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

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

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

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.

4. 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?

2. 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;

3. 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).

4. 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