One part of how we practice biodynamics at “Black Smiths” is that we try to treat our vineyards as a closed loop as much as possible. We minimize the materials we bring in and we try to recycle our farms resources back into our own land as much as we can. This is not about being isolationist or exclusionist its about being self-sustaining. In this way, when we see skins and pips etc after grapes are pressed we dont think waste we think resource. We look at the gorse, broom, grasses and willows that grow in and around our vineyards the same way far from being weeds these materials are a valuable resource we put back into the land through our composts.
Composting isn’t new and its certainly not unique to “Black Smiths”, but there is a fundamental difference in attitude (and compost quality) between composting grape pressings as a means of ‘waste disposal’ and using these materials as a part of high quality compost. It comes down to a different objective; getting rid of skins etc vs. aiming to make the best compost possible.
Grape pressings have a low pH and are very high in Potassium and Nitrogen, so not ideal as the main component of compost, which benefits from greater diversity of materials and, especially, more carbon. High nitrogen means very hot compost, reducing some of the microbial diversity we’re looking for.
We will make approximately 400 tonnes of compost at “Black Smiths” this year – about 20% grape marc, 20% old hay specifically grown for this purpose plus some cut from vineyard headlands, 20% old woodchips, 20% fresh woodchips, 20% cut grass all layered together with a slurry of cow manure, lime and rock minerals. As well as making different compost mixes, each seeded with biodynamic preparations, we have trained staff to analyse the composts under a microscope to ensure were getting the desired attributes in each mix.
We use composts in different ways. Some is spread to condition soil and target nutrition to young or struggling vines and olive trees and some is used in our vegetable gardens and orchard. Each year, about 10 tonnes of woody, fungally rich compost, is mixed with water, aerated (to keep the bugs alive) to make about 300,000 litres of compost tea which is sprayed over our plants and onto the vineyards putting back into the land, some of the goodness it has provided, keeping natures cycle going.