The word sustainability and its associated ideas of environmental, economic and social impact have quickly become standard language in the wine industry, and as the concept has matured so too have industry targets. Australia and New Zealand have both included net-zero carbon emissions in their strategic plans for 2050 and vineyards on both sides of the Tasman have been investigating biochar as one approach to carbon emission reduction as well as soil amelioration.
The centuries-old technique is attributed to the Indigenous people of the Amazon, where it is thought layers of food waste and charcoal from cooking fires built up to produce a highly productive, fertile topsoil. Known as terra preta, meaning ‘black earth’ in Portuguese, these soils were dark in colour and rich in carbon content. Today, this type of charcoal, or biochar, is produced by burning biomass in a low or no oxygen environment. The burn process, known as pyrolysis, yields a highly porous, honeycomb-like textured charcoal that can be milled for use in the vineyard. In order to fully exploit potential benefits associated with improved soil health, biochar may be mixed with a nutrient dense solution such as compost or manure before application.