing mushrooms with resources needed for the expected yield, or the substratum and casing soil and sufficient quantity and weight of the spawn does not automatically mean the possibility of obtaining high yields, even if we have sufficient technical conditions to maintain microclimate conditions required for its growth and development. The wide variation in yields and not achieving their maximum size in relation to available resources is a fact. This means that we still do not really know how to control the behavior of the mushrooms. This is the second problem necessary to solve in order to achieve the intended objective of getting yields of 40 kg/m2 in three flushes. The issue of controlling the nutrition of mushrooms turned out to be much more difficult than expected at the time of acceding to build technology based on it. The current system of microclimate control in the cultivation hall turned out to be not fully useful to obtain stable yields and required development of new rules to ensure control of the behavior of mushrooms (in particular evaporation). Our knowledge about the causes of the variable behavior of the mushrooms during growth is also not full.

Controlling includes three major processes described below.

Recolonization of substratum after sowing feeding supplements. The purpose of controlling is to prevent hyperactive behavior of the substratum and to assimilate the mushrooms with introduced to the substratum feeding supplements. Achieving this goal is the first necessary condition to obtain the planned level of yield. Breakage of spawn in an overgrown substratum interferes achieved during growth balance between it and the thermophilic organisms (Scytalidium). This is due to the fact that – after breakage of the spawn and disengagement of the substratum during removal from the growth tunnel – between the straw there is more oxygen than before disengagement. Once incorporating therein a quantity of water necessary to balance the dose of feeding supplement, and as it has a high temperature, it causes multiplication of these organisms. This results in a rapid increase in heat and even faster proliferation of thermophilic organisms, while inhibiting the activity of mushroom spawn. If this rise is not interrupter before the temperature reaches over 32°C, it is life-threatening for spawn or significantly weakens it. Although the substratum is cooled intensely, by reducing the air temperature and increasing its movement, the balance between spawn and thermophilic organisms cannot be generally restored and to complete the second flush the cultivation is done over large temperature differences between air and substratum. This means that the shock is much more difficult to carry out and it is also hard to control transition to the second flush when the temperature of the substrate is high and tends to rise from the middle of the first flush. The fruiting bodies of the mushrooms are subjected to excessive evaporation of water from them, and thus the yield is reduced.

Please note that adding feeding supplements to the substratum requires an additional amount of water required in the digestion (broken spawn colonizes the substratum once again and digests the feeding supplement with enzymes until the end of the shock) and transportation of nutrients to the fruiting bodies. This requires the development of a program of pouring water into the substratum. This program is modified depending on the season, humidity and behavior of the compost.

Keep in mind that the cultivation of mushrooms on substratum with excessive activity requires a different approach to control its growth.

Transpiration – evaporation of water from the surface of the fruiting bodies, which determines the rate of their growth. The aim is to obtain the maximum weight while keeping the characteristics of fruiting bodies typical of the breed cultivated throughout the harvesting season. Mushroom do not have any slits in its rind, which means that the rate of evaporation of water from its surface (in accordance with the process of transportation of nutrients) depends mainly on the parameters of the microclimate and the temperature of substratum. Both too fast growth of the fruiting bodies and too slow worsen their welfare, its quality and weight. This is due to disturbance of the balance between the collection of water from the casing soil and the substratum, transport of nutrients and growth of the fruiting body weight (number and mass of cells and cell membranes). Transpiration may be too fast or too slow.

  • Too rapid evaporation makes the fruiting bodies lightweight, flat (Fig. 1 and 2), with the husk, prematurely stretched membrane and is often accompanied by shafts that are cracked inside. The result is a loss of weight of fruiting bodies, and thus the yield. Fruiting body with a diameter of about 4 cm (fig. 3 and 4) having the same volume can vary the weight from 40 to 25 g. Assuming a standard of 35 g, this means a large drop in yield, up to 25% with the same amount and the same size of fruiting bodies collected. This decline intensified since mid-flush collection. The appearance of light fruiting bodies, without changing of their shape does not necessarily mean that every time the reason for this is excessive evaporation. This may also be a result of water deficit in the substratum. This also happens when using dry substratum produced during the high summer temperatures. Then the watering will result in a return to the standard weight.
    Loss of water is easy to tell by observing the volume of fruiting bodies in a standard box of 2.5 kg. It can be filled in the middle (heavy fruiting bodies) in the first days of harvest of the first flush, and in following days full when fruiting bodies are lightweight and despite of this fact they have the same weight. Weight of fruiting bodies should be monitored regularly during harvest.
  • Too slow evaporation is causing greasy stains on the fruiting bodies, their growth is slow, skin is pink and yellow and there are dark rings in the stalks from which it is easy to squeeze out the water.

