Green Manure: Nourishing the Soil, Protecting the Future
What is Green Manure?
Green manure is an ancient and valuable agricultural practice that involves sowing a mix of different plant species chosen for their ability to produce a significant amount of biomass.
During the winter, this cover crop helps protect the soil by limiting erosion caused by bad weather. In spring, it is then incorporated into the soil between vineyard rows.
We use a specific seed mix made up of:
- Legumes such as fava beans or clover, appreciated for their ability to fix atmospheric nitrogen into the soil;
- Cruciferous plants like mustard, which help to aerate the soil thanks to their root systems;
- Grasses such as barley or oats, which improve soil structure.
Sowing takes place in autumn, right after the grape harvest, to take advantage of favorable weather conditions that support seed germination and early plant development. Ideally, we sow just before a rain, to ensure quick and even germination.
During the winter months, growth slows down, but the vegetative cover remains essential for protecting the soil.
When and How to Incorporate Green Manure
To achieve the maximum fertilizing effect, green manure should be incorporated before the plants begin to flower.
During flowering, plants start consuming the nitrogen previously accumulated, reducing the amount that returns to the soil.
In recent years, however, due to increasingly mild winters, flowering often occurs earlier than expected. To avoid having to cut down the cover crop too soon—thus exposing the soil to late winter and early spring rains—we’ve adopted a natural solution: we let our sheep graze on the green manure.
This approach allows us to:
- Slow down the natural flowering of the plants;
- Keep the soil covered for longer;
- Provide fresh forage for the sheep even during winter;
- Benefit from natural and direct fertilization.
After grazing, we allow the plants to regrow and accumulate new biomass, which is then incorporated into the soil in April.
Final Steps: From Green Matter to Living Soil
At the right time, we proceed with mowing or shredding the green manure. If needed, and if weather permits, we allow the material to dry for a day or two. This step helps reduce the moisture content of the biomass, making decomposition easier once it’s incorporated into the soil.
The biomass is then turned into the upper layers of the soil, where it begins to decompose and mineralize thanks to the activity of soil microorganisms.
The benefits are numerous:
- Increased biological activity in the soil;
- More organic matter available to the vines;
- Improved soil structure, promoting better water retention and penetration;
- Reduced nutrient loss and erosion.
Ultimately, green manure represents a true form of natural fertilization that enriches and protects the soil—creating the ideal conditions for healthy, sustainable viticulture.
