Better Frost Decisions Issue 4

ISSUE 4 | JUNE 2022

BETTER FROST DECISIONS Knowledge to inform grower and adviser decisions for pre-season planning, in-season management and post-frost event responses

IN THIS ISSUE Seasonal outlook Activities in the region New frost resources

Cold Mallee morning at seeding

Outlook for frost this coming Spring

WELCOME

Peter Hayman and Dane Thomas, SARDI Climate Applications Short answer: If the negative Indian Ocean Dipole continues to develop and remains for the coming season, we have increased chances of a wetter spring with more cloud cover, slightly cooler days and warmer nights. While the warmer nights might lead to fewer frosts, the risk of late frosts remain rare but damaging events. Perhaps an even shorter answer is that we don’t know.

Forecasting frost in the coming week, the coming season and the coming decades The difference between short term weather, seasonal climate and climate change is primarily due to time. Almost all farmers and agronomists are very familiar with weather forecasts, and many have a collection of forecasts tools / websites on their phone that they check throughout the day.

Although it is possible to get weather forecasts beyond the coming week, these are nowhere near as reliable as the forecast for rain and temperature over the next three to five days. At the other end of the time scale, climate change refers to changes in the climate such as increased temperatures that can be detected over decades. Seasonal climate refers to the coming months and answers the question “what is the likely rainfall and temperature for the spring of 2022?”.

Continued....

This is our first issue for the year and we investigate the weather outlook to see how the season is shaping up in terms of the rainfall for 2022.

Will a wetter Spring mean less frost for the year ahead?

We also catch up with AIR EP to learn about the new frost demonstration site at Tooligie Hill, on the border between central and lower Eyre Peninsula.

In our latest podcast we talk with Mallee farmers Andrew Thomas, Travis Flight and Jock McNeil to learn how they manage frost.

Plus details on PA mapping of frost from Jess Koch and Upper North Farming Systems.

Next issue due August 2022.

Weather is forecast by using today’s atmosphere to predict tomorrow’s atmosphere. The synoptic conditions that lead to radiation frosts in southern Australia are relatively well understood. These include the position of the high-pressure system, the inflow of cold and dry air from high in the atmosphere and well south of Australia.

What is the impact of IOD on rainfall in South Eastern Australia?

Farmers in frost prone regions will talk about feeling the drop in temperature as the sun goes down on a crisp, still clear night. It is almost as if you can feel any warmth being sucked away to outer space. Predicting that we will have a very cold night, is obviously easier than predicting the exact temperature at a point in a paddock.

Weather forecasts use the state of today’s atmosphere to predict the sate of the atmosphere in the coming days.

This process of measuring the evolving weather is often shown in weather maps which indicate the movement from west to east of high and low pressure systems.

Sometimes these maps will show a rain front 7 or 8 days in the future, but most farmers know to check the outlook in the coming days. Unfortunately, weather maps lose their accuracy around 5 to 7 days and are meaningless more than 10 days into the future.

To go beyond the coming weeks to the coming month and season we rely on seasonal forecasts that are largely driven by patterns in ocean temperatures. There is more energy in the top metre of the ocean than in the whole atmosphere. The patterns of ocean temperatures change over months rather than days.

While all the models are pointing to an IOD developing, it could be that they will all be wrong. It is worth following the climate drivers through June as the confidence from the models will improve through this time. The Bureau of Meteorology site and the AgVic Fast Break will provide updates on the developments of the climate drivers.

https://climatetool.forecasts4profit.com.au/

Figure 2 shows a series of pie charts for August to October temperature.

If we were to include all years in the historical record, the pie chart would show equal chance of red (driest third of years), yellow (middle third of years) and blue (wettest third of years). This represents the risk that a farmer is faces with without the forecast.

A negative IOD does not guarantee a wet spring, but it increases the odds of the blue portion from one third to about 60%. The chance of a dry spring is reduced from one third to below 20%.

Climate Driver Update (bom.gov.au) accessed 9th June 2022.

Continued....

Although there are differences between locations, the pattern is consistent across the region. This is what we might expect from a climate driver like IOD which is comparing the temperature of water on the eastern (Africa))and western (Indonesia) side of the Indian Ocean.

Photo T Morgan

What is the impact of IOD on temperature as well as rainfall.

For this data we used high quality temperature sites that are relevant to the SE Australian grains belt; these included Ceduna, Kyancutta, Snowtown, Nuriootpa, Nhill, Mildura and Kerang. We analysed each site separately and then averaged the seven sites for a summary.

We can draw the following conclusions about the IOD. 1.These sites confirm the shift in rainfall with negative IOD springs, are 21% wetter than average with 13% more rain days and 34% drier with 19% fewer rain days in a positive IOD. 2. There is 2% less radiation in a negative IOD and 3% more radiation in a positive IOD. 3. Average day temperature is 1.1 degrees cooler and the night temperature is 0.2 degrees warmer. A positive IOD has 1.7 degrees warmer days and 0.4 degrees cooler nights.

4. Across the sites the average number of frost days is 5 in a negative IOD and 3 in a positive IOD. Photo R Pocock

How can we manage frost?

That is beyond the scope of this short article.