The current evaporation control system is based on measuring the relative humidity but it is imprecise; always indirect. The assumption that the relative humidity reflects the evaporation of water from the surface of the skin (transpiration) does not work in practice. The amount of water that can be introduced into the air, is determined by water deficit. It is not identical with the evaporation of water from the skin surface of the mushrooms. Therefore, a proposal to introduce the term „transpiration” in relation to release of water vapor by mushroom is made as opposed to evaporation of water in the casing soil or floor covering. From the standpoint of cultivation transpiration is essential.

Factors that determine the course of transpiration, are as follows.

  • The deficit of water in the air in the cultivation hall. It is described also as the relative humidity or water content in the air and read from the Mollier chart. The higher it is, the greater the evaporation is.
  • The air temperature. With the increase in air temperature transpiration increases.
  • The movement of air. Transpiration increases with increasing air speed over the fruiting bodies.
  • Atmospheric air pressure. The higher it is, the smaller the evaporation.
  • The amount of fruiting bodies and growth rate of their weight on the shelf; skin surface of all fruiting bodies. The higher it is, the higher the amount of water evaporated. Traditionally, it is advisable to increase or decrease the air changes depending on the number of fruiting bodies on the shelf.
  • The temperature of the substratum. As the temperature is increasing and the difference between the temperature of the air and the substratum is greater, the evaporation of water is greater. Differentiation of activity of substratum during the cultivation in Poland is very significant. This translates into the rate of evaporation of water from the fruiting bodies and the casing soil and the rate of growth of fruiting bodies. The current system does not include this parameter.

The problem complicate even more when we change several parameters at the same time.

Figure 1. Fruiting bodies growing at an excessive transpiration
Figure 1. Fruiting bodies growing at an excessive transpiration
Figure 2. Fruiting bodies growing with proper transpiration
Figure 2. Fruiting bodies growing with proper transpiration

 

Figure 3. Fruiting bodies before harvest
Figure 3. Fruiting bodies before harvest
Figure 4. On the scale
Figure 4. On the scale

The process of control is based on:

  • maintaining the water content at a certain level (usually it is 12 g, and the range varies from 10 to 14 g),
  • maintaining a constant air movement on such a minimum level at which the air conditioner is running smoothly and there is a movement over all the shelves,
  • air temperature changes during yielding period, mainly being increased to maintain the desired water content in the air (range from 17.5 to 21°C),
  • maintaining the desired relative humidity of the air that is based on the Mollier chart for the particular water content in the air,
  • changes of concentration of carbon dioxide (from 2000 to 7000 ppm) during yielding in order to maintain the required level of water content in the air while minimizing its movement,
  • maintaining the lowest possible air humidification in the tunnel, using watering devices installed under shelves or along the side walls.
  • maintaining percolation of water from the substratum to the casing soil.

Although control of these parameters does not always allow to achieve the desired effect in the behavior of fruiting bodies. This is due to the fact that the amount of evaporation (transpiration) is assessed indirectly.

The current control system of growth of mushrooms is based on the principles of evaporation of water, in our case with the wick of a dry-bulb thermometer. Hence the search for methods to assess the actual evaporation. One such way is to use evaporometer. For this purpose, an attempt was made using 50 g mechanical postal scale (Fig. 5 and 6). This allows to capture the moment when evaporation is blocked, as indicated by no loss of water weight, or the point where evaporation is too fast. The amount of water evaporated will depend not only on the chosen parameter values, but also on the surface of the pan filled with water.

We are currently working on determining the correct size of evaporation, watching both its size and behavior of the pins and fruiting bodies. In addition, observations are used of pace of drying floors and weight loss of fruiting bodies and appearance of the husk. Currently, it is assumed that evaporation should equal 1g over 12 hours from an area of ​​200 cm2. This issue will be returning in the future. The tests used Piches evaporometer.

