Compost is undeniably a pillar of fertility in organic farming, but in biodynamics, its role takes on a far deeper dimension. At Château Cazebonne, our compost is not merely a simple soil conditioner; it is the pulse of our soil, an activator of life that we craft with meticulous care. It embodies our commitment to nurturing the land so that it may, in turn, nourish the vines and express the richness of our terroir.

Its preparation follows rigorous principles, designed to orchestrate harmonious decomposition and imbue the compost with essential life forces. It all begins with the diversity of raw materials: we carefully incorporate elements sourced directly from our estate, such as grape pomace after pressing, shredded vine shoots after pruning, and cuttings from cover crops. These are supplemented with cattle manure from local farms that also operate organically or biodynamically. This wealth of components is the key to stable humus teeming with life.

Building the compost pile is a crucial stage. We methodically alternate layers of carbon-rich brown matter (such as vine shoots) with nitrogen-rich green matter (such as fresh grass or manure). This layering guarantees optimal aeration, indispensable for the composting process to proceed smoothly, and maintains ideal moisture levels.

Dynamic compost preparations

The distinctive feature of biodynamic compost lies in the addition of the six compost preparations (numbered 502 to 507). Once the pile is built, we insert these precious preparations. Each is crafted from a specific medicinal plant – yarrow, chamomile, stinging nettle, oak bark, dandelion, valerian – and subjected to a unique preparation process, often using animal organs as sheaths and conduits. These preparations act as true catalysts, guiding the decomposition processes, stabilising fundamental nutrients (notably nitrogen and phosphorus), and imbuing the compost with organising, revitalising forces that enhance its effect on the soil.

• Preparation 502 is based on yarrow, promoting the assimilation of potassium and sulphur.
• Preparation 503 uses chamomile, stabilising nitrogen and supporting calcium processes.
• Preparation 504, made from stinging nettle, stimulates microbial activity and iron assimilation.
• Preparation 505, made from oak bark, balances pH and reinforces calcium-related processes.
• Preparation 506 incorporates dandelion, stimulating silica-related processes and promoting potassium.
• Preparation 507, from valerian, acts upon phosphorus processes and the compost's vitality.

After several months of maturation – a process that can take from six months to a year, punctuated by occasional turnings to homogenise decomposition – the biodynamic compost is ready. It takes the form of fine humus, dark in colour with a pleasant scent evocative of the forest floor. Spread sparingly across our parcels, it works in depth, reaching far beyond simple nutrient input. It also complements the practice of Maria Thun compost, which we use alongside the astronomical calendar for vineyard tasks:

• It intensely stimulates soil biological activity, encouraging the proliferation of beneficial microorganisms and earthworm activity.
• It significantly improves soil structure, optimising water retention capacity and resilience to climatic variations.
• It releases essential nutrients gradually and in a balanced manner, providing the vines with steady nourishment tailored to their needs.
• It strengthens the overall resilience of our agroecosystem, contributing to a natural and sustainable balance.

Biodynamic compost at Château Cazebonne

This compost is a decisive factor in obtaining healthy, expressive grapes capable of conveying the typicity of our Graves terroir with remarkable fidelity, even for our forgotten grape varieties. Château Cazebonne thus dedicates a fundamental part of its work to the life of the soil. It is thanks to this commitment and the valuable support of the many wine lovers who have embraced our biodynamic wines that we can pursue our mission: replanting ancient, forgotten grape varieties in Bordeaux, reviving the region's ampelographic richness, as highlighted by Jean-Baptiste Duquesne in "Bordeaux, une histoire de cépages".

Our approach is part of a quest for holistic coherence, where every action, from revitalising soils to dynamising preparations, contributes to the harmony of the ecosystem. To learn more about the fascinating history of Bordeaux grape varieties, we invite you to download our book "Bordeaux, une histoire de cépages". To test your knowledge, take part in our wine quizzes, and of course, discover the expression of this work in our biodynamic wines, available in our online shop.