SATI Beyond The Bunch 1st Quarter 2026

Tools The following tools can provide spatial or temporal information, or both. They range from the bare basics to blue-sky technologies.

For growers who prefer traditional methods, rest assured that new technology isn’t required for precision irrigation and fertilisation. And for those who can’t wait to send armies of satellite-guided robots into their vineyards, be warned that new technology isn’t a substitute for doing the right thing to the right degree at the right time.

Seeing is believing Manual assessment of soil moisture (the squeeze test) is old-school but highly effective. Soil samples are collected at three depths (0–20 cm, 20–40 cm, and 40–60 cm). A handful of soil is squeezed, and the moisture content is rated on a scale of 1 (too dry to hold together) to 5 (water drips out). Samples can be taken with soil augers or from profile holes. Soil augers are quick to use, but manual augers are not suitable for very rocky soils. Profile holes take a little longer but present an opportunity to evaluate root development, which should be assessed monthly in all blocks. Moisture must be assessed at least weekly in all blocks, just before scheduled irrigation events. Where blocks have highly variable soils, evaluate moisture separately in each soil type and in areas of different vine vigour. Keep in mind that weak vigour can result from too-wet or too-dry soils. Manual assessment of soil moisture primarily provides temporal data relevant to irrigation scheduling. However, soil augers and profile holes are also valuable tools for collecting multiple samples across a block to evaluate spatial variability.

Soil probes, stem water potential, and weather stations

Soil probes are usually permanently installed and automatically log moisture. They can provide data to inform scheduling decisions if correctly installed and working properly. Probes are useful for assessing the depth to which a known amount of water will infiltrate. Like any complex technology, probes can fail (for example, due to flat batteries, disturbances, break ages, or vandalism) or produce misleading data (for example, due to calibration errors or the wrong placement within a block or relative to emitters). Growers should never rely on probes alone when scheduling irrigation. The tools discussed so far all measure soil moisture. It’s also possible to measure the plant’s moisture stress directly with stem water potential. The technique is most often used in research, but growers can also employ it to relate plant stress to soil moisture levels measured with probes or squeeze tests. More details on stem water potential are available in the resources listed under Further reading. In the future, stem water potential may become mainstream as technology is developed to enable automated measurements in commercial vineyards.

DEWALD KIRSTEN | LUCENTLANDS

BEYOND THE BUNCH • 10 • QUARTER 1 • 2026