Transcript of the Implications of climate change on various Mallee horticultural crops webinar
Heather Field:
Okay. Hello, everyone. Welcome to today's webinar, which is on the implications of climate change on production and water requirements of various Victorian Mallee horticultural crops. My name is Heather Field. I'm a climate change service development officer with Agriculture Victoria, and will be facilitating our webinar today.
Before our presenters begin, just a few housekeeping items. This webinar is being recorded and will be made available after today. We've got everyone muted for our webinar just to stop any background noise. So, if you do have a question throughout the webinar, please pop it into the chat function, which is currently explained on your screen, and we'll make some time at the end of the presentation for questions. We do have a quick survey following the webinar and it just takes about a minute to complete, so we greatly appreciate your assistance in completing that.
So, before we commence, I'd like to acknowledge the traditional owners of the lands and water on which we are all meeting, and I pay my respects to elders past and present. I'm tuning in from Ballarat, which is the lands of the Wadawurrung people. And I'd like to acknowledge all the lands in which everyone is tuning in from today.
So, today we have the opportunity to hear more about a project looking at the implications of climate change on horticultural crops in the Victorian Mallee, and the Mallee CMA commissioned this study with Agriculture Victoria a number of years ago and we were lucky enough to hear about the first phase of the project back in late-2020. And today, we will hear a bit more about the findings of the most recent phases of the project, which are looking at the water requirements of various horticultural crops under future climate scenarios.
So, I'm very pleased to welcome our presenters today, Geoff Rix, from the Mallee CMA, who will provide a bit of an introduction and context to the project, and Jeremy Giddings from Agriculture Victoria, and Jeremy will summarise the findings of both phases of the project and how the results could be used by industry and government.
So, a bit about our presenters. Geoff is the manager of salinity and water quality at the Mallee Catchment Management Authority and is responsible for overseeing the state-funded Sustainable Irrigation Programme under Rural Water Policy and Programmes, including the oversight of the Victorian Mallee Irrigation Development Group, and is also involved in managing a wide range of other projects.
Jeremy Giddings has spent nearly 30 years delivering irrigation extension in the lower Murray-Darling. And since joining New South Wales DPI in 1996 and then later Agriculture Victoria in 2016, he has developed and delivered training in drip irrigation management, soil management, and irrigation scheduling to a range of horticultural irrigators. Jeremy is also a certified irrigation agronomist and certified irrigation designer with Irrigation Australia. Also, Jeremy has been involved in overseas citrus irrigation extension projects in Pakistan and Bhutan, and for the last three years has helped Almond Australia deliver irrigation workshops and webinars to interested almond producers in Sunraysia, Riverland, and the MIA.
So, it's great to have both Geoff and Jeremy here today to hear a bit more about this wonderful project. So, what I'm going to do, I'll hand over firstly to you, Geoff, to provide a bit of context to the project.
Goeff Rix:
Thanks, Heather. And first of all, thanks for the opportunity to allow this presentation to happen and facilitate this on behalf of the CMA and Agriculture Victoria. Thanks for the opportunity to introduce Jeremy Giddings, who we've worked closely with a number of years, as you alluded to in what we've loosely termed our climate change impacts on horticulture in the Mallee.
During the life of this project, DEECA have sponsored this climate change impacts on horticulture project. It was determined during the investigation that several phases of research and industry collaboration would be required, first of all, to identify impacts working with industries and to disseminate the findings to the industries. Particularly in phase two, Jeremy consulted with seven industry groups to discuss impacts and to share possible specific crop type impacts including phenological changes, yield, and seasonal management issues, and what steps may be done to ensure the sustainability of farmers in those various industries.
Research was done to show if no adjustments for climate change were made to production, what the impacts would be. So, that was our flat line, no changes. All seven industries showed yield decline and reduced ability to stay viable if they didn't act on the findings of climate change impacts.
The main outcome was also the need to focus on predicted water demand to maintain viability, and that led us into our phase three and specifically what Jeremy will present today, which was a research-based project focusing on the predicted change of crop water demand out to 2070 on irrigated horticulture in the Mallee. And to do so, we used two industry accepted climate change scenarios, and sorry for the technical detail here, but RPC 4.5 and RPC 8.5, and they refer to the watts of CO per square metre in the atmosphere. In layman's terms to dumb it down a bit, that means either a 4 degree or an 8.5 degree change in predicted weather in the Mallee in 2100.
