Transcript of the farm weather stations and what they can do webinar

Alice Ritche:

Our webinar today in our Climate Webinar series is on Farm Weather Stations and what they can do.

Alice Ritche:

Today in this webinar, Leighton will explore all things weather station, so how to collect and interpret weather data, how to monitor fire danger, what to consider with soil probes, and measuring and managing inversions.

Alice Ritche:

Leighton will outline some of the examples he has installed and how they're being used to provide value for farmers. Leighton Wilksch is an ag technologist based on the Yorke Peninsula, who provides weather, soil, moisture and crop monitoring hardware and solutions, backed up with agronomic service across South Australia and Victoria.

Alice Ritche:

He has over 20 years' experience in the dryland broadacre market, being a research agronomist for Landmark and then starting his business Agbyte in 2009. Agbyte provides innovative solutions for decision making based around weather, that enable users to intuitively decipher data to assist them with farm management.

Alice Ritche:

Leighton also has a long history of being involved in farming systems groups and is the current chairperson of the Ag Excellence Alliance, which is the overarching body for all SA groups.

Alice Ritche:

Over to you, Leighton.

Leighton Wilksch:

Thank you very much. I'm hoping we've got some volume there, you can hear me?

Alice Ritche:

Yeah, all good.

Leighton Wilksch:

Thanks for the opportunity to present and thank you, Alice, specifically for following me up, chasing me up to put this together.

Leighton Wilksch:

I'm going to go through a PowerPoint presentation today, just with a range of different slides, to try and outline what I do, and where users, which for me is primarily dryland broadacre farmers, where they can get the most value out of weather and soil moisture data.

Leighton Wilksch:

I have been putting out weather stations and soil moisture sites for about 10 years now and learned a lot of things along the way. Certainly didn't get it right at the beginning, or everything right in the beginning, so learned a lot from my mistakes. Also, I have been on this journey at the same time that Smartphone adoption all across the world, but also in the ag industry has been quite prevalent, changing the way displays are used as needed to suit the way that clients are using phones to help make management decisions.

Leighton Wilksch:

I'll get into it now, just to outline what I do, here is just a range of weather stations sites that I've put in. There's a photo there with the canola field in the background. That's showing, two weather the stations, one system mounted on the fence post, which is quite typical of the sites I put out. Wind speed, wind direction, temp, humidity screen there, rain gauge.

Leighton Wilksch:

The rectangular box, you can see it's sort of slap bang in the middle of the weather station, that's the telemetry. That's the clever part that logs all the information. The sensors plug into that. It's got a battery in there and that connects to the Telstra network in this situation and pushes the data through on a regular basis.

Leighton Wilksch:

We also make portable mobile weather stations. That's the one you can see at the front, on the weeds, they're trampled down there. The field monitor, that one is used in hay baling situations, so it has the leaf wetness sensor, and the temp humidity, and rain gauge on it as well, so that could be quite easily moved around on the back of the ute.

Leighton Wilksch:

I'll talk a little bit more about temperature inversions in a little while, but the site you see on the right-hand side of that picture there, that's got a 10 metre tower. Up on top of that 10 metre tower is a temp humidity sensor. It is also the weather station mounted on the fence there that you can see. So this used for general weather information, but also looking at the temperature inversion information, spraying applications.

Leighton Wilksch:

When it comes to selecting where the stations are, there's a whole range of options out there. I do say to customers you pretty well get exactly what you pay for. If you are in the market for something around the home that connects to a Wi-Fi network, then there's quite a lot of suitable weather stations for three to $500 that'll do the job, connecting to your Wi-Fi network in your house or your sheds. But if you want something more robust that's going to last a long time out in the field, then you certainly need to be thinking about paying more money than that.

Leighton Wilksch:

Having the modular and scalable allows for, I guess, the basic unit to be put in, and that might be just measuring rain gauge and a soil moisture probe. Down the track, other additional sensors can be added in, pretty handy, just as income comes in over the course of a few years and things can be upgraded, and scaled up. I find that quite useful to do it that way.

Leighton Wilksch:

Also, the ability to actually custom build. I've got a number of sites with research farms, so they're looking at solar radiation, in addition to other weather sensors, just to help with things like a evapotranspiration calculation.

Leighton Wilksch:

Whilst it often gets overlooked, because there are other things on the farm that need to be maintained, such as tractors and harvesters, they do need to have a little bit of maintenance in and that should be easy as well.

Leighton Wilksch:

The biggest issue I have with weather stations sensors is the rain gauge. Rain gauges never really measure enough rain, but often black spiders or stubble or something has gotten caught in the catcher. So the ability to, I guess, diagnose over the phone what an issue might be, and for the site owner to get out there and do some maintenance, is quite handy to be able to do. Mounting on a fence line, so that they can be accessed or a roadway is also pretty handy.

Leighton Wilksch:

I've just got a picture up here, a Google Earth picture, of station and some monitoring sites I have, so I do traverse into Victoria. I'm based where that red star is on Yorke Peninsula, an hour and a half north west of Adelaide. I drive all over the countryside with the monitoring sites in. Actually, just out of interest, come from a family farm, not that I'm involved in the farming business, but that's over on Eyre Peninsula down near Port Lincoln.

Leighton Wilksch:

As you can see, I've got quite a few sites on the Yorke Peninsula and through the mid-north here in South Australia, but also some other clusters around certain areas.

Leighton Wilksch:

Just giving a bit of an indication about weather data and what to expect with displays. There are a whole range of ways of displaying the information. It almost seems like every week there's a new display for farm information that quite often has a weather component in there.