The location of measurement of the parameters of the air in the cultivation hall is of significance too. At low air movements the difference in the reading of wet and dry thermometers traditionally placed in the hall and  measurement of the same parameters two centimeters above the fruiting bodies, pins or spawn reaches 20°C,  depending of the increased air movement. This means that a significant difference in measuring relative humidity.

The domination of pins. The aim is to obtain the desired density and number of generations of pins in each successive flush. The principle is that all buds are formed during shock and released in each successive flush. They are differentiated, meaning creation of generations, in accordance with the principle of diversified growth of younger and older pins and of stronger and weaker. In other words, they are differentiated by their so-called periodic arrest and release. In the first flush to adjust the density and the amount of generations initially by a shock, and after the formation of a pins differentiating microclimate conditions inhibiting the growth of weaker and smaller pins, keeping the growth of the oldest and largest (Fig. 7). In this article I’m not interested with the issue of controlling the shock, since the outcome is more dependent on experience of the person handling the shock than the process of nutrition. What facilitates replication of its course is the use feeding supplements into the casing soil. In the transitions between the flushes the process of releasing pins is also depends on other factors, of which the most important are listed below.

  • Harvest. Only conducting a selective harvesting and preventing the closure of shelf space by fruiting bodies allows for a gradual release of pins from the middle of the flush practically without interruption or with only a one-day break between harvesting of another one. Closing the shelf will reduce and delay the next flush of the fruiting bodies even up to three days, and significantly reduce the harvest period, notably during the second flush.
  • Microclimate conditions. Raising the temperature in the air and the substratum; renewal of this activity causes the released pins to
Figure 5. Post scale as evaporometer
Figure 5. Post scale as evaporometer
Figure 6. Writing down the changes of water loss
Figure 6. Writing down the changes of water loss

grow simultaneously. After completing a flush it is unadvised to change the microclimate parameters to ensure constant evaporation of water from the surface of the casing soil and its transpiration of pins, supported by a large periodic variation in carbon dioxide from 2000, up to as much as 10,000 ppm, limiting and accelerating air movement.

  • Watering. Direct watering after harvest causes the simultaneous release of the pins. Therefore, it is advisable to make one dose of water when pins are varied, for example one or two days after the completion of harvest.
  • Salinity of the casing soil. At high content it permanently reduces bonding in each flush. But this kind of salinity of casing soil is not found in Poland. It has to be induced artificially and is used primarily in the cultivation of portobello mushrooms.

It is important in the process of mushrooms nutrition to maintain a constant gas exchange between the substratum, the casing soil and the air in the cultivation hall and maintenance of percolation of water from the substrate to the casing soil. Constant evaporation of water from the casing soil significantly stabilizes the microclimate in the cultivation hall.

Knowledge of the process of nutrition and controlling it is the foundation of effective course of growth and developing one’s own technology.

Figure 7. Improper transition between the first and second flush
Figure 7. Improper transition between the first and second flush

07.2014 Green molds and mushroom feeding

Green molds are the most important pathogens infesting substrate in the mushroom production. Their presence and the development of their colonies still present the potential cause of the most serious losses. I have been interested in this problem since early 2000. In Poland, the highest losses resulting from green molds infections occurred in the years 2002 – 2009. In 2009, I published the book “Green molds in mushroom production” (PWRiL) regarding this topic.

Presently, two genera of fungi, which are considered the green molds, are described as the main causes of losses in mushroom production. The highest losses result from infections by the genus Trichoderma, particularly by Trichoderma aggressivum. The recent data indicate potential serious threats from other pathogen Penicillium hermansii (smoky mold) Hermans C., Houbraken J., Smokey Mould: the smoke screen lifts, Mushroom Business, 061 November 2013. Both these species (strains) share one feature i.e. they are considered the aggressive mushroom pathogens.

How can one characterize a current concept of losses caused by the green molds that develop in the compost and infect mushrooms?

This theory assumes the existence of a correlation between the presence of spores of pathogens such as Trichoderma aggressivum and other species of Trichoderma spp. with competitive behavior and the smoky mold (Penicillium hermansii) in the compost, and also the development of their colonies as the result of infections with spores or mycelium, and destabilizing the selectivity of compost. This hypothesis can also be illustrated in other words i.e. colony size might be larger if more spores of pathogens survive during the compost production process and the compost is less selective. The losses resulting from the primary infection are the most severe particularly if colony development occurs in the tunnel. Whereas the secondary infections that happen between the completion of compost phase II production and at spawning until applying casing cause much less losses. It means the early and severe infections while the compost is less selective results in higher losses.