However part of managing a risk is to ‘know your enemy’ and get as much information on the likelihood of that risk. What we are saying in this article is that there is a small shift in the likelihood of frost with a negative IOD and that this shift is smaller than we might first have thought given the impact of IOD on rainfall. This increases the emphasis on the sound principles of risk management including 1) understanding frost across your landscape and matching crops and landuse to different parts of the landscape.

2) knowing the optimum flowering window for winter crops and how different varieties can be used to hit this window 3) diversification in enterprises and crops including the end use of crops.

Tactics to minimise frost damage on the Eyre Peninsula Ag Innovation & Research Eyre Peninsula

GRDC investment through the National Grower Network to AIR EP has delivered a new project “Tactics to minimise frost damage on the Eyre Peninsula” for the next two years, with the aim of increasing knowledge, confidence to adopt and ability to implement the best management practices to minimise the impact of frost on farmer’s profitability.

Project partners EPAG Research have sown the main trial site at Tooligie Hill, on the border between central and lower Eyre Peninsula. This site experienced 38 below zero degrees weather events in 2021. Two trial sites have been established on a ‘high frost risk’ sandy location and a ‘medium frost risk’ clay zone of the paddock, with mirrored treatments.

Treatments include: - phenology (eg flowering at different times) - mixtures of different varieties (eg early and late maturing varieties sown together) - nutrition (eg potassium, copper, seaweed, bacterial spray) - different crop types (eg lentil, bean, safflower, linseed) - time of sowing 19 April with irrigation applied and again on 18 May - soil amelioration

The Tooligie Hill site has also had a Bednar ripped and rolled strip through the paddock which runs along the end of the trials, to see if there are measurable effects of bringing clay to the surface on the impact of frost.

Irrigation of trial plots

Demonstration sites will also be established in high frost risk areas within the boundary of Karkoo to Wharminda to Mangalo to Kimba to Warramboo, as a base for discussion group activities.

A project steering committee of local advisors plus the Farrell Flat Frost Learning Centre’s advisor Mick Faulkner, has been established to provide advice on trial and demonstration site location, questions to answer and frost management activities to test.

They will also facilitate frost discussion groups made up of local farmers impacted by frost to discuss various strategies available to mitigate frost risk and introduce them to strategies being trialled by this project.

Project code: AIP2203-001SAX

Too busy to sit down and read?

Have a listen instead..

'Better Frost Decisions' podcast out now Skip the reading and hear the highlights. MSF brings you the Better Frost Decisions podcast where we talk to researchers, advisers and farmers to learn how others are managing frost.

We chat to: Peter Hayman, SARDI Climate Applications about the climate predictions for season 2022. Will it be a wet spring and what does that mean for frost risk?

Michael Hind, is an Agricultural Consultant with Bates Ag Consulting on the Eyre Peninsula. He has been working with AIR EP and EPAG Research to help establish the new Frost Research Site at Tooligie on the EP. Jock McNeil farms at Paruna 30km South of Loxton with his dad Ian, brother Digby and sister Anna. The McNeils have been farming here since 2003 and crop 9000 ha. The farm has cropping and livestock. The cropping consists of a rotation of 60% cereals wheat and barley for 2 years followed by either vetch, lentils, peas, chickpeas and chemical fallow depending on the paddocks.

The vetch is either cut for hay or brown manure/grazing . Frost is a key issues for the farm along with low rainfall. The farm has adapted zero till, controlled traffic and weed seeker technologies, and strives to make changes for efficiency and productivity gains in a tough farming environment.

Peter Hayman

Jock McNeil

Travis Flight is the Farm Operations Manager for Tarree Pastoral at Nangari in the Eastern Mallee. Travis is part of the family farm and they have been farming here for 102 year. Travis is a Fourth Generation farmer here at Tarree. In 2016 Travis spent 12 months in Alberta Canada working on a farm, this has been invaluable in widening his experience and outlook at farming.

Tarree has an intensive piggery as part of the business, this provides a good outlet for straw and grain from the farming operation. The cropping enterprise is 5500 ha and has a rotation of wheat, barley, lupins, peas, chickpeas and brown manure vetch.

Andrew Thomas farms at Moorlands and Wynarka as a mixed farming operation with cropping, hay and livestock. Cropping a total of 3300 ha in a mixed rotation of wheat, barley, canola, lentils, beans and including hay in the mix as well as livestock to round out the farm enterprises. Andrew has been practicing zero till on the farm for 20 years and has a home modified triple disc seeder. Andrew has frost sensors on farm as part of his overall farm management program.

Travis Flight

Andrew Thomas Jamie Wilson

Precision Ag map layers to think about frost differently Upper North Farming Systems Upper North Farming Systems is thrilled to launch a new fact sheet publication, developed and written by Jessica Koch, Breezy Hill Precision Ag Services.

This frost fact sheet outlines how to use affordable and easily accessible elevation data recorded from standard ag machinery to monitor and spatially manage frost.

Coming into the 2022 growing season, it is hoped this fact sheet sparks your interest or ideas in using precision ag data in other elements of your farming operations – the opportunities truly are endless with data available at our fingertips!

Upper North Farming Systems are grateful to the Orrock family at Murraytown for providing the site for analysis and being generous with their time and sharing of data. This publication was funded by Agrifutures for the Producer Technology Uptake Project and the GRDC for the Frost Extension Project.

Click on 'Read More' to access the full fact sheet.