Leighton Wilksch:

It's certainly something I'm working on is providing a more intuitive display of information and more user friendly. I'm primarily using Adcon telemetry and Adcon software to display what I do. It is a bit 2007 or '8. It needs a bit of a review and that's happening at the moment.

Leighton Wilksch:

Essentially, information needs to be displayed in a clear, usable manner and also to have a timestamp. It is a little bit blurring in this picture here, but on this circulating, or certainly going a circular around where the timestamp is, so that was actually information that was taken this morning from one of my local weather stations here. There is the current information there, temp, relative humidity, wind speed and wind direction.

Leighton Wilksch:

Then we also have extension calculations of weather data that's done on the software. It's not done at the weather station site. It's done on the software before it gets to the display. Those extensions are things like Delta T, and Fire Danger Index and dewpoint. That's where the software needs to take actual observations and put them through some form of calculation and then spit out an answer or another value.

Leighton Wilksch:

When it comes to the display of where the stations connect to a network, and in most cases Australian weather stations, that is a Telstra 3 or 4G network. It could also be Optus, but with our coverage, Telstra is primarily where it's at. The connection interval is something where the telemetry unit connects and pushes the data through, often that's set at 15 minutes, more regular might be 10 minutes. And more remote sites, it might be through satellite connections, say it might drop back to say, an hour through connection interval.

Leighton Wilksch:

There's also something else to consider, which is the sensor read time. Weather stations will have varying parameters for how long that should read a sensor to take an average of wind speed, for example. Some sites have sensor that are permanently powered all the time and so it just takes an average at the end of a cycle, if it's a 15-minute cycle.

Leighton Wilksch:

As I mentioned there, the extension calculation timeframe, sometimes when servers get loaded up with calculations that might be running hundreds or thousands of these calculations, depending on the weather stations, every 15 minutes. Of course that can load up a computer or a server, so ensuring that those calculations run in a suitable time frame is important.

Leighton Wilksch:

It needs to be, I guess, considered with a weather station, that there are lots of steps in the process, to get the sensor, or the information read at the weather station site for it to be pushed over the Telstra network or a network, for it to go to the software, for it to have the extension calculations happen, and for it then to go to the display. If one of those steps goes wrong, then you can sometimes end up with information that's not current.

Leighton Wilksch:

I'm just going to delve a bit deeper now into some of the extension calculations which I've found clients are using to help them make management decisions. Frost severity is the first one I've put up here. This is, the way I am displaying it, is utilizing cumulative hours of frost severity. The graph that's showing there is from the 24th of August 2019, or the week starting the 24th of August, and it was a week that was particularly frosty across a lot of southeastern Australia and it caused damage to crops.

Leighton Wilksch:

A couple of points there. Temp humidity sensors are typically mounted at 1.25 meters off of the ground. That's kind of our standard height from the world meteorological organisation. That's where I've mounted all of my temp/humidity sensors at that height.

Leighton Wilksch:

When it is 2.2 degrees Celsius at 1.25, typically it is zero degrees at ground level. The figure of 2.2 degrees is important, at 1.25, as it's a way of kind of your threshold for how cold it is at ground level, zero degrees there.

Leighton Wilksch:

When I display the frost severity index, I'm essentially adding up the minutes below 2.2 degrees and I add that up and display that at 9:00 AM each morning. The graph, you can actually see there, the black line is showing the daily max and min temperature. The blue line is actually the dewpoint which can also have an impact on frost severity, which I'm not going to go into now. And then we've got a scale green, yellow and red. The red band there is below zero degrees. The yellow band is below 2.2 to zero degrees.

Leighton Wilksch:

What I've got is two arrows on the right-hand side there, and those two arrows are showing where the black line of temperature is crossing that 2.2 degree threshold. Then right down the bottom are solid blue columns, dark blue columns. The ones with the star in the middle of it, that is showing that there were approximately 500 minutes of below 2.2 degrees the day thereof, the 30th of last year.

Leighton Wilksch:

That's just trying to give a good intuitive way for a user to look at 9:00 AM each morning to see, okay, there's a big block there. There's lot of minutes there. I know I've got a problem and I need to get out, need to start thinking about what I might go and do about that. As I said, that was a particularly horrific week that week, where there were multiple days of frosty conditions.

Leighton Wilksch:

Moving along now to temperature inversion monitoring, just on the right-hand side there, I've got a photo. This is on the family farm at Karkoo on Eyre Peninsula. Again, that's just an old UHF tower that was surplus to requirements, that they've concreted in the ground. I've put a temp humidity sensor up the top of that 10-metre tower. By my ute, you can see the weather station there with the temp humidity screen, sitting at 1.25 meters above the ground.

Leighton Wilksch:

Essentially, temperature inversion monitoring is looking at the difference between the 10 metre and the 1.25 metre sensors. Temperature inversion is a subject that GRDC and other organisations have done a very good job over the last four or five years of just making grain producers and cotton producers aware of the impacts of temperature inversions on spray application. Any mornings we get a temperature inversion where it is warmer at 10 meters or above the surface, than what it is at the surface, there's a whole range of weather conditions that lead to temperature inversions.

Leighton Wilksch:

By having a weather station with an inversion tower, we are able to quantify what we feel, or see or observe with a temperature inversion. Temperature inversions often show themselves as layers of fog when driving at night that you might see with your car. Or during summertime during harvest, we often see calm evenings where the dust from a harvester or a truck driving down the road just hits a layer and that might be five or 10 metres above the ground. It starts to drift sideways. It doesn't move through the air, or