Land and Water Link

April 2003

Making the Most of a Trickle

Irrigators can now make better use of trickle River and Irrigation Hydrology to water and fertilise their crops with the release of a new irrigation tool called WetUp.

Developed by CSIRO and the Cooperative Research Centre for Sustainable Sugar Production, with funding from Land & Water Australia's National Program for Sustainable Irrigation, WetUp encourages growers to program their trickle systems according to local conditions.

'Irrigators know there can be large variation in soils and crop water use. The challenge has been to understand this variation and work with it rather than against it', says CSIRO Land and Water researcher Dr Keith Bristow.

'By probing the soil and measuring soil water behaviour at different depths and in different soil types, we've identified the soil properties controlling wetting. Going one step further, to make this information readily available to those who need it, we have developed a software tool to show irrigators how variable wetting in soils can be.'

'The result is WetUp – a software package for irrigators, designed to help them understand how important it is to customise the design of trickle systems for specific paddocks', explains Dr Bristow.

'WetUp, which is available for download from the web, will help irrigators understand more about their soil and the way water moves through specific soils.'

The package is capable of illustrating wetting patterns for 29 individual soils, covering a wide range of textures and soil hydraulic properties.

According to Dr Peter Thorburn from CSIRO Sustainable Ecosystems, 'For trickle River and Irrigation Hydrology to deliver improved water and nutrient use efficiency, distance between emitters and emitter flow rates must be matched to the soil's wetting characteristics and the amount and timing of water to be supplied to the crop'.

'Broad soil texture ranges are usually the only information related to soil wetting used in current trickle system designs. However, this information is inadequate. Soil structure, which is not represented by these broad textural ranges, can dominate water movement, and site-specific information about soil structure and its impact on water flow is required.'

Chair of Land & Water Australia, Bobbie Brazil, puts WetUp in perspective: 'There has been a lot of pressure, particularly in the current water debate, for farmers to switch to trickle irrigation, but it's not always viable, productive or even more efficient in terms of water use'.

This research, and WetUp in particular, means that those irrigators who invest in trickle systems, will be better placed to implement efficient and sustainable systems.

The WetUp product is the result of collaboration between CSIRO Sustainable Ecosystems and CSIRO Land and Water, the CRC for Sustainable Sugar Production and Land & Water Australia's National Program for Irrigation Research and Development.

The WetUp software package is available for download from the web:
www.clw.csiro.au/products/wetup/

For further information

Contact
Dr Keith Bristow
Ph: 07 4753 8596