Just as a side note, there's internationally accepted consensus that we've already seen a 1.5 degree change in long-term trends since industrialization in the late 17th century.
Jeremy and the CMA oversaw the development of the predicted outcomes and shared these findings with all Mallee industry groups. So, without any further introduction, I'd like to now hand over to Jeremy.
Jeremy Giddings:
Thank you, Geoff. Thank you, Heather. Thanks for joining, everybody. I guess the reason we are here probably is that I saw a presentation from the Northeast CMA a couple of years ago. They put up a number of charts, this being one of them. This shows modelled pasture growth right now on the left and predicted into the future. And obviously, the farmers on that northwestern corner might have some challenges in the future. But the point here is that this was the first time I saw a presentation made that was delivered in terms that farmers might be able to understand, that could make sense of, and meant something to them. And I thought that this might be a reasonable approach to horticulturists in the Mallee. I naively thought that it was an approach that we could do as well.
So, we started, like Heather said, in 2020, looking at assessing the impact of climate change on horticultural crops, there's seven or eight crops listed there, through similar modelling. As the project evolved, we found that the industries were more interested in determining specific production issues, and I'll present those as well. And then this was four or five years ago, we're looking at adaptation strategies that are and could be adopted by industry.
In particular, this hadn't been done before for the Mallee, we wanted to start a conversation, and the industries were highly involved and aware of this stuff and that started that conversation for them. So, early on, there was stakeholder meetings with all industries, that were required to determine the fundamental issues required for modelling. So, the phenology, the returns, irrigation and yield estimates, quite fundamental type stuff for all those industries.
What was more challenging was getting those industries to agree on rules of thumb regarding crop yield reductions. And there's a couple of examples there. Two consecutive days over 45 gives a yield penalty of 25% for Washington navel, and then there's a frost penalty below it there for almonds. All of that information for each of those industries was collected by the modeller and put together and we came up with stuff like this.
So, this is the spatial map for shiraz, a wine grape variety. We didn't get the spatial variation that the Northeast CMA found. We don't have the elevation changes that they do. We were only interested in a 250 kilometre distance, a 10K strip along the river. We were looking at irrigated crops, not rain-fed crops. And the spatial variation you do see here isn't significant. It's probably more to do with the database anomalies.
So, very quickly we moved on to point source yield declines. So, the crops that are grown in a particular area, mostly Mildura and Robinvale. And here is the average yield declines projected from the modelling for a range of crops. And for what it's worth, it's between 5, 10, 20% yield reductions in the future if nothing changes on farm. So, if farmers don't adapt either through genetics or through management. And so, that started a conversation and that's all we wanted to do.
As part of the modelling process, you need to determine the pheno stages and the length of the season and what came out of that. And we've seen this sort of stuff already, there's a predicted shortening of the season in the future. So, every crop type requires a certain number of degree days to mature a crop, develop a crop. And if we're in a warming climate, those degree days are expected to be received sooner. It's a shorter growing season, for some crops more than others.
For each of those crops, we developed a chart like this in phase two, where the dots at the top of the chart represent on average historical pheno stages. So, we're saying bud burst, bloom, nut fill, harvest, et cetera, across the top there. And then below it, depending on the emissions pathway, 4.5 and 8.5, and we've already sort of met 4.5. And over time, bud burst, for example, will be sooner and earlier and all the pheno stages following that will be sooner as well.
So, industry became interested in this. They've seen it, some more than others, like I've said, have seen it in practise. And here's a chart for citrus from a research station in the Mallee, which shows that for every year over the years it's been monitored is citrus navels are flowering, on average, 17 hours earlier than they have done previously. And since the early '90s are now flowering 18 days earlier than they were in the early '90s. So, the reality and observation is matching some of this theoretical stuff. And wine grapes have seen a similar thing. Harvest is almost earlier every year as the degree days increase and are received sooner than they were in the past.
So, I guess out of the modelling results, we've seen an estimated yield decline due to increasing heat stress and yield penalties. No real frost impacts predicted in the future. That doesn't mean that there won't be any frost impacts in the future. But we also saw a shortening of the growing season. All of that, assuming that there's no change in variety or management practises into the future. And farmers are already making those changes, and I'll touch on those in a moment.
