In Tuscany, central Italy, grape cultivation and wine production (i.e., Chianti DOCG, Brunello di Montalcino) are farming activities appreciated worldwide.

Differently from the past, irrigation is allowed to meet the intense physiological stress that may occur during seasons affected by the increasing climate variability, in order to guarantee quality product and hence high market profitability in many vines areas.

Most vineyards are located in fields along sloping hillsides, where ground slopes and soil characteristics may vary greatly within the same cultivated area. Such situation requires well designed and assembled micro irrigation systems, as well as proper irrigation management due to the three dimensional spatial variability of soil hydrological characteristics.

Water supply according to the variable rate application (VRA) approach, typical of precision farming, requires that both system performance and soils properties are well known, since they affect the application efficiency (AE) of irrigation water.

Soil characterization, in space and depth, is allowed by different approaches. Sampling carried out according to statistical distribution methods is time and resource consuming. In order to get similar or better accuracy with minimal soil samples, the Automatic Resistivity Profiling (ARP) technology can be profitably used. ARP allows rapid surveys of the spatial distribution of different soil layers, namely the vine active root zone profile, through the Soil Electric Resistivity (SER) properties. Supported by GPS technology, 30,000 measured values per hectare are provided. Resistivity maps referred to different layers (i.e., from 0 to 150 cm) are yielded by the ARP technology. Since SER is related to the clay content, maps of clay distribution within the field can be supplied in real time. Field splitting according to in-field resistivity variations can help the assessment of soil sampling sites.

The settlement of irrigation sectors or other tricks able to match high AE can be arranged, affecting seasonal water and energy use as a consequence.

Simulations were carried out in a typical Tuscan wine-growing environment. Depending on basic soil sampling information and assuming the target efficiency of a design-supported (i.e., by the Ve.Pr.L.G.s2008 support tool) drip irrigation system equal to 95%, AE ranged from about 60% to 90%. Under ARP information maps, the lower threshold of AE was shifted up to about 80%, allowing improved overall system performance and resource (water and energy) use.