Water is a precious commodity in vineyards, and soon – thanks to an innovative new research project – growers will be able to account for every drop.
Currently, most grape growers schedule irrigation using soil moisture sensing, observing vines for water stress symptoms, or based on weather and/or historical irrigation regimes.
Dr Vinay Pagay is developing new tools that will allow growers to schedule irrigation precisely based on real-time measurements of vine water status.
However, these approaches can result in either over-watering or under-watering; which in turn leads to either excessive growth or vine water stress, both of which can lower yield and fruit quality.
A new research project – led by Dr Vinay Pagay, a lecturer in viticulture and vineyard engineering at the University of Adelaide – is developing new tools that will allow growers to schedule irrigation precisely based on real-time measurements of vine water status in conjunction with UAV-based remote sensing.
The research team has developed a proximal sensing platform that uses thermal sensing to continuously measure vine water status and provide feedback to a decision support system.
The decision support system can provide semi-automated or even automated irrigation control for precision irrigation at the block or sub-block level.
‘The advantage of vine-based sensing of water status for irrigation is that it is independent of soil type and environmental conditions, as the vine integrates both elements. With the advent of low-cost microprocessors and infrared thermal sensors, this new platform has become economically feasible for growers’, said Dr Pagay.
To test the functionality of the sensor system, the team is comparing continuous plant water status sensors against established techniques for plant water status measurement.
Preliminary results from the trial suggest that using a plant-based irrigation scheduling approach can save up to one-third of seasonal irrigation without yield or grape quality penalties, compared to conventional approaches.
‘We have established an irrigation scheduling model with a cultivar-specific algorithm based on continuous vine water status data’, Dr Pagay explained. ‘Sensor data is then correlated with plant performance and productivity data to develop predictive models of vine water status.’
The sensors are part of a wireless sensor network and communicate real-time data using an Internet of Things (IoT) communication technology, LoRaWAN. This network is being used to collect high spatial and temporal scale data that will be accessible to users via a new tablet or smartphone application. The sensors are being commercialised through a start-up company, Athena Irrigation Technologies, as well as The University of Adelaide’s commercialisation arm, Adelaide Enterprise, and Tonsley business incubator, Innovyz.
Field trials are currently underway comparing conventional vs. sensor-driven irrigation on vine performance, yield, vine and vineyard water use efficiency.
Small lot wines from the treatments will be assessed for basic grape/wine composition and quality (sensory analysis). Water and energy costs for the different irrigation scheduling approaches will also be compared.
Dr Pagay said the new technologies represented an important step forward for growers.
‘By optimising water application in vineyards through these precision irrigation tools, growers can improve water use efficiency, yield, grape and wine quality.’