Insight into the Truffle Farming

Although some regions are moving, either independently or with the aid of truffle growers associations at the forefront of the defense and improvement of truffle host-plant ecosystems, we are witnessing a progressive and inexorable depletion of natural truffle grounds.
There are many factors that have favored and still favor this decline.
The phenomenon began in the 1960s-1970s with the rural population’s mass exodus that resulted in the abandonment of the so-called marginal lands located mostly in the hills and low mountains where truffles find their widest possible distribution. In parallel, industrialized agriculture, supported by ever greater and more powerful mechanization, has helped to upset the rural environment, particularly with the systematic elimination of truffle-hosting trees, either singly or in rows, which were important and characteristic natural breeding grounds for truffles. In addition to this, such other undertakings as land reclamation, water regulation, dam construction, and so forth produced similar results.
For these reasons, small plots of land were abandoned and then withdrawn from farming because they were either no longer suitable or, in some cases, almost entirely unsuitable for any kind of mechanized cultivation. The result was that, within 10-15 years, there was a natural recolonization by trees and shrubs or, in any case, a thickening of these areas. The first to appear were shrub species like bramble, greybeard, blackthorn, broom, etc., followed by tree species like oaks, hornbeams, hazels, pines, etc., creating excellent natural shelter for animal species like wild boar, deer, and others.
Since the 1990s, the lands set aside for wildlife protection, national and regional parks as well as nature reserves and havens have also increased considerably. This has led to a disproportionate increase in such truffle-loving animals as porcupines, badgers, and especially wild boars. The latter not only deprives the truffle hunter of the product and consequently also the market but, as it looks for truffles, always damages the truffle ground, often destroying it beyond repair.
If that were not enough, another equally worrying phenomenon in recent years has been climate change, with a clear increase in average temperatures accompanied by severe periods of drought that have resulted in significant product loss.
Finally, there has also been a steep increase in truffle hunters with increasingly select and thus more talented dogs, resulting in the complete removal of the product, and seriously endangering the survival of natural truffle beds.
This situation can only be remedied via truffle farming.
Despite being the biggest producer of truffles in the world, and almost the only producer of white truffles, Italy is bringing up the rear in this field with countries like France and Spain – whose truffle growing traditions are much more recent – being ahead of us. In France, it is estimated that 90-95% of the product placed on the market comes from cultivation. Spain has thousands of hectares of cultivated truffles, especially black truffles (Tuber melanosporum Vitt.) owing to a systematic and unique governmental plan, thanks to which its production is already greater than Italy’s. Other European countries (e.g., Hungary and nearby Switzerland) have been taking serious steps in this direction.
Around the world then, some countries, mainly New Zealand and California, have been so successfully developing truffle cultivation for about twenty years that now even prized black truffles are sold in Europe during the months of July and August. This is because we are talking about states with climatically opposite seasons.
This matter, however, is not new but should be taken very seriously because we believe it would be of great help in assuring an adequate supply of the product in the future. As symbiont hypogean fungi, truffles need a partner (almost always a host plant) in order to grow; a previously mycorrhized tree is necessary to cultivate this plant. Because our country’s legislature has not provided clear regulations, this type of cultivation has been harmed by the unscrupulous seedling-producer farms that have taken advantage of the good faith and even the ignorance of some people by offering plant materials that have been poorly and badly mycorrhized in unsuitable soils and often at exorbitant costs. As a result, there have been some failures, yet there have also been many successes, some of which are truly striking. We are talking mainly of the cultivation of black truffles: T. melanosporum Vitt., T. aestivum Vitt., T. unicinatum Chatin, T. albidum Pico.
Carpophore production, referring to the arable hectare per main species of truffle, is highly variable and difficult to quantify. In general, there is no reliably certain and especially confirmable data since each environment is always different from the others, the weather is different each year, and each producer uses his own particular technique. Of course, if water and a fixed irrigation system are available, the chances of success are higher and production is clearly doubled or tripled in comparison to a dry crop. However, even with an irrigation system, there are currently no quantitative standards. If a soil is particularly skeletal and shallow, therefore draining, sprinkler irrigation of about 20 mm distributed over a 4-6 hour period without natural rainfall, must be repeated in the hottest months (July-August) every 7-8 days. On the other hand, if the soil is a deep, sandy loam with the presence of organic matter, the irrigation can be repeated every 12-15 days using the same amount of water.
Above all, experience and personal knowledge leads us to state that the Tuber melanosporum has achieved the highest production levels, with about 150kg per hectare, followed by the Tuber aestivum with 120-140/ha and the Tuber albidum with 40-50/ha, always with an irrigation system in place. These are some examples of rational truffle cultivation certainly carried out in suitable soil, with the possibility of irrigation, using appropriate truffle species, with very well-mycorrhized seedlings free of antagonistic pollutant fungi.
In the last two harvest seasons, 2011-2013 – perhaps the worst of the last 60 years – we found that all the prized black truffles placed on the market were cultivated using irrigation systems. Apart from sporadic cases, it is important here to keep in mind how irrigation use in natural truffle-grounds has proven difficult. The use of irrigation is indeed sine qua non for cultivated truffles.
Let us stress that the above is difficult to apply to white truffles as they have very specific ecological requirements that are difficult to reproduce artificially; their spores also have difficulty germinating; and a DNA analysis of the mycorrhizae produced are often inexplicably linked to T. albidum forms. All these factors currently make its cultivation inconvenient and risky. The reported successes are few, and they are perhaps related more to chance than to a true cultivation system that may be implemented on a large-scale.

Here follow some practical suggestions for the development of new facilities in order to achieve greater success:

• Make sure that the selected area is well-suited for truffle cultivation.
• Physicochemical analysis of the soil.
  In general, all truffles favor distinctly calcareous soils, with a pH generally between 7 and 8 and a good amount of CaCO₃ (limestone). The black truffle turns out to be absolutely the most demanding as regards these parameters, while the whitish or marzuolo truffle is the most tolerant. In the specific analysis we will look naturally for the pH, overall CaCO₃ but especially the active one, the exchange capacity as well as the texture and grain size.
• Eco-climatic and vegetational analyses.
• Check the climate, exposure, slope, altitude.
• Check water supply for possible irrigation (pond, well, stream).
• Choice of truffle species of symbiotic plants and nursery supplier.
  In particular, as regards the purchase of mycorrhized plants, along with the soil’s physicochemical characteristics, an extremely important factor is the right choice of nursery supplier.
  Among the many suppliers, we are able to give advice on and recommend the best in this field. In order to avoid the risk of encountering companies lacking credibility and hence of not achieving the desired results even after many years, we strongly recommend that you contact us for our opinion.
  From our personal experience we can say that the systems made with well-mycorrhized plants have given impressive results so far, with a 99% success rate of producing plants, resulting in the first harvest as early as the third year after planting.
  Please note, however, that full production arrives no sooner than the sixth or seventh year, considering the many variables that come into play (climate, altitude, soil, irrigation, plant care, etc.).
• Planting layout, planning of the possible irrigation system and enclosure if necessary.
• Crop management plan.