The other thing the industries became more interested in as the project evolved was specific production issues. A couple of examples there. Chill for pistachio and an effect on table grape fruit quality. We also started to be interested in water requirements from a modelling perspective, and I'll touch on those as well. So, pistachios, out of all the crops, out of the seven crops that we're doing, are the ones that are most sensitive to chill, the most demanding for chill requirements. And so, a warming climate just doesn't mean a hotter summer, it also means a warmer winter as well. And there's a range of thresholds here, but to receive 59 units by the 31st of August each year is one of their measures. And for Robinvale, a major pistachio growing area in Victoria, that chill requirement currently is received about 85% of the time, but in the future with that warming winter, it's predicted to quickly decline. So, we presented this to the pistachio industry, they're aware of that, they were aware it before that, and they're off and running with what they need to do to address that.
Another one for table grapes, the industry said to us, "Look, we have problems with warmer weather when it's 38 degrees through the day or above, and only gets down to a minimum of 20 overnight. Depending on the time, if it's in December, it affects berry size. If it's in January, it affects fruit softening and colour development and softening after that. How many times does that occur now and what's likely to happen in the future?" And here we have those numbers and it's saying that it's likely to possibly double in the future. And they're aware of that and can deal with that as they please. So, we've got a range of those specific issues for the specific crop types, at their request, that have been produced.
At the same time, My Climate View is a website that looks pretty good, is produced with the Future Drought Fund. And they've got data here for almonds and they're saying, "Look, how many days at wet weather at harvest are going to happen now and in the future, or warm days during pollination, frost at flowering, chill accumulation?" Another one here for avocado. What are the hot days now during flowering? What are the frost days? How many cool days to induce flowering are going to occur? How many pollination events occur? So, that's a pretty good, useful website. You can google, it's called My Climate View. It's got a range of crop types in there, not just horticultural crops, there's broadacre crops, there's some animal industries in there that talk about cold events, cold exposure at lambing, that kind of thing for lamb production. So, have a look at that. That goes into more detail than probably what we did, and is a pretty useful website for a range of industries. And those industries are increasing in that website all the time. Additional industries are being added to that website all the time.
Adaptation strategies. And we've seen this quite a bit, developers are looking at alternative varieties, varieties that come from hot climates to begin with. Italian and Spanish wine grape varieties, citrus variety from Pakistan, Kinnow, which produces its fruit within the canopy. It's shielded from the heat. It's adapted to that hotter climate. It's come from that hotter climate. That kind of thing is happening more and more.
You talk about breeding. Whenever you see a new variety, whether it's a rootstock or a scion being released, often they talk about its drought tolerance, its heat tolerance. That sort of thing is becoming more of interest and importance to horticulturists.
Canopy management. We're seeing this already. We used to be interested in wine grapes, for example, and more exposed fruit. Now we're producing canopies that larger, that shield the fruit either through pruning or irrigation or trellising and avoid that direct exposure.
And we see cooling methods such as these, the netting on the left becoming more and more common for high-value crops, and the above canopy misting on the right-hand side, again, for high-value crops with triggers for certain temperatures that are reached and to create misting. Particularly high-value crops that are sensitive like table grapes, avocados, mangoes, some citrus varieties. So, that's what's happening now. That's already happening. It's been happening for some time and you'd expect it to maybe increase as well in response to heat events and what you might call climate change.
I mentioned we started to look at crop water requirements in that phase two project. If you think that the climate's going to get warmer and drier, there'd be an increase in evapotranspiration, which drives our crop water requirements. And from a modelling perspective, given that I said earlier that the season was modelled and expected to get shorter, well if you put water requirement modelling on top of that, we found that there wasn't a real increase in water requirements from a modelling perspective. And for some crop types, the model said that water requirements will reduce, purely based on that shortening of the season. And that didn't really hit home and gel with us. So, as Geoff mentioned earlier, phase three of the project, the most recent one last year, it finished up looking wholly at estimating crop water requirements.
The equation on the screen is the conventional method of measuring crop water requirements or irrigation requirements. Three numbers here in the brackets, ETO is the number we get from the weather stations, the Bureau of Met, evapotranspiration. You multiply that by a crop coefficient, a specific set of numbers, the Kcs are a specific set of numbers that relate to the canopy development for every different crop type. So, almonds have a specific set of crop coefficient numbers, wine grapes have got different number. And then, effective rainfall. So, this first multiplication determines your crop water requirement, and then if there's any rainfall there, you take that away and maybe divide it by a constant here of 0.85, which represents the fact that we're irrigating at 85% efficiency.
