Truffle farming

La trufa negra de Teruel

Truffle farming in Teruel

The best black truffle in the world, the Black truffle of Teruel, is produced and harvested in the land and mountains of our province.

Our Mediterranean climate, characterized for being extreme, moderately warm and dry, with cold winters owing to the altitude, promotes the growth of suitable vegetation. Also, droughts, the precise and necessary rainfall, as well as an arid and chalky soil, added to the experience and efficient practices of our people, turn Teruel into the Spanish province with more prospects to produce high quality truffles.

Truffle farming in Teruel relies on three basic pillars: an adequate soil, an appropriately mycorrhized plant adapted to the environment and, finally, some supportive cultural labor. An expert’s advice is very important when projecting a truffle plantation.

How to choose the plot

The best plots are those with limestone soils, a pH between 7 and 8 and few fungi to compete with the truffle. Farming soils are more propitious than forest soils.

How to choose the symbiont plant

Black truffles combine with trees that live in very special soil and climate conditions, thus it is necessary to plant some species that adapt to the ecologic conditions of the place.

Truffles live necessarily in symbiosis with forest species like oaks or holm oaks, so these trees, that carry the fungi in their roots, are prepared in specialized garden centers to be put in plantations.

It is advisable to purchase certified mycorrhized plants that have spent at least one or two years in a specialized garden center.

 

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The most typical symbiont plants in Teruel are:

  • Quercus ilex or Holly Oak (Holm oak)
  • Quercus faginea or Portuguese Oak (Gall Oak)
  • Quercus coccifera L. or Kermes Oak
  • Corylus avellana or Hazelnut tree

Cultural and Forestry Actions

Besides the steps already explained, the following actions must be taken to set the truffle plantation:

1. Prepare the land
The preparation of the land will depend basically on the way we manage the soil during the first years (preproduction stage) as well as on the status of the land surface before the plantation takes place.

In general terms, it is important to do a great effort to break the possible sole of work and favor the drainage and ventilation with a mole plough and a moldboard plow. Then, the surface must be leveled and the ground flattened with harrows or cultivators. The best seasons to do this are summer and autumn months prior to the plantation; the soil must be dry and the different ground stratus should not merge.

2. The plantation

The plantation density will depend mainly on the ground fertility, which is closely linked to its depth and the organic matter and clays. Density will be lower in fertile soils.

The density also varies according to how the soil is maintained. Thus, if you are planning to work the land frequently, you should leave more room between the trees.

 

 

The plantation density ranges from 200 to 400 trees per ha. with a recommended positioning of the plants as follows: 6×6, 7×6, o 7×5.

The plantation must be done during the dormant period, in spring or autumn, to avoid intense frosts.

3. Soll management

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Land cultivation

Cultivation is done with the purpose of improving the soil structure, increasing its water retention capacity and promoting the development of the truffle fungus.

By moving the soil of the glade the rain water will soak into the ground and dampness will remain for longer. This way we optimize the tree and its root system growing process. Work on the land should always be superficial, deepening less as we move away from the glade central area, which is the trunk of the host tree, though it is most common to give it the same depth.

Irrigation
In order to ensure the good yield of the plantation it is advisable to install an irrigation system for the glades. This procedure will help you combat rain water scarcity.

Irrigation must be carried out in a careful way in order to avoid water logging.

Our recommendation is to water regularly during the first years until the root system is established. Particularly during the first year, plants should be irrigated in the event of a prolonged drought.

In the production stage, between the months of July and half August, water needs are very low but a heavy irrigation is recommended in case of prolonged drought. Nowadays it is not advisable to water using drip irrigation; use sprinkler or micro-sprinkler irrigation instead.

In case irrigation is not possible, you can try and mulch, as this is usually done to avoid water loss trough evaporation during the summer and it can help keeping ground moisture for longer. In spite of the fact that it doesn’t seem to be unfavorable for the fungi, it is advisable not to keep the mulch for an extended period. Once the land cultivation has finished, mulching can be done with crushed limestone on the wet soil. Other kind of material can also be used on the ground: slabs, almond shells…

Fertilization
After analyzing the soil, you can compensate for the lack of nutrients.

Fertilization is generally not recommended.

Fertilization should only be used when the truffle production declines.

Pruning time
The pruning is carried out with multiple purposes: to avoid the trees and their root system to grow up too vigorously, to anticipate to the thick vegetation blocking the area, to correct anomalies and to create favorable conditions for the development of truffles. By pruning you will get an appropriate lighting for the soil, as well as favor the sprout of superficial roots to the detriment of the deepest ones. Besides, pruning eases the further installation of an irrigation system and facilitates truffle harvesting.

It is advisable to prune every year during the dormancy period so that the top tree is little high, inferior to 5 m, with the shape of an inverted cone and little thick foliage. Those branches growing vertical and the lowest ones will be cut, as they shade the ground.

Prunes will be gentle; moderate cuts will be done to the intermediate branches, more emphasis will be put on the higher ones and finally, the lowest branches will be eliminated.

Land protection. Fencing
It is convenient to fence the plantation in order to protect it and the investment it entails. Fence should be 1-1.5 m tall so that animals like wild boars, uncontrolled cattle, poachers and vandals cannot enter the plantation.