Agroforestry, a practice in favor of the environment

You have probably already heard about it, agroforestry is the association of trees and annual crops or animal breeding on the same plot. Although it is an ancestral practice, it has rather been neglected until now. However today it is more highlighted because it allows a better use of resources, greater biological diversity and increased yields thanks to the creation of a favorable microclimate.

From a societal point of view, it responds to the growing needs of consumers to have a quality product, with minimal impact on natural resources.

This method of farming, which is increasingly being used in viticulture, presents numerous benefits for economic, agronomic and environmental performance. Adapted to the vineyard, we also speak of vitiforestry which responds to the current sustainability challenges of the wine industry.

The principles

Associate the tree with viticulture

A true symbol of rurality and the landscapes of our regions, 70% of bocage hedges have disappeared from the French landscape since 1950. We can imagine that the tree is rather inconvenient for agricultural work. In the middle or at the edge of the field, it can be disruptive when maneuvering with the machines. But today farmers, and in particular wine growers, want to associate the tree with their activity, thus turning their back on monoculture. The tree is gradually reintegrated into the life of the agricultural territory.

Favor local species

Adapted to local soil and climate conditions, plants will develop optimally. Choosing local trees and shrubs therefore means avoiding the propagation of invasive species which develop due to lack of competition and their ease of adaptation. They represent a danger for the rest of the plants which have fewer resources at their disposal. By extension, animals dependent on these native plants are also impacted. Winegrowers can be helped in the choice of plants by the local plant labels which guarantee the provenance of the trees and shrubs. The right tree in the right place!

Diverse species

In agroforestry, we seek to imitate the functioning of forest ecosystems: a layering of different strata (trees, shrubs, herbaceous plants) to bring diversity and organic elements to the soil. In addition, there are soil conservation techniques: reduction or no plowing, permanent soil cover, direct sowing, etc.

Each tree species has its own characteristics (water requirement, root depth, disease resistance, etc.), each therefore reacts differently to climatic and ecological hazards (insects, diseases, storms, drought). In agroforestry, it is therefore preferable to diversify the species of trees and shrubs. In addition, wildlife prefers hedges made up of varied species offering a multitude of natural habitats. The diversification of species also makes it possible to spread out flowering and fruiting, and thus to provide food at different periods. For example: elm and cherry are early fruiting species, rosehip and holly produce berries in winter, oak fruits from September to March.

In vitiforestry, it is appropriate to select species of trees and shrubs adapted to the terroir of the vine, diversified to shelter a varied auxiliary fauna and if possible with light foliage and little competition for light.

At Château La Rose Perrière, 517 trees and shrubs, that is to say 1,300 linear meters of local, climbing, fruit and honey species, were planted in February 2022. Five lime trees, six apricot trees, eight apple trees, eight pear trees, eight peach trees, six cherry trees, eight almond trees, forty olive trees, fifty Judas trees, forty-five buckthorns, fourteen chokecherries, ninety-two dogwoods, fifty-three European spindle trees, eighty-one blackthorns, forty-three black elderberries and fifty wood privets now adorn the gardens and the surrounding area of the vineyard.

Resilient species

In a logic of sustainable development and long-lasting agroforestry, it is important to select species that will be able to cope with increasingly extreme and frequent climatic events. If certain species such as the common walnut, the field maple, the common chestnut, the holm oak or even the wild apple tree are adapted to climate change, others are on the contrary not adapted and will gradually die out: the red oak of America, the common beech, the common spruce, the aspen poplar, the Douglas fir,…

Generally speaking, bocage hedges will be functional and resilient if they are interconnected, we then speak of a bocage network, if they have sufficient thickness and if they are composed of a diversity of strata, structures (low and high hedges, alignment of trees on slopes, etc.) and ages (young, adult and aging trees).

Ecological management

In order to contribute to the maintenance of biodiversity, ecological management must be considered. Plant protection products must be limited as much as possible and in the same way, deep plowing which kills many insects and larvae living in the soil. Planting a hedgerow only makes sense if it is managed ecologically.

A plantation adapted to the needs of the farmer and pedoclimatic conditions

The composition of a bocage hedge differs depending on the needs of the farmer. To create a honey hedge, for example, the farmer will have to select species that meet the needs of pollinators: pistachio, blackthorn, dogwood, almond, fig, olive, flowering ash, Honey.

Care taken during planting

From the start in agroforestry, once the choice of species and planting density has been determined, it is important to plant them by the book. The farmer-wine grower will establish his planting plan (density, orientation, distances between rows) and must follow several rules at each stage from preparing the land to monitoring the plants. The planting period should be the subject of particular attention. It must take place in winter, outside periods of frost and strong winds. These choices also depend on the farmer's objectives, soil constraints, the production system, the size of the agricultural machines working on the crops, etc.

