Cover Crops in the Vineyard: Research and learnings

At Herència Altés, we work every day to better understand our environment and to advance practices that allow us to produce high-quality wines in a sustainable way.
One of our ongoing projects is the use of vegetative cover in our vineyards — a technique that provides clear benefits for the soil and biodiversity, though it also presents challenges in dry regions like Terra Alta.

A Journey of Research

Our relationship with cover crops is not new. Back in 2016, we began testing alternate-row cover crops (one row yes, one row no), a practice that we still maintain today whenever the weather allows.

In 2022, together with VITEC – Wine Technology Center, we launched a more detailed study to evaluate the impact of cover crops on the vineyard. Since then, we have continued monitoring and recording results to better understand their effects under dry-farming conditions.

The Trial: Cover vs. Tillage

To deepen this understanding, we established a trial with 3 rows of vines under full cover and 3 tilled rows, comparing three soil management practices:

• Traditional tillage

• Alternate-row cover crops

• Full vegetative cover

The results show that soil management significantly affects fertility, microbiology, and vine performance:

🪱 Healthier, more balanced soils
Cover crops —especially full cover— significantly increase the diversity and abundance of soil microorganisms. This improves soil structure, water retention, and nutrient availability, creating a more balanced and resilient ecosystem.

🌱 Improved vine nutrition
Vines with full cover show better nutrient absorption, particularly of nitrogen, potassium, and copper, with higher levels of organic matter and phosphorus in the soil.

💧 Greater water efficiency
Vines under full vegetative cover show better water management. They display fewer signs of water stress and keep their leaves more active, breathing and photosynthesizing more efficiently. In practical terms, this means they make better use of every drop of water, even in very dry years, and maintain a more intense green color due to higher chlorophyll content.

🍇 Impact on yield and quality
As expected in such a dry environment, grape yield decreases under full cover, while the mixed treatment (one row with cover, one without) offers a balanced outcome: intermediate yields and good grape quality, with slightly higher potential alcohol and lower acidity.

🌿 Phenology and vigor
Vines with full cover advance their phenology slightly and develop thicker shoots, whereas tilled vines tend to grow longer shoots and produce higher yields.

Conclusions

Our experience confirms that, although vegetative cover may slightly reduce yield, it brings clear benefits for soil health, biodiversity, and water-use efficiency. In a dry climate such as Terra Alta’s, the mixed management system appears to be a balanced strategy, combining sustainability with productivity.

Our Commitment

This project represents only a part of our journey toward a more respectful, landscape-driven viticulture. We know that maintaining cover crops in such a dry area as Terra Alta is not easy, but we also know that the future lies in learning to live in harmony with nature and finding balance between production and sustainability.

At Herència Altés, we will continue to share the results of this research, hoping to contribute to collective knowledge and to help build a more sustainable viticulture for future generations.