Deniliquin Pastoral Times
Getting the best out of your overhead irrigator
ays are getting longer, and crops and pastures are growing remarkably well. Even though most have good reserves of subsoil moisture, crops and pastures with large biomass (and therefore yield prospects) will start to quickly use moisture as we move into spring.
To capitalise on this good yield potential, and prospects for excellent prices for most commodities, it is critical irrigators keep an eye on soil moisture levels, and use the tools they have at their disposal to ensure plants don’t become moisturelimited.
It remains critical that irrigators get the most investments (and the water they are applying).
For those with overhead (centre pivot or lateral move) systems, doing some simple checks of how your machine(s) are operating will ensure you make ‘every drop count’.
Simple things to do include:
DInspect your irrigator’s structural integrity
Ensure your oil and grease points are serviced
Check and service your drivelines, couplings and gearboxes
Make sure your control systems, automatic shutdown and wiring are in sound working order
Check machine alignment, and any guidance arms or cables
Check the pressure of each tyre – correct tyre selection and pressure can help minimise wheel rutting supposed to
Measure and check your machine’s calibrations and settings are in place
Replace worn or broken sprinklers and pressure regulators, and check the operating pressure at the pump, and middle and end of the machine.
Apart from mechanical servicing, the key areas that affect your irrigator’s performance are the operation of your sprinklers (and pressure regulators) and the operating pressure of your machine.
There is a rule of thumb that says your sprinkler package typically accounts irrigation performance. The bottom line is, if your current sprinkler pack is not doing the job, or is based on ‘old’ technology, a new sprinkler package can be a very wise investment.
Operating your machine at too high a pressure is costing you money (diesel or electricity), whereas too low a pressure often means not enough water is being applied to your crop. Make sure you are operating in the ‘sweet spot’ for your particular system; buy a good pressure gauge and regularly check operating pressures. machine, and ultimately, the crop being irrigated:
1. Application rate - the depth/volume of water being applied.
Application uniformity - how evenly water is applied across the length of the machine. plants to use.
These can be checked with a ‘catch can’ test, where ‘cans’ are placed across the length of the operating machine, and the volume in each subsequently measured. The results can be used to work out the application rate, and how uniformly water is being applied.
If you have done all the checks and everything is working as it should, you should also do some form of soil moisture monitoring. This will help you match plant water demands to your application rates and help maximise productivity. operating, to check that everything (both crop and machine) is performing as it should. If you don’t monitor and check what your system is doing and how it is
Further information on conducting tests on centre pivot and lateral move irrigators can be obtained by contacting your supplier, irrigation professional, or speaking with me, by contacting Murray Local Land Services in Deniliquin.