Cultivation medium presenting water availability comparable to that of a peat

Abstract

The present invention provides a cultivation medium characterized in that it is made by defibration of a bark-based composition comprising at least 70% by volume of bark, said cultivation medium having water availability that is greater than or equal to 250 mL/L.

1 . A cultivation medium comprising a defibrated bark-based composition comprising at least 70% by volume of bark, said cultivation medium having water availability that is greater than or equal to 250 mL/L. 
     
     
         2 . A cultivation medium according to  claim 1 , wherein the bark-based composition comprises at least 80% by volume of bark. 
     
     
         3 . A cultivation medium according to  claim 1 , wherein the remaining volume of the bark-based composition is wood. 
     
     
         4 . A cultivation medium according to  claim 1 , wherein the bark is the outer bark from woody plants. 
     
     
         5 . A cultivation medium according to  claim 1 , wherein the bark-based composition comprises 100% by volume of bark, and comprises:
 a fine fraction, corresponding to particles smaller than 100 μm, that is less than 10%;   a medium fraction, corresponding to particles lying in the range 100 μm to 1000 μm, that is greater than 50%; and   a coarse fraction, corresponding to particles lying in the range 1000 μm to 10,000 μm, that is less than 40%.   
     
     
         6 . A cultivation medium according to  claim 5 , wherein:
 the fine fraction is less than 5%;   the medium fraction is greater than 60%; and   the coarse fraction is less than 30%.   
     
     
         7 . A method of treating a bark-based composition, wherein the bark-based composition is defibrated, said bark-based composition comprising at least 70% by volume of bark, in order to make cultivation media having water availability that is greater than or equal to 250 mL/L. 
     
     
         8 . A method according to  claim 7 , wherein the bark-based composition comprises at least 80% by volume of bark. 
     
     
         9 . A method according to  claim 7 , wherein the remaining volume of the bark-based composition is wood. 
     
     
         10 . A method according to  claim 7 , wherein the bark is the outer bark from woody plants. 
     
     
         11 . A method according to  claim 7 , wherein the bark-based composition is defibrated by raising temperature and compression. 
     
     
         12 . A method according to  claim 10 , wherein the temperature and compression are increased by means of an auger machine. 
     
     
         13 . A method according to  claim 11 , comprising a step of grinding and screening bark, in such a manner that the extruded bark-based composition has a particle size of 25 mm to 40 mm. 
     
     
         14 . A method according to  claim 13 , wherein the extruded composition has a particle size of 10 mm to 25 mm. 
     
     
         15 . A cultivation medium according to  claim 2 , wherein the remaining volume of the bark-based composition is wood. 
     
     
         16 . A cultivation medium according to  claim 2 , wherein the bark is the outer bark from woody plants. 
     
     
         17 . A cultivation medium according to  claim 3 , wherein the bark-based composition comprises 100% by volume of bark, and comprises:
 a fine fraction, corresponding to particles smaller than 100 μm, that is less than 10%;   a medium fraction, corresponding to particles lying in the range 100 μm to 1000 μm, that is greater than 50%; and   a coarse fraction, corresponding to particles lying in the range 1000 μm to 10,000 μm, that is less than 40%.   
     
     
         18 . A method according to  claim 8 , wherein the remaining volume of the bark-based composition is wood. 
     
     
         19 . A method according to  claim 9 , wherein the bark is the outer bark from woody plants. 
     
     
         20 . A method according to  claim 10 , wherein the bark-based composition is defibrated by raising temperature and compression. 
     
     
         21 . A method according to  claim 12 , comprising a step of grinding and screening bark in such a manner that the extruded bark-based composition has a particle size of 25 mm to 40 mm.