Are predictions of those three numbers available into the future in order to estimate future crop water requirements? And it so happens they do. Evapotranspiration projections are available through the Australian Water Outlook, through the BoM. Soil crop equation's used, and the dotted line here represents the historic ETO values, and the numbers depending on the time and the emission pathway are above those solid lines. And they represent an increase of between 2 and 10% over time. It's due to an increase in vapour pressure deficit, which is driven by higher temperatures. Higher temperatures drive a higher ETO.
Kc values. We've got long-standing, recognised crop coefficient values for all crop types. This is almonds again. The dotted line represents the historical Kc value. So, we're talking about a deciduous crop in this case. Buds burst, canopies develop over spring and summer. So, that's why that number is increasing. Then it flattens out over summer and then declines as leaves drop off and senesce. The dotted line is the existing one. I mentioned earlier, if we see bud burst happening earlier, we'll have a canopy developed earlier. And so, the future lines have all moved to the left to recognise that change in the way the canopy and the crop is produced.
We've done that for all seven crop types. Six of those are deciduous. We've got citrus in here which are wintergreen, evergreen, and their crop coefficient stays the same. What we've got, if we look at almonds again in the top left-hand corner, we've got that season starting earlier, but it doesn't necessarily finish any earlier. And we've discussed this at length, researchers from Queensland in particular. The end of the irrigation season is recognised by leaf fall and leaf fall generally occurs by cooling temperatures and frosts, et cetera, knock those leaves off. We're saying that leaf fall stays the same as it always has and the start of the season starts early. So, we haven't necessarily got a shorter season in effect. We've got a slightly longer season predicted into the future, combined with a slightly warmer climate with higher evapotranspiration.
Effective rainfall. For the Mallee, we don't have a lot of rainfall, let alone effectiveness. The dotted lines again represent historical effective rainfall and the solid lines below it represent the reduction in effective rainfall over time depending on the emissions pathway. And we are looking at reductions particularly in spring. I think 31% on average and probably 25% overall. But again, look at the numbers on the left-hand side there. We're not talking about a lot of data there, but it goes in the equation.
So, it ends up we have got future predictions for those three numbers. We've got the ETO from the Australian Water Outlook, we've got Kc values that are adjusted for the new pheno stages or the altered pheno stages. We've got effective rainfall, for what it's worth. When you crunch all those, we get an increasing water requirement. For the low emissions pathway, which we've virtually already met, of between 3 and 7% over time. And for the higher emissions, it's 5 to 13% increase in the long term.
It doesn't sound like a lot. If we look at the individual crops from left to right, I mean, we pick on almonds again. RCP 8.5 is greater than 4.5 across the board. The projected water requirements in 2070, which are in yellow, are higher than 2050, which again are higher than 2030, and are higher again above the historical, which is in blue. But on average, sort of 100 to 150 millimetres of extra irrigation requirement. Again, doesn't sound like a lot. It's a meg to a meg and a half a hectare. It is a significant amount of water if you consider the level of development that has occurred. And also, the danger in just looking at an average, and this is probably where we might look at this sort of thing in a phase four, is look at the extremes. We're looking at an average here, an average of a meg, a meg and a half. But what about the extremes? That might be more frequent as well. So, there's that data.
So, I guess to finish off, the key messages are, I've got up there a shorter growing season expected. I would call it an altered growing season, and it might be a shade longer, as I've shown earlier. Without adaptation, yield decline will most likely occur due to heat impact. We see that in the media, heat events have caused this crop to collapse, et cetera, et cetera. A range of possible production issues have been developed for each industry, both ourselves and that website that I mentioned earlier, through the Future Drought Fund. Growers are already adapting to climate change through altered management and have been doing so. It's a gradual thing. They're talking about high-value crops there, that they want to be protected.
And the water requirements that I just mentioned earlier, 3 to 7% for low emissions, and 5 to 15. And we predicted that Australia is going to be operating around RCP 6. There's no data yet for RCP 6 specifically. So, we're somewhere in the middle of all the data and the ranges that I've presented so far.
And Heather, that's about it from me. I guess we should acknowledge, we've mentioned the CMA, the consultants involved, Natural Decisions with Anna Roberts. Phase one and two were RMCG, primarily Charles Thompson and Natasha Frazer, and Ag Vic. Craig Beverley, the modeller, did a great deal of work for phase one and two, and got the conversation started. But Heather, I don't know, we've got to half past 12, and I'm done.
