March 23 2017
In this first part we will talk about nitrogen, most important mineral element for the vine’s growth.
The vine needs 20 to 80 kilos per hectare per year to grow, build up its protein, chlorophyll, phytohormones and nucleic acids constitution.
It is thus vital for winemakers to spread their compost before the roots’ absorption period. They undergo two of these periods: 15 to 20 days before the onset of ripening, and ten days before harvest. Nitrogen must be available during flowering, but is actually used during the onset of ripening.
When the compost is spread, nitrogen will exist in organic form, as humus. Transformation from organic nitrogen to a form which the roots would be able to assimilate (Ammonium No3- et Nitrates NH4+) happens through ammonifying and nitrating bacteria. This phenomenon called mineralization needs high enough temperature (ideally 37° Celsius), a good air flow, and a pH between 7 and 8.5.