# A Review of the Potential Climate Change Impacts and Adaptation Options for European Viticulture
## 5 Climate Change Adaptation Strategies
### Short-Term Adaptation Strategies
#### 5.1.3 Irrigation  
Records of grapevine irrigation date back to ancient times (2900 BC) [178], and is a common practice in many countries, especially in the \"New World\" (e.g., Australia, USA). Even in countries where grapevines are traditionally rain-fed (e.g., France, Spain, Portugal, or Germany), irrigation has increasingly been implemented and local guidelines have slowly been adapted for this practice. However, for the production of high-quality wines (e.g., Brunello di Montalcino in Italy or Port Wine in Portugal), the current regulation only permits \"rescue\" irrigation.  
Irrigation is used to improve and standardize crop yield and quality, whenever rainfall is too low to meet the defined grapevine water requirements. The management of vineyard irrigation is based on deficit irrigation (DI) strategies (e.g., regulated deficit irrigation, sustained deficit irrigation, partial root drying) to take advantage of the relationship between grapevine water status and the yield/quality [179]. Taking into consideration these strategies, drip irrigation is generally implemented as the most efficient water saving method [180; 181], although sprinkler and furrow irrigation systems are still being used [182]. The implementation of DI strategies can be used to enhance water savings, which is particularly needed in wine regions with greater water deficits [183]. Furthermore, these cultural practices may be maximized with automated and smart irrigation (with real-time control and optimisation) systems [184].  
A common methodology for DI implementation consists of the selection of a defined percentage of the computed crop evapotranspiration [185]. However, soil and/or plant water status indicators and respective thresholds should be used, preventing a continuous decrease in root-zone water content. Although measurements of soil water content (or soil water potential) may roughly determine the amount and the timing of irrigation, strong under- or overestimations may occur because the real depth of the root system is not taken into account. If this is the case, direct plant water status indicators are particularly useful [186; 187]. Among those indicators, stem and leaf water potential have been extensively used. More recently, other techniques, such as trunk diameter variations and sap flow measurements have been implemented, with the advantage of possible automation [188; 189].  
Using a deficit irrigation technique, no yield reduction was observed for Godello grapevines [190]. Improvements in quality attributes were also found using these strategies on other varieties [191; 192; 193]. Hence, a sustainable water use strategy together with available water resources can be quite advantageous and cost-effective for the growers [194]. Nonetheless, the assessment of the real benefits and costs (including terrain factors, water distribution systems, technological options, on-farm _versus_ catchment or basin-scale water savings, and socio-economic conditions) for implementingirrigation under future climates is critical for the adoption of these adaptation measures [184; 195], particularly in Southern Europe, where water availability is predicted to diminish [10; 112].