Heather Field:
Yes. Yeah, no, all great.
Jeremy Giddings:
But that's-
Heather Field:
Yeah, fantastic. Thank you, Jeremy and Geoff, for the introduction. Really great to see a project that's definitely looking at what the future climate predictions are looking like and how people may be able to adapt, whether that's alternative varieties or breeding or various management.
So, just as we wait for ... We have got some questions coming in, which is great. I have popped a couple of links into the chat. So, a link to My Climate View that Jeremy referred to. So, you've got that there if you want to have a bit of a look at that and the different varieties and other crops on that website. And also, a link off to some fact sheets and the phase three report.
So, I might just start with the first question and then I'll have a bit of a further look through with the questions coming in. And we have got about 90 people online, so good amount of time here for questions through till one o'clock. So, the first one is, "We've got greater extremes from the average in weather, maybe experienced by climate change. Can our existing infrastructure cope with these predicted changes?" So, throw it open to either of you two to respond for that one.
Jeremy Giddings:
Yeah. That might be a subject to look at further. Because we looked at averages, that was part of the charter for phase three. It's saying that existing irrigation infrastructure might be set up to deliver water, 10 ml a day. What happens if we start hitting 11 or 12 more frequently? How do we keep up? What do we do about that? And I guess that's something we need to look at, especially if we start looking at extremes.
From an average point of view, those numbers didn't change a heck of a lot. I mentioned that from an annual application, it only increases 100 to 150 millimetres. If you drill that down to a daily average, it's insignificant, it doesn't look like anything. But if you combine it with the extremes, then it's probably worth starting to look at. And so, that's on farm irrigation systems as well as delivery systems from state organisations through channels and pipelines that deliver to hundreds of farms, whether those systems are designed to keep up, it's probably something worth looking at it.
I think the greater increase in demand has occurred with the change over to alternative crops that require higher demands. The crops that are doing well have a higher daily average than those that we used to grow in the past. Almonds and table grapes have a higher average demand, that's probably raised the ... And created more strain on the system than climate change has done so far.
Heather Field:
Thanks, Jeremy. We've got a question from David about, "Did you multiply GCMs for each future scenario?"
Jeremy Giddings:
GCMs?
Heather Field:
Yes.
Jeremy Giddings:
Which are what?
Heather Field:
Sorry?
Jeremy Giddings:
What's that stand for?
Heather Field:
Oh, what does GCM stand for? Well-
Jeremy Giddings:
That might be another question.
Heather Field:
That might be a question back to David. So, if you want to pop that one in the chat, just to clarify your question. I might just have a look. Global climate models, of course it is.
Jeremy Giddings:
And the question?
Heather Field:
"Did you use multiple global climate models for each future scenario?"
Jeremy Giddings:
That'd be a question for the modeller. I'd take that to him.
Heather Field:
Take that one on notice?
Jeremy Giddings:
I left that with the modeller. I think it was ... No, I couldn't answer.
Heather Field:
No. All good.
Jeremy Giddings:
[inaudible 00:34:09].
Heather Field:
We'll get back to that one. Question around, "Have you shared this project and the findings with other water authorities such as Lower Murray Water?"
Jeremy Giddings:
DEECA have been interested with releases and looking at the future water requirements, I guess, and we've delivered it to every industry. I don't think it's specifically to the water authorities. I think it'll become more relevant to them, as I discussed in that first question, once we start to look at the extremes and how that might affect their delivery. But we've got a great relationship with them, and they're not far away. And that'll happen when it needs to.
Goeff Rix:
Yeah. And to add, I believe the water authorities have for quite a period now been looking at sustainability of their systems as climate change unfolds. And this will also feed into that. The point Jeremy just made then more is on the extremes. While we've done the research on the average, we really want to understand how often is a standard of deviation going to occur from that average? Are we going to see a week of 45-plus degrees Celsius in the Mallee and will the infrastructure be able to cope with that? And we don't know the answers to that yet. Obviously, through investment over time on infrastructure it will, but to make that the right investment, that's where some more research needs to be done.
Heather Field:
Thanks, Geoff. And that might flow into a bit of our next question, which is, there's been some really great results come out of these the last three phases and whether you've got a bit of a comment on what types of issues or questions would you like to explore should you have a future phase or a next phase?
