Production of Compost, Personal opinion (part 3)

Principles of raw materials selection

Tsarev Alexander

When we decide about the technology for the first phase of composting, it is time to think about the raw material for composting. In the available literature on this subject was written quite a lot, but usually it all comes down to the fact that horse manure is ideal and necessary component, and straw have to be a new crop, yellow color and not too short.

It is reason, why it comes, when they try to find answer, about bad compost quality, that they give answer it is because of "not so" good and proper straw quality. As a source of nitrogen, mineral source of nitrogen is, considered same to the organic nitrogen source, although their roles for composting processes are not equally. In this kind of formulation, the compost contains so many components that when you read the last, you already forget what the first on compost formula list was. With fever components in the formula of compost, seems it will be easier to calculate the formula, and more real to predict the interaction of these components with each other, their behavior in the process of composting. In addition, we have to mention the economical point of providing all these multiple ingredients.

Further (even I am again afraid of the wrath of fans of clear recommendations),
I will try to articulate my vision of the principle of selection of raw materials for composting. Moreover, of course, this is my purely personal view, which is not in any way claim to be ultimate truth.

Start thinking about it is best from the end of process, from the goal what we have to achieve, when we prepare compost.

This goal is quite straightforward, and consists of two main points.

The first point: provide food, for mycelium’s growth in the compost to produce vegetative mass of mycelium. This is in order to provide sufficient food and water supplies, to be able to produce a full crop of mushrooms in due process terms. To create such an ideal "mechanism" of fruiting is possible only by summation two types of mycelial growth in the compost – a “surface” and "bulk".

Term "superficial” growth of the mycelium is undertaken as quickly mycelial overgrow of the surface of particles of straw, without filling its volume. However, at the same time, without the development of the total straw weight "superficial growth " of mycelium in the compost unit is far from total possible.
As a result, of this “superficial growth”, the mushroom first flush will be weak, and further fructifications will be very slowly, and long time, even if there is enough food for mushrooms development. In this case, compost became "old" much earlier; even before the total, potentially harvest would be finished. By the way, compost overgrown only "superficially" is completely unsuitable to make from it, IC (incubated compost) as “Cacing” to casing material.

When cover "bulk" of the straw in compost, mycelium overgrowing internal volume of straw. On this way, it gives much greater mass of mycelium in comparison with the "superficial" overgrowing. Accumulated food in the mycelium, guarantees at least a good first mushroom flush from this compost. In practice, it is up to 25% by weight of compost. Harvest the second and third flush will depend on the availability of sufficient food to form mushrooms “fruitbodies” in further flushes.

In the case of the presence in the compost only "bulk” of overgrowth, (which is rare) - mycelium grows rather slowly, and the third mushroom flush could be increasing significantly, leading to the failure of technological work schedule.

Nutrition material needed to feed mycelium for completely “bulk" overgrowing compost is well known, because it is cited in almost every literary source. This is humus lignin complex with N incorporated.

What is regarding food for myceliar "surface" overgrowing straw in the compost, about it is writhed much less frequently. Nevertheless, for this, it is not diminishing value of this food. This is protein mass of dead microorganisms involved in the formation of lignin-humus complex with N incorporated.

The second point of the composting – it means to provide food, for “fructification”, growth mushroom “fruit bodies” of good quality and in sufficient quantities and for at least three flushes of mushroom picking. It is a complex Carbohydrate. Usually, dealing with other cultivators, we call these simple carbohydrates are organic mater. Not important what we call it, since the essence of the names stay same. For example, good myceliar overgrowing of compost, and good yield in first flush of mushroom, does not always guarantee a high overall yield on this compost. Only if there is enough organic matter in this compost, what are necessary for the formation and growth of fruit bodies in later waves.

Based on the foregoing we can conclude that in the finished compost we are interested in three main substances:

• Lignin - humus complex with N incorporated;
• Organic matter is essential for the formation and growth of fruiting bodies;
• Rest of microorganisms involved in the composting process and the formation of the first two positions.

In this case, it seems that for the "complete happiness" of mushrooms probably needs something more. Therefore, we emphasize that needs three basic things. For example, in the last 2 - 3 year at some mushroom farms where I work as technologist adviser, it began to developing knowledge of the fourth component of the quality of compost. However, before I have the full clarity, about it, to talk about it is too soon.

Of course, physical and mechanical properties of the compost has very important role with this previously cited, but about them later.



Let returning to the subject of selection of raw materials.

For beginning, we need to understand what material we need, to make a lignin-humus complex with N-incorporated. The first thing that comes in mind is that we need to provide a lignin. Lignin quantity in the composting process itself is not passing to virtually any change. The only thing that happens to it is that the lignin just has adsorption of humic acids. Hence, the first requirement for raw materials - it should contain a sufficient lignin quantity.

