What is the annual loss per hectare?
The annual loss of organic matter must at the least be compensated to maintain the soil balance. Soil analysis gives an approximate value for the loss of OM by mineralisation (coefficient k2) that must be replaced. This value should be adjusted depending on whether cuttings after pruning are returned to the plot or not.
Example: on a typical plot where the cuttings are not returned to the soil, the loss is estimated at 300 kg/ha/year. Over four years, a minimum of 1.2 tons of organic matter should be added. Assuming that the chosen input contains 450 kg of organic matter per ton, it will be necessary to apply a minimum of three tons per hectare over the four years.