Goeff Rix:
I think Jeremy just pointed at me, and I've just alluded to it then, obviously water is the big question. Cultural practises and development of different varieties to cope with climate change and it can be done over time and the industries are proactive in developing that. And as I alluded to, cultural changes like, and Jeremy showed pictures of it, misting and cooling mechanisms and other techniques to minimise or reduce the climate change impacts can all be adopted if the viability of the crop warrants that, and that is sort of, who knows what table grapes and almonds are going to be worth in the future. They're the unknowns.
But what we really want to know is from a water availability and water demand standpoint, can we meet those extremes? How often are those extremes going to occur? And what investment would private and public infrastructure need to make to meet those future demands? It's not easy to map that out, as the further you go, the expanse or the width of what you'd need to cover extrapolates. So, obviously by 2070, how much water is the Mallee going to require to stay viable? That's still variable. We know without a doubt it's going to increase. We just don't don't know how much at this stage. But yeah, research like this will help give us confidence in those predictions.
Jeremy Giddings:
And some other areas we're going to possibly look at, Geoff, with phase four?
Goeff Rix:
We've thought about, and Jeremy touched on it, infrastructure ability to cope. We've thought about where there's horticulture with no shallow drainage systems, we work on a leaching factor or there's industry accepted practise that not all the water you apply is going to be used by the crop and there's certain amount of that water will leach below the root zone and will either be collected in drainage systems or not collected in drainage systems if there's no drainage there. And there are thousands of hectares in the Mallee that are irrigated where there's no shallow drainage system.
So, if we predict that there's going to be more water applied, that in theory means that there will be more volume of water leached below the root zones. And what will be the impact of that in undrained systems firstly, because in the traditional growing areas and the pumps district, there are drains, and over efficiencies for the last 20 years, the amount of water in those drainage systems has decreased. So, a gut feel is that those systems will be able to cope with an increased volume in drainage systems. The real issue is what about undrained development and what will be the impact? Will there be more water logging? Will a developer need to invest in drainage systems in their high risk areas to cope with that increase in application? That's another area that we would really like to investigate, to get that message out and to let growers think about that.
Yeah, I think that's about it. Availability, drainage, system capacity, and analysis on the extreme predicted weather changes.
Jeremy Giddings:
But we're open to suggestions.
Heather Field:
Excellent.
Jeremy Giddings:
[inaudible 00:40:27].
Heather Field:
No, look, there's plenty to do for another phase or two or three more by the sounds of it. Thanks for that. We've probably got another question, but it might be again, a little bit on the modelling, I'll mention it. But we have had someone, Dougal did mention that Craig Beverly's work was using the Access, I think it's SSS, or Access 1.0 model. So, if we can't answer any of our modelling questions, we'll definitely pose those to Craig and get an answer.
But there was one from James from New South Wales DPI, who's interested in the thermal time modelling for horticultural crops. So, is interested in doing this in a project that they're doing, but looking for pre-existing phenology models for horticultural crops. So, was keen to know, are you able to describe how you did this modelling as it doesn't appear in one of the linked reports? So, is that a question for Craig that we can take on notice or can you comment?
Jeremy Giddings:
No. No. Maybe Dougal might, or if Craig's listening, but yeah, that's another one for them as well.
Heather Field:
All right.
Jeremy Giddings:
And we've had a little bit to do with all other agencies because we all want the same thing, and the origin of the data, we want to be fundamental. And whichever direction the research takes might be different, but the fundamental stuff, we want to be consistent. That would make sense.
Heather Field:
Yeah. Thanks, Jeremy. Now, I've posted phase three report. Is there a phase one and two report online at all that we can post too, Geoff?
Goeff Rix:
Definitely a phase two report can be made available as well. I can supply that, Heather.
Heather Field:
Excellent. That'll be great. What I'll do, I'll pop that in our recording and everyone who's online today will receive that, so will have access to that report. Question from Sarah, "Did your research uncover any opportunities from climate change?" So, in a positive sense.
Jeremy Giddings:
Well, look, the frost impact makes sense in hindsight, but yeah, that's an opportunity. I know the northeast one, those charts that I showed earlier, showed that there's some winners and losers with climate change. I think canola in theory may have been more favoured in climate change, maybe related to less frost as well. But from our point of view in the Mallee, only with regard to frost across the board in the general sense was a favour that comes to mind. That's the only one that comes to mind.
