Agrometeorology Discipline Hosts Inaugural Workshop on Sap Flow Measurement

Staff from the Discipline of Agrometeorology at UKZN’s School of Agricultural, Earth and Environmental Sciences SAEES) hosted a two-day workshop on the Pietermaritzburg campus under the topic of sap flow and heat pulse velocity for 60 participants from various South African universities and research institutions.

The workshop was the first of its kind in the country and was precipitated by the increased popularity in the use of the sap flow and heat pulse velocity techniques locally, and the complete lack of such training in South Africa.

According to Senior Professor of Agrometeorology at UKZN, Professor Michael Savage, sap flow techniques are methods for measuring the transpiration of woody stem tree plants and herbaceous plants, such as maize, sugar cane and soybean. In South Africa, about 67% of the total available water resources are used for irrigation. To increase the efficiency of irrigation systems, and for the preservation of natural systems, timely knowledge of water use is essential. Together with other measurements, sap flow measurements allow for the estimation of evaporation.

Savage was assisted in arranging the workshop by Professor Colin Everson of UKZN’s Centre of Water Resources Research, Dr Alistair Clulow of the Discipline of Agrometeorology, and Mr Vivek Naiken of the Disciplines of Hydrology and Agrometeorology. Presenters covered principles of sap flow on the first day, moving on to practical aspects of sap flow measurement.

Participants included interns, postgraduate students and established researchers from the universities of the Free State, Limpopo, Pretoria, Stellenbosch, the Western Cape, and Zululand, as well as the Agricultural Research Council, the Citrus Research Institute, the Council for Scientific and Industrial Research, the Institute for Commercial Forestry Research, the SA Environmental Observation Network, and the SA Sugarcane Research Institute. Honours, masters and PhD postgraduate students in the Hydrology and Agrometeorology Disciplines at UKZN also attended.

Participants scored the presentation and organisation of the workshop very highly in their feedback, and indicated that they appreciated the knowledge and experience of presenters. Many stated that the knowledge they had gained would be applicable in their research, and said the combination of theoretical and practical aspects was effective in helping them gain familiarity with sap flow theory and techniques.

Participants, who particularly enjoyed learning about installation of systems and data processing, indicated interest in attending future, more advanced workshops, on sap flow as well as on topics such as eddy covariance and surface renewal, data analysis and interpretation, scintillometry and evapotranspiration methods and more.

Savage plays a role in mentoring young scientists, academics and practitioners in his field, and views the hosting of these types of workshops as contributing towards the achievement of that aim.

He arranged similar workshops in 2016, 2017 and 2018 on different topics and hopes to conduct future workshops on topics of relevance and importance in his field.

•   Campbell Scientific Africa and UKZN sponsored the workshop.

Words and photograph: Christine Cuénod