Dennis Watson, DEPI Rutherglen
The time to start irrigation varies from season to season, but it is important to prepare for its arrival to avoid pasture production losses. Past research shows starting irrigation late incurs a yield penalty of 65 kilograms dry matter per hectare for each day delayed. With grain prices high this season this could be very valuable feed. Analysis of historic weather data provides an average date to begin irrigation. However given this an average it is just as important to know the likelihood of an early or a late start. The average start-up times for different locations across the north east is shown in Table 1. If you are risk adverse and want to be prepared, the table shows the date for the earliest one in ten years (drier side) to be prepared for. The table also shows the date for those who are optimistic and want to take a risk the year is the one in ten (wetter side) where irrigation can be delayed. If for example you are an irrigator in Corryong the average irrigation start up time is likely to be at the end of October, but ten per cent of the time this could be in late September. If you are in the Wangaratta region it might be worth starting to prepare for irrigation earlier.
|Earliest 1 in 10 years||Average start up date||Latest 1 in 10 years|
Start to get things ready to go by:
- Preparing irrigation channels (spraying, checking for wombat holes etc);
- Undertaking maintenance of pumps and motors;
- Checking foot valves;
- Fixing centre pivot wheel rut issues;
- Getting bike shift and K-line systems ready to go;
- Unblocking sprinklers and nozzles; and
- Planning fodder conservation so as not to interfere with irrigation paddocks.