Heather Field:
Yeah. No. Thank you. And carrying on from that, did you assess impacts attributed to increased frequency and intensity of extreme weather events such as storms, hail, wind, flooding, that sort of thing?
Jeremy Giddings:
Yeah. In the individual commodity indices, if they had said, and many of them said, what's rain going to be like at harvest or some other critical growth stage? And so, that's in that phase two report. And it's also mentioned in the Future Drought Fund one that Heather's put up there, the My Climate View. Critical stages, if certain things happen, whether it's rain or heat, most likely, at flowering or pollination, et cetera, they're starting to be documented.
Heather Field:
Thanks, Jeremy. Whoops, we're jumping around. The results that you've shown today are influenced by changes in phenology. How confident are you of the modelled phenology in the historic period and how confident are you that the phenology models will be relevant in future climates?
Jeremy Giddings:
Yeah. Well, you know they're not going to be right, and that's the nature of modelling. And the challenge is, and you saw those charts with the dots, we have to put a specific date to allow the modelling to occur, a specific date for each of those stages. And you know that doesn't occur in reality. It occurs over days and weeks and it varies depending on the season, but it is a starting point and we've got to start somewhere. Yeah. And that's all I could say, that it's an attempt at this, and hopefully it creates some interest and there's some more attempts at this.
Heather Field:
Yeah. It's getting that conversation started, isn't it?
Jeremy Giddings:
Yeah.
Heather Field:
Which leads into the next question, which is, "What's your sense of industry response to these projected impacts and how they currently engage with or access climate risk information like this?" And you've mentioned the My Climate View as one way.
Jeremy Giddings:
Depending on the industry and how impactful it looks, they've responded ... I mean, I mentioned pistachio, and we've done presentations with them, and they've always have been and will be interested in the challenge around chill and what it means. And now they've got some fundamental data.
I remember in the almond workshops, the almond breeder from Adelaide Uni was interested in this and said, "Well, if that's going to be the case in the future," and I'm paraphrasing here, "if that's going to be the case in the future, well I've got some selections that'll do this and this maybe." So, there's that sort of angle. But yeah, it's a conversation starter, and they're probably the two that come to mind where industry has to some degree shown a bit more interest than normal, but there's an awareness thing now and away they go.
Heather Field:
Yeah. Yeah. Terrific. So, in your discussions, were there any potential pest or disease implications from the future changes that could come into play?
Jeremy Giddings:
No, only implied, given winter warming and stuff like that, and overwintering of pest and disease. But no, we didn't touch on that, and that might be a phase four issue. Thank you. No, it wasn't directly touched on.
Heather Field:
Yes, we've had a couple of people ask the same question. So yeah, definitely might be one to think about for the next phase. And also added to that, effects of crop spraying in a warmer climate potentially as well, could be one to consider.
Jeremy Giddings:
Absolutely. I think one of the things for pollinators, maybe almonds, we looked at temperatures during pollination because the almond industry were concerned about that, there might be an extreme or a threshold that they were concerned about. So, that's been documented as well. That would be the closest we came to pest and disease, although it's not a pest or disease, it's an insect. [inaudible 00:48:30].
Heather Field:
Yeah. We've got another one from Dougal, which you might need to take on notice as well, but I'll read it. It's a kind of question/comment. "In reality, the difficulty in getting the yield and phenology information to calibrate and validate, improve the models, this information was provided by growers which allow the iterative process of getting the model to match expectations for phenology stages, yield, and quality." So, a bit in that. Not sure if you can comment or one that we can take on notice.
Jeremy Giddings:
No. No, that's a statement and a good one.
Heather Field:
Yes.
Goeff Rix:
And the industries themselves keep a lot of data on yield and seasonal data as well as long-term data. And that will also improve the confidence on the changes over time and the predicted changes in the future.
Heather Field:
Thanks, Geoff. I'm just scrolling back up through some questions that we may have jumped over. There was one about, "Have you calculated the increased demand across the whole system?"
Jeremy Giddings:
Yeah. I think we've got very good data on crop statistics and that's an easy one to do as part of phase four, for sure. Yeah.
Goeff Rix:
Probably at a really high level. The take-home messages I see regarding water use and I'm only focusing on predicted water use, between 8 and 13% by 2070. How is the Mallee going to come to realisation and be able to cope with that? There's a number of things, but that's the really high message I look at, increased water demand.