However, to pick up materials only on base of the content of lignin, is wrong. In addition to this organic matter in the raw material must be present complex carbohydrates, necessary for the formation and growth of fruit bodies of mushrooms. Carbohydrate quantity directly has influence to the mushrooms yield. Because of it, second requirement for raw materials is- the maximum content of these carbohydrates.

The third point for raw material choosing is to obtain next condition as follows. During fermentation process, what is taking place during the preparation of compost requires certain conditions. Let us consider one of them - the temperature. All the composted mass must pass through certain stages of the temperature in a certain order and in the recommended period. To warm up this mass, it must be something to "light" and to support this "burning" for a while until it earns major "energy mechanism." This "ignition" is the simple carbohydrates, so called, readily available. Microorganisms begin their work on composting eating this food, readily available carbohydrates. Naturally when starts to produce the energy, it raises the temperature of the compost mass to the necessary technological level.

The third requirement - the raw material must contain an easily accessible organic material in an amount sufficient to begin heating fermentable mass.

Now is the time to think about where to find lignin-humus complex with N incorporated? This complex is forming from humic acid, which at high temperatures (above 75˚Celsius) combined with lignin and forms required food for mycelium, what provide food for completely overgrowing of the compost. In turn, for the formation of humic acids is necessary mostly organic Nitrogen! Organic nitrogen, or proteins, by the process of ammonification are split to their components and these components under certain conditions form the humic acid. I apologize for such a simplification of the process, but it is clear to all who explained, and as a result people are getting very good results (yields).

Therefore, the fourth parameter of raw materials –has to have sufficient organic N content. In practice, it has to be preferably not less than 3%, the maximum is not limited (perhaps only the cost and availability of such raw materials).



At the end of the list of requirements for raw materials can only add requirements such as:

• availability of physical and mechanical properties needed for the composting process (moisture content, structure);
  
• 

economic and physical accessibility;


  
• the ability to store, or the continued availability for purchase;


  
• minimizing raw material preparation before laying compost.
  

If you have patience and read carefully all of the above, we can conclude that, ultimately, in the raw material for the compost we need two basic substances. This organic matter in a variety of carbohydrates, which can be easy to understand and calculate the formula of compost called Carbon. The second material necessary for the formation of humic acids - organic nitrogen, or just Nitrogen. Given the need for a certain ratio of Carbon and Nitrogen at the beginning of composting, it will be very difficult to pick one type of raw material to the desired ratio of carbon to nitrogen. On the other hand to pick up too much different component of raw material, make up too anything good from an economic, organizational and other parties. In addition, what a more different components of raw material, that is smaller their share in total volume, the more difficult to distribute evenly these components of the total mass. Moreover, this has a direct effect on the homogeneity of the compost and on its quality. This is especially true for the various kinds of additives.

Therefore, to make compost using two basic raw materials, carbon and nitrogen and will be the best option. It can be just wheat straw and chicken manure. Why is wheat straw - because in it the optimal combination of all types of carbon in sufficient quantity. Very similar characteristic’s has rye straw. In other types of straw and mix the contents of three types of carbon (carbohydrates) is less than optimal, which affects ultimately the quality of the compost (though cannot get a record, but quite a decent crop of mushrooms).

As for the chicken manure, the main requirement for it is the maximum content of organic nitrogen, minimum 3% of dry matter. The difference between dry chicken manure, and wet chicken manure from cage, is just in the cost of transport (chicken manure from cage, is far more manure needed), conditions of storage and use of technology.

There is a very important point, which determines the value of raw materials like carbon (straw) and nitrogen (chicken manure). This is the content of the mineral balance, that is, the ash content. The fact is that mushrooms are almost no using the mineral raw materials. Therefore, as less has this ballast material, the more food is possible to produce in the compost, what is made from this material. This is the parameter, the ash content what determining does straw is fresh or not, but not the year of its production and harvesting. Straw can be quite "fresh" and after 3 - 4 years of storage.

The last thing I wanted to write in this part - it is about horse manure. A fairly large part of the mushroom growers, both beginners and has already taken place in mushroom growing, talking about horse manure as something perfect for making compost for mushrooms. It can be understand that such an attitude to this raw material is because the ratio of carbon and nitrogen in it is close to the ideal 28 - 30. It seems like here it is, raw materials, in which all matched! One parts of the mushroom growers "just swallowed bait” and the other just trusted that part. However, unfortunately, the nitrogen contained in horse manure is 70% in the form of ammonia and is easily lost by evaporation mineral, in the best case, has just the role for the primary heating composted mass. For the formation of humic acid is still required an organic nitrogen, which in horse manure virtually none. In addition, the availability of manure in large volume became rather big question, not to mention its homogeneity. By the way, all very high yields, with whom I had have encountered, had been obtained on compost without the horse manure.

Unfortunately, in this part of the case to the formula of compost did not make it, but in the fourth part will dwell on it as detailed as possible.