Use of Winery and Animal Waste as Fertilizers to Achieve Climate Neutrality in Non-Irrigated Viticulture

Carbon (C) storage and capture in soils along with a reduction of farm-related GHG emissions are key processes for climate change mitigation. There is a growing global interest to assess the C sequestration potential of important crops, such as vines (Vitis vinifera) due to their importance to the global economy, but in many cases emissions due to inputs production and grape quality are neglected. In this work, the potential of Mediterranean viticulture for GHG emissions mitigation and C storage in biomass and soil is examined, using as a model the indigenous cultivar Xynisteri in vineyards on the island of Cyprus. The C balance was determined at vine and vineyard levels, as well as vine-grape quality attributes, under different management practices. A tool for GHG emissions estimation in vineyards was produced, based on the Cool Farm Tool and the relevant literature for perennial crops. The tool was designed to be easily used by the farmers and support the implementation of C farming, using the LCA approach and also incorporating nutrient cycling (e.g., C, N). Our results show that existing conventional viticulture could be easily transformed into zero-emissions viticulture via smart agricultural practices such as reducing N fertilizers, in line with the Farm to Fork Strategy, using less fuel while adopting no-tillage and maintaining field margin vegetation at the farm level. This study stresses the importance of the LCA use when dealing with C sequestration projects. It shows that a reduction of farm inputs could lead to a (non-irrigated) vineyard low-inputs system supporting firstly, a lifetime C storage equal to 25.124 tons CO2-eq ha-1 or 0.837 tons CO2-eq ha-1 year-1 and secondly assisting in climate change mitigation and adaptation for Mediterranean viticulture. This approach could be used for the design of eco-schemes related to C farming, under the new Common Agricultural Policy (CAP).