Impact of biochar application on plant water relations in Vitis vinifera (L.)

•Crop management strategies play an important role in the soil water content.•The impact of biochar application on soil–water relations and on Vitis vinifera water status was assessed.•Two rates of biochar application in two years were considered.•Biochar addition increases the soil water-holding capacity and plant available water content.•Biochar addition substantially affected ecophysiological parameters of V. vinifera.

Soil water status plays an important role in growth-yield and grape quality of Vitis vinifera (L.). In some cases, periods of moderate water stress have been indicated to exert a positive effect on the quality of grape production. However, prolonged water stress may have a strong negative affect grapevine photosynthesis and grape yield, especially in dry Mediterranean environments. Biochar is a co-product of a thermochemical conversion of biomass that is recognized to be a beneficial soil amendment, which when incorporated into the soil increases soil water retention. We investigated the effect of two rates of biochar application (22 and 44 ton ha−1) on plant water relations of V. vinifera in a field experiment in central Italy. Biochar obtained from the carbonization of orchard pruning waste was applied to the soil over two consecutive growing seasons. The treatments did not show a significant increase in soil hydrophobicity. Moreover, soil analysis and ecophysiological measurements indicated a substantial relative increases in available soil water content compared to control soils (from 3.2% to 45% in the 22 and 44 ton ha−1 application rates, respectively) and in leaf water potential (24–37%) during droughts.