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SARDI takes the lead in irrigation research
Optimum production in irrigated horticulture is resulting from research conducted by SARDI in South Australia’s Riverland.
The SARDI research provides guidelines for irrigators on using soil solution samplers to manage precision fertigation.
Precision irrigation involves applying water in controlled amounts to closely match crop requirements, ensuring that plants water needs are met including where appropriate controlled water stress.
SARDI Irrigation Research Scientist Mark Skewes said “Fertigation is an ideal partner to precision irrigation, as it applies fertilisers through the irrigation system directly to the roots of the plants.”
While there are many tools for monitoring soil water content, there is not the same level of monitoring available for fertiliser concentrations in the soil. In order to address this SARDI’s research monitored fertilisers in the soil solution using SoluSamplers (developed by SARDI and licensed for distribution through Sentek Pty Ltd).
Mr Skewes, who is based at Loxton Research Centre, presented the results of the monitoring to the recent Irrigation Australia Limited (IAL) Conference in Launceston, Tasmania, and discussed the appropriate use of soil solution monitoring to manage precision fertigation for optimum production in irrigated horticulture.
“The results presented demonstrated the benefits of soil solution monitoring for management of fertigation, in particular highlighting periods when fertiliser inputs exceeded plant uptake, leading to leaching of fertilisers beyond the rootzone of the crop,” Mr Skewes said.
“However, the data presented also suggests that it is not possible to set critical concentrations of fertilisers, rather fertiliser management should be base on analysis of the trends in concentration at various depths in the soil.”
Mr Skewes also presented three poster papers at the conference, relating to research into managing drought in permanent horticultural crops. These included an analysis of the drought tolerance of citrus rootstocks, which indicated that two of the most commonly used rootstocks in replant situations, Troyer Citrange and Swingle Citrumelo, are in the most drought tolerant group of rootstocks, providing confidence for citrus growers in the face of expected future challenges in water availability.
The other two posters reported on the use of multiple water meters within a trial, to give high quality information about irrigation applications to each treatment, and the use of the Irrigation Recording and Evaluation System (IRES) software for managing research trial data.
At a workshop on drip irrigation, convened by the IAL’s Drip Special Interest Group in conjunction with the conference in Launceston, a web page which SARDI helped develop and is dedicated to providing high quality information about drip irrigation, was launched.
A detailed manual titled ‘Understanding Drip Irrigation’ which covers all aspects of drip irrigation was also launched. Copies of this manual are available from the IAL.
Mark Skewes assesses partial cover sprinklers as a response to water shortage in a citrus orchard.
