Vineyards in regions characterized by a lack of soil moisture, limited natural irrigation and low rainfall are often under significant water stress for the plants. These regions usually have arid or semi-arid climates, which can be a challenge for grape production. Some of these regions where vineyards are particularly stressed due to these conditions are located in Southern Mediterranean latitudes, Central Coast of California, Central Chile, South Africa, South Australia and South Argentina.
As plant-available water becomes more of a problem even in previously well-supplied regions, mapping soil properties can provide information on soil texture, moisture content and mineral composition and help to understand these variations in
order to tailor management measures to specific areas within a vineyard.
The moisture content of the soil is a critical factor for the health of the vines and the quality of the fruit. The electromagnetic induction method provides information about the moisture content of the soil and thus helps the responsible winemakers
to implement efficient irrigation strategies in the vineyards and to avoid problems such as overwatering or drought stress.
The Topsoil Mapper enables rapid non-invasive data collection on large areas even in difficult terrain. The picture shows the use of the Topsoil Mapper in a vineyard in Klosterneuburg/Austria in a south-exposed, mineral-rich site (alternating marl, slate, limestone and sandstone) on very steep terrain with a slope of > 36 %.
The Topsoil Mapper was used on this experimental vineyard, where different artificial irrigation strategies are being tested. The sensor was used to monitor plant available water under controlled irrigation conditions during the growing season.
Different irrigation strategies are clearly reflected in the ECa (apparent conductivity) data collected, which are shown in the
Areas with very low plant-available water are shown in red, while green and blue coloured areas have a higher water supply.
Clearly visible are the headland areas - in the north-east and south-west of the vineyards - where there is no irrigation and compaction is high due to the intensive, heavy machinery work. The rows starting to the east are drip irrigated, with watering reduced to a certain percentage in every third row. From row 9 onwards, the plants are only supplied with natural irrigation. As the available water changes, this is reflected in the ECa values, which are shown in the colour-coded map. For the case study area, the ECa mapping is converted into a moisture map of the available water in the main root zone of the upper soil layer (0 - 30 cm) by insitu calibration.
Overall, electromagnetic induction provides valuable insights into soil properties and moisture distribution, making it a versatile method for soil mapping in viticulture.
It enables winemakers to make informed decisions that optimise grape production, improve fruit quality and promote sustainable practices.