Heather Field:
Thanks, Geoff. I have got one here that I've jumped over, which is, "You have the irrigation efficiency of 85%. Is this under tree sprinkler? And by the last prediction chart, which you showed water use for citrus is currently 12 megs. This seems high. Have you done anything with drip?"
Jeremy Giddings:
Yeah. Yeah. Well, citrus we see a significant difference moreso than many other crops between drip and full cover sprinkler. But the trend and the percentage increase would be the same. But yeah, that 12 is probably a little high, but you'd be more interested in the direction that it's going.
And I guess, we've been thinking about this, 85% has been ... So, that's saying a 15% leaching fraction, and Geoff talked about a 10%. And I think as things get warmer and drier and water gets more valuable, then that 5% starts to be looked at more realistically through necessity or design. But yeah, 15% is probably closer to full cover sprinkler. And then certainly, there's irrigators out there that are operating at 5 or 2, if you can measure that precisely, 2%. There's some good irrigators out there, and especially rare. Water quality at the moment's quite good, there's not a lot of salt in the Murray, that leaching isn't necessary, strictly speaking.
Heather Field:
Thanks, Jeremy. I got a comment and that was just from Peter, he needed to leave a bit early, but, "The '24/'25 for stone fruit at Swan Hill seems exactly what is predicted here. Early and short growing seasons, which impacted size in a big way, but a continued long season requiring more and extended watering and water requirements."
Jeremy Giddings:
Is that from My Climate View or his observation?
Heather Field:
Observation, I believe. Yeah.
Jeremy Giddings:
Yeah. So, I guess, when we're talking about stone fruit and pistachios are another one, the crops that are closer to the threshold with regard to winter chill and a warming climate, their bud burst, those deciduous crops mightn't be earlier like we've shown, but the others that aren't anywhere near being in trouble with winter chill, yeah, their bud burst might be earlier. The other ones might be interrupted. Stone fruit, apples, pistachio, that's something we need to look at in more detail.
Heather Field:
Okay. I think we're nearly at the end. We have got a couple that might be more for taking on notice about similar work being done for increased water use for livestock with increasing temperatures. So, there was a bit of work done in the Northeast, I believe, that Craig Beverley was involved with, which was similar to this project. That's right, isn't it, Jeremy?
Jeremy Giddings:
Yeah. Yeah. I can't recall whether the livestock, but there's certainly pork and lambs and maybe others in that My Climate View website. Which is a good start.
Heather Field:
Yeah. And on our climate webinar webpage, which you'll have a link to when you get the recording, we've got some backdated climate webinar recordings, one from the first phase of this project, but also some of the work that was done in the northeast. So, well worth having a look through that to get a bit more information.
And I think the last one is just a possible inclusion for phase four and the fact demand will increase and supply would not likely increase, then research which crops will drop off in the region.
Jeremy Giddings:
Yeah. Yeah, it's an economic analysis certainly worth thinking about, for sure.
Heather Field:
Excellent. No, thank you for those ideas. They've been really good to hear from. So, I think I've gone through all the questions. And I will take a few on notice there in the modelling and see if we can touch base with Craig Beverley and get some responses to those ones following today.
Okay. So, I think we've come to the end of our questions. Great session, great little panel discussion there. Anything else either of you would like to add before we close out?
Goeff Rix:
Just that I think we do need to continue this research and it is very valuable. And the industry groups, as Jeremy alluded to, are taking this research seriously. So, it is important.
Jeremy Giddings:
And for me, I guess, when I said earlier it might've been a bit harsh to say that the data will be wrong. I mean it will be, that's the nature of modelling, but it's the trend and the direction that should create some interest and the conversation start as well.
Heather Field:
Yep. Absolutely. And yeah, we've got a few thanks coming in and just great work, great project, and good example of looking into the adaptation side of things. So, very much appreciate that and keen to hear about the next phase and some of the outcomes of that one.
So, we might pull it up there. And I just want to thank everyone for your participation today. Some great questions coming in. And thank both of our presenters, Jeremy and Geoff, for their time today and sharing the project and this third phase of the project. All those links that we have included will be in the recording that will be sent out over the next few days. And there will be that short survey when you close out. So, please just give that a minute and provide any feedback there, or even any other questions or ideas you might have for future phases as well. So, I will leave it there. And thank you all for joining us today. Thanks, everyone. Thanks, Geoff. Thanks, Jeremy.
Jeremy Giddings:
Thanks, Heather.
Goeff Rix:
Bye-bye.