Despite numerous scientific studies there are no satisfactory results that would help solve the problem regarding how to protect the compost against infections of mentioned above pathogens. This situation becomes more difficult as a current problem of losses caused by Trichoderma aggressivum disappears in itself and the smoky mold does not indicate an increasing threat. There is no information regarding new green mold infections. Personally I have seen the infection with smoky mold several times over 20 years of my consulting practice. For instance, in the past the smoky mold infections were observed occasionally and did not cause significant losses. They are not perceived in many countries with the mushroom production. Regarding this situation one can ask the question if this problem solved itself and forever? Will we experience new infections in the coming years? If the infections do occur, how do we prevent the losses? So far there is no satisfactory answer.

Preparations of the concept regarding development of mushroom production technology as controlled feeding and its implementation requires additional review of this issue. Solving the problem of yield losses caused by the green molds considers two potential possible approaches.

  1. The first approach would exclude using compost in the mushroom production that would eliminate primary infections. Instead of the compost it is recommended to apply a substrate within control of its microbiological environment; lack of primary infections and protection against secondary infections by the simultaneous introduction of mycelium and casing application.
  2. The second approach considers changes in a feeding process that would protect the mushrooms against secondary infections and minor primary infections. In this case the compost plays the secondary role in a mushroom feeding. Properly composed feeders create conditions for full control of microbial composition of compost during its recolonization after their addition into a substrate phase III. The mycelium will become so strong that it will not allow pathogens to develop and compete for nutrients. The nutrient competition and pathogen presence are a main cause of losses in mushroom production. This means necessity to provide a surplus of mushroom mycelium during the recolonization process and during feeding after the casing application that a minor primary infection will not occur, and in consequences secondary will not take place either at a stage of placing on the shelves. This is a significant advantage regarding dominance over nutrients and competitors that might be present in the compost. This proceeding should be efficient enough. This approach is based on two assumptions that are accepted as legitimate. Although the genus Trichoderma and Penicillium are the competing species and more opportunistic towards food source that the mushroom, they show different food preferences. They utilize protein better than the mushroom, suggesting that there should be lower protein content in mushroom feeding. The second approach assumes that these species are not aggressive and they become destructive only in certain environmental conditions, and this aggressiveness is transmitted into another environment via vegetative way. Aggressive behavior occurrence among competing species has already been reported and it is not very rare phenomenon. The question is what causes this aggressive behavior. The following factors might be the deciding elements: colony size of pathogen, disruption in compost selectivity and process of compost colonization by mycelium. What is the reason that aggressive species and aggressive behavior have been discussed? It results from the fact that I have never observed secondary infections with Trichoderma aggressivum in places that had prior infections. It confirms that secondary infections do not occur in production facilities with high hygiene procedures that include steaming after compost production and also in facilities with very low hygiene without steaming measures. These observations refer to hundreds of reported cases. In contrast the losses caused by dry bubble disease (or brown spot) show a clear correlation between hygiene practice and the level of colony development of this pathogen. Performed observations indicate that a diet based on high polysaccharidecontent results in very rigorous expansion of fungous in the compost and that inhibits Trichoderma and Penicillium infections that might take place during the placing of substrate phase III on shelves.

I am interested in both solutions.

However, the pathogens might colonize the supplements and cause significant losses in production if these supplements based of vegetable origin, such as ground corn, are improperly prepared and stored.

A separate aspect is a potential mushroom strain that would be resistant to the green mold present in the compost. In my opinion, it is difficult to count on such a solution mainly due to the difficulties of identification of genes that should be modified to obtain such a resistance. Besides, finding these genes is one problem and another one is an implementation of genetically modified mushrooms into production and acceptance among producers. Presently the resistance can only be achieved in the genetic modified material and that also requires funds and executor. The current lack of real threat to mushroom production yield makes this issue of little interest among mushroomproducers.

06.2014 Water in compost and feeding

Water availability in compost should go through a review due to the implementation and development of the controlled mushroom feeding concept. The amount of available water must be significantly higher than in mushroom production that provides yields in range of 30-32 kg/m2 in three flushes.

