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Location

Moonyanco is situated on the northern bank of the Yanco Creek, 20km east of Conargo in the heart of the Riverina, and has been owned by the Gordon family since the late 1980s.

Farming enterprise

The property has always been run as a mixed sheep, cattle and cropping enterprise. The Gordon family runs merino sheep for wool production, beef cattle and have a winter and summer cropping program that involves rice, soybeans, mung-beans, canola, chick peas and wheat. Of the 6,200ha that the property covers there is approximately 800ha layed out to flood irrigation.

Project description

The installation of a lateral spray irrigator over 300ha of the irrigation country has been a major and successful development for the Gordon farming business.

The old areas of contour irrigation had become uneconomic, both in terms of the volume of water required to irrigate and the labour and management involved. The area is very flat and the bays were so large that they just became too hard to manage. Under the old flood method bays took a long time to fill and time and labour required to manage the movement of water through the bays was becoming unmanageable. The Gordon family was faced with a choice of either converting the area to border check irrigation with a recycling system or making the move to spray irrigation technology.

The On Farm Irrigation Efficiency Program provided the assistance required to make the move into a more efficient form of technology affordable. The Gordon’s lateral move irrigation system is innovative in its approach. The Reinke lateral is the largest lateral spray system available, measuring 1,208m in width and traversing a length of paddock 2,500m long (this equates to an area of 300ha). It has a range of features aimed at minimising soil compaction and allowing it to move easily over the clay loam soils on site, including three-wheel towers, boom-backs which apply water behind the towers and 13x38 high flotation tyres. The system is designed to deliver a flow of 25ML/day which provides sufficient capacity to irrigate summer crops.

Most importantly the system is designed to work in tandem with a flood irrigated system. The lateral channel is designed to allow the Gordon’s the option to flood irrigate the paddock, filling the soil profile in early summer and then relying on the spray system to keep the soil profile topped up during the hottest summer months. It is difficult in the hot and dry Riverina conditions to rely on spray irrigation alone to water a summer crop from establishment through to harvest.

If a fall back to flood supplementation is required this lateral irrigator has a flexible wheel configuration which allows it to walk over the flood irrigation banks which have been retained.

The Gordon’s have cropped under the lateral in winter 2013 with wheat sown in the top two thirds of the irrigated area and the bottom third of the paddock to chick peas. They did not sow a summer crop.

It is unlikely that the whole 300ha under the irrigator will be sown to one crop type at any one time, preferring to use the flexibility it provides to grow a diversity of crop types. In summer it is likely that only 100ha of irrigated crops will be established to ensure that the spray system can maintain sufficient water to take the crop through the summer with optimum yields.

Whilst the Gordon’s have only had the benefit on one season of use under spray they are confident that the estimated water savings in the order of 3ML/ha will be realised by the move from flood irrigation to spray.

On a cautionary note Tom Gordon has pointed out that the energy use associated with spray irrigating is very high when compared to the old flood system. Energy is a cost which must be factored in by anyone planning to convert their system from flood based irrigation.

The Gordon’s have identified that they will gain the most benefit from their spray system in years when water is scarce and crop prices are high. It revolves around using the irrigators on optimum crops and yields at optimum times. This is new thinking around a new approach to irrigation farming in the region. It will soon become common knowledge in the industry – but pioneering projects such as these are setting a formidable example on a steep learning curve.

report card

  • Greater flexibility to grow a range of winter and summer crops
  • Water Savings of 3ML/ha are likely to be achieved.
  • Lower labour requirements
  • Higher yields using less water, particularly in years when water is scarce and allocations are low.
  • The trade-off between water savings and energy costs need to be managed closely.