Ten years soil diagnosis in vineyards, with particularly analysis of organic and microbial mass and measuring their evolution

Since 1996, we study the soil in viticulture, specially in the South of France. In the field, we delimit soil units and observe soil profiles and take samples to analyse its physical, mineral, organic and microbial mass composition. We also analyse the rate of roots mycorhization. 
For few years we used both Y. HERODY (BRDA) analysis and Xavier SALDUCCI (CELESTA) ones. Since 2004 we have adopted only Xavier SALDUCCI analysis menu : two compartments of organic matters, microbial mass and mineralization activities of carbon and nitrogen. 
Here are shown the results of 100 organic and biological analysis: 
– Carbon level is low to very low (less than 10 g /kg ) : 56% of the plots. 
– Nitrogen level is low to very low (less than 1 g/kg) : 64% of the plots. 
– Microbial mass is low in 71% of the plots (less than 200 mg of microbial C /kg). No plot has a level higher than 400mg of microbial C /kg. 
– Carbon Mineralization Activity is high to very high, more than 400mg mg C-CO₂ /kg/28 days, in 49% of the plots 
– Nitrogen Mineralization Activity is low to very low (less than 1 mg de N-NO₃^– N-NH₄⁺ /kg/28 days) : 53% of the plots. 
Since 2006, we control organic and biological evolution specially in plots where green manures and composted organic matters have been used. In 4 plots where the analysis showed (in 2001) a very high lake of organic matter and microbial mass, we not that : 
– The organic matter level has been partially improved . Bt the rate is still low in two parcels. 
– The microbial mass has been improved even it is still low in two parcels. 
Even, if the levels are still low, the vine is more healthy : no more nutrients deficiency symptom, the vine growth is more homogenous, the yield and the crop quality have increased, with a real expression of the “Terroir”. 

Author:  Karim RIMAN 

Consultant en agriculture écologique 
Mas de La Cigalière – RN 100 – 84250 Le Thor – France 

Email:  karim.riman@consultant-agriculture-ecologique.fr 

Keywords:  diagnostic du sol viticole, matière organique, biomasse microbienne, minéralisations du carbone et de l’azote