All things considered, an important factor for good production appears to be water availability in compost that is reffered to as active water or built into compost water. Currently the active water plays a significant role primarily in the compost production phase. Stored water; built into compost water source is not sufficient to achieve high yields of very high quality mushrooms. Water shortage increases when thermal effect occurs in the compost. High temperature and necessity of intense cooling decrease the amount of water availability during the feeding process.

Compost moisture content during its production phase III cannot be increased above 67-69% due to the risk of incorrect course of production process. Water excess, particularly not built into compost during phase I causes disturbances in a balance of oxygen and proper course of the phase called hot composting. It can result in developing anaerobic environment. In turn in the wet compost phase II it is difficult to control a required compost structure during stage of overgrowth in tunnels or yielding spaces such as shelves, boxes, blocks. The compost with long period of cultivation creates the most difficulties. This favors the process of rotting.

High yields require absolutely much higher amounts of water availability for mycelium rather than currently used after placing a casing layer. This can be achieved in a correctly prepared compost, particularly if straw is loose and pliable with good structure and without the presence of competing and pathogenic organisms. These high water amounts are used in feeder enzymatic degradation and transferred into mycelium from substrate. The transfer of water into mycelium protects compost from rotting and overheating. Water shortage causes dryness of the compost.

The time period during which water is added is relatively short, less than 3 days after the recolonization and achieved compost temperature min 23oC with a trend of increase. The process of adding water should be performed after blocking air availability; placing casing. Water dosage should be determined in relation to the expected yield based on the rule 2 l/m2 and introduced feeder dosage. Presently, feeder dosage has been established for processed corn grain. The schedule of adding water must be established individually for each compost. It needs to include both its quality and quantity, and dosage and type of feeder. One can not forget that the added feeder absorbs water equivalent to its wage.

Lack of a balanced feeder dosage associated with deficiency of water availability will negatively affect the mushroom production. It will result in yield decrease and worsen its quality more than without a feeder.

All tests and cultivation are carried out on a substrate made of straw and chicken manure without horse manure.

05.2014 Condition of mushrooms after an application of a maize meal as a supplement.

During the first phase of the introduced changes that were examined at the Chelkowski Farm, the supplements based on soybean meal used in the past were substituted with soybean meal prepared according to the developed own recipe. The new product was applied at the same rate i.e. 1.5% mass of substrate phase III, the same amount as others available supplements. The completed observations were implemented in further tests, which goal was at increase in yield in three flushes up to 40 kg/m2.

The most important findings are as follow:

  1. Quality improvement of primordia in the first and third flush. It was then when a concept of well-being (fruit bodies welfare) was developed. The obtained yields varied from 32 to 35 kg/m2 despite variable cultivation conditions and both quality and quantity of purchased substrate and casing layer. The yields at this level were achieved when provided substrate and casing layer were a very good quality. The level of production in a range of 25-27 kg/m2 that was observed on other mushroom farms who used the products from the same supplier was not considered as a reduced yield.
  2. Mycelium regenerated faster and the mycelium turned white sooner.
  3. Temperature increase in the substrate after an application of a casing layer was easy to control. If local overheating took place, the inner part of the substrate did not decay and there were no signs of green mold growth, which were observed when the supplements containing soybean meal were used. Overheated substrate was dry and loose. The mushroom kept producing primordia although the substrate surface has been collapsing in the following weeks. Red pepper mites did not show up.
  4. Periodically, shock could be initiated 5-6 after an application of casing layer.
  5. The substrate producer provided a compost of phase II colonized with two strains of fungi that resulted in better results. Over pinning was easily avoided and the improved quality of fruiting bodies of the more demanding strain, that was related closer to the strain from a group of U-1 was observed.
  6. Occasionally water shortage in the substrate was noticed, particularly when the substrate characterized low moisture and too hard straw, which was caused by poor removal of a wax layer and it resulted in blocking water access.
  7. Waving eelworms were found on the surface if either incorrect granulation of meal was applied or improperly mixed, and when large quantities on meal occurred between the casing layer and the substrate.

The positive results obtained from the implementation of the controlled mushroom feeding with an application of a feeder allowed gradual increase in its dose and extension of cultivation period up to four flush.