The Isis milling district around Childers is one of Queensland’s driest cane growing districts. About a metre of rain can be expected in a good year and farmers depend on water purchased from SunWater to irrigate their crops.
Working closely with growers, CANEGROWERS Isis and Isis Productivity Limited are playing a key strategic role in the industry-wide drive for improved water use efficiency.
Part of that cooperation is an ultrasonic water flow meter purchased using funds made available through the Queensland Government’s Rural Water Use Efficiency – Irrigation Futures program.
The meter uses technology more commonly found in a medical imaging centre, an ultrasound system, to measure the flow of water.
Two transducers are covered in gel and clamped to an irrigation pipe where they pick up particulate flow in the water. By measuring particulate flow, it’s possible to determine the rate of water flow within the pipe.
Coupled with new pressure gauges that were also purchased with RWUE-IF funding, it’s possible to obtain accurate data to streamline irrigation systems to minimise pumping requirements and therefore energy use.
“The concept behind it is to see where losses occur in the system,” agronomist Andrew Jakins explained. “We can take pressures within the pump shed itself, at varying points on the inlet and outlet side of the pump and see where any losses might be occurring in the system.
“Once we get into the paddock we can look at pressure readings at the irrigation equipment, such as a centre pivot, and see what loss is occurring between the pump and the delivery method at the other end.”
Making more efficient use of water and electricity is crucial from an economic perspective for growers whose margins have been cut by the rapidly rising cost of electricity.
“The situation is that electricity prices have risen more than 120% in the past seven years and that’s not tolerable for growers,” CANEGROWERS Isis manager Wayne Stanley said. “Rain usually provides 50% of the crop’s water requirement here but that can vary season to season depending on the climate.”
The team from Isis Productivity Limited is busy visiting farms all over the Childers district to run tests on irrigation infrastructure using the ultrasonic flow meter.
With an accurate picture of the irrigation system's performance, decisions can be made about straightening irrigation lines, moving to low pressure systems and smaller electric motors.
See the ultrasonic water flow meter in action on Bevan Manderson's farm, and his low pressure pivot, in this CANEGROWERS Virtual Bus Tour video.