Finally, we must not neglect the grassy strips which will be installed before planting the trees, ideally 4m wide, and will be composed of grasses and leguminous plants. They thus contribute to slowing down runoff, stabilizing the soil and maintaining humidity.

Connection to surrounding ecosystems and landscapes

The interest of agroforestry is to extend the positive impacts beyond the farm. Hedges are real traffic routes connecting meadows, woodlands and other ecosystems. These are “ecological corridors” which have a role of refuge, reproduction and nesting site, and feeding place. By connecting ecosystems, hedgerows enable a genetic mix of species and provide easy access to a multitude of habitats.

The different types of viticultural agroforestry

In viticulture, an infinite number of agroforestry developments can be considered. The audacity, imagination and financial investment of the winegrower will be the only limits. There are several types of viticultural agroforestry, including:

• plots of vines interspersed and surrounded by a mesh of rural hedges: we speak of a bocage wine-growing system,
• rows of trees interspersed between the rows of vines,
• shrub hedge at the edge of the plot or between islands of vines,
• isolated trees planted within the row of vines, interspersed between the vines and overhanging the vine.
• isolated trees planted within the row of vines, interspersed between the vines and kept low by pruning (trognage).

At Château La Rose Perrière, the bocage wine system was adopted by the Sylvain family. Country hedges adorn the perimeter of the vineyard.

The benefits

Rethinking the establishment of trees or hedges within the vineyard does not only have landscaping benefits. Indeed, multiple benefits arise from a wine agroforestry project.

Fight against global warming and protection against climatic attacks

The benefits of agroforestry against global warming are measured on a local and global scale.

On a local scale, trees planted on agricultural land create a microclimate and help protect crops from climatic hazards (wind, extreme cold, drought) but also from natural hazards such as floods and storms. On a vineyard plot, trees and hedges provide “climate control” and reduce climatic stress by creating a barrier and windbreak effect.

Globally, there is evidence that increasing green cover helps reduce greenhouse gases through the carbon sequestration capacity of trees, reverse global warming and block sea level rise. of the sea. When correctly implemented, agroforestry also allows deep aquifers to be replenished over centuries or even millennia.

Improvement of above-ground and underground biodiversity

Biodiversity in agroforestry systems is obviously higher than in conventional agricultural systems. Each of the species added to a given wine-growing area complicates the habitat for fauna which can be accommodated in a greater variety. At Château La Rose Perrière, nearly 200 plant species have been planted to promote the development of biodiversity and our vines.

Promoting soil and plant growth

Depleted land can be protected from soil erosion by ground cover plants such as naturally growing grasses in agroforestry systems. These help stabilize the soil by increasing coverage compared to short cycle cropping systems.

Better filtration and infiltration of water into the soil is another advantage of agroforestry. Crops then benefit from cleaner water thanks to reduced nutrients and runoff.

Source : Ministère de l’Agriculture, de l’Agroalimentaire et de la forêt

Social and economic benefits

By adopting mixed farming and integrating trees, fruit trees and shrubs into the vineyard plot, the cultivable space is optimized to access a greater diversity of production, or even additional income from the production of honey, sale of fruit,…

Disadvantages and challenges

As virtuous as it is, agroforestry has some disadvantages and still face challenges and obstacles. Indeed, the advantages of adopting agroforestry practices and sustainable approaches remain unknown and still hamper its development today.

Establishing an agroforestry system can also be costly and require significant investments in equipment and qualified personnel. The economic returns from an agroforestry project are often the subject of preconceived ideas, particularly with regard to the impact of competition between tree and cultivated areas.

Planning and implementing such a system can also be complex and require a good knowledge of the trees, crops and animals involved.

Trees can also cause competition problems for water and nutrients with crops. In viticultural agroforestry, competition for light, water and nutrients has focused the attention of researchers for around twenty years now. Early studies reveal that vines and trees do not appear to compete significantly for nutrients or water, but may compete for light.

The presence of trees can increase bird predation in vineyards. Appropriate infrastructure must therefore be in place to deal with bird damage.

Finally, agroforestry may also not be suitable for all types of soils and climates. It can be difficult to find the appropriate trees and species for a given site, and it can be difficult to maintain a balance between crops and trees to avoid competition problems. It is therefore important to carefully study local conditions before implementing an agroforestry system.

Conclusion

Agroforestry emphasizes the importance of the interaction between crops, animals and trees. A synergy is then created when different aspects of the environment complement each other. Essentially, trees provide habitat for wildlife and the wildlife, in turn, controls pests. This synergy is a guarantee of a balance to be preserved, but generally requires planning, advice and technical support to succeed in every aspect of the winemakers's project.

Like all agroforestry systems, viticultural agroforestry systems require planning and management strategies in order to maximize synergistic reactions between trees and vines and minimize competitive reactions. Vitiforestry is seen today as a serious avenue for solutions to climate change, vine diseases and soil management.