Milking the Weather – Climate Update

Soil moisture monitoring, a hot, dry winter, and El Nino were topics of discussion in the winter Milking the Weather webinar. Moving from a hotter, dryer March to May period, climatic conditions could be stabilising as we come into winter.

Milking the Weather is a quarterly seasonal outlook primarily focussed on the dairy industry’s pasture production needs.

The Milking the Weather winter webinar was recorded and can be accessed at (Link - Password: Milking3)

Soil Moisture Monitoring Project Update

Soil Moisture Monitoring (SMM) Project lead, Dale Boyd reported on the expansion of the SMM project from dry-land cropping areas to dairy pasture sites. Soil moisture capacitance probes have been installed at 17 pasture monitoring sites across Victoria. Paired probes have been installed at a range of pasture sites, comparing permanent pasture and fodder crop conditions at each site. Due to seasonal conditions, several of the sites have been able to establish soil moisture adequacy ranges, however several of the northern Victorian locations have still not established saturation point.

With the hot, dry summer and scarce rainfall events, all sites showed considerable drying of the profile. The areas which received scattered summer and early autumn rainfall events showed limited infiltration below 10cm, however the May rainfall events observed in Gippsland and South West Victoria have begun to infiltrate to 50cm.

Early observations from the project have shown the impact of crash-grazing on soil moisture, with plateaux observed in soil moisture levels after grazing events. The Yarram location gave a comparison between perennial ryegrass and summer-active prairie grass. The deep roots of prairie grass allowed for considerable drawing of deep moisture beyond 80cm. Rainfall events on prairie grass pastures were rapidly taken up and lower levels of infiltration observed that the semi-dormant perennial pastures.

May rainfall events in western Victoria have led to soils at the Jancourt monitoring site now at approximately 50% of capacity.

Climate Outlook

Dale Grey, Climate Scientist from Agriculture Victoria reported to the Milking the Weather webinar group that the last of the weak La Nina indicators are easing off in the Pacific Ocean. While warmer water is pushing up towards the Pacific coast of South America, which can be a precursor to El Nino conditions, most models are indicating that an El Nino event is unlikely to develop at this stage.

The unusually high pressure conditions which held over the Bight, blocking much of the autumn rain from reaching South Australia and Central NSW is looking to ease, with models generally indicating average to slightly dryer conditions over winter, with equal chance of wet, average or dry conditions developing. Temperature models are suggesting average to warmer than average conditions for the Surf Coast and surrounds over winter, which may favour winter-active crop growth where soil moisture allows.

While there is little confidence in longer term projections at this stage, there are no strong dry signals for spring. There is weak consensus between models, however El Nino conditions may develop. Temperature models are tending towards an average to warmer than average spring.

To register for future Milking the Weather webinars visit: agriculture.vic.gov.au/agriculture/weather-and-climate/milking-the-weather

A Victorian Winter Climate update webinar featuring Dale Grey will be held on Monday 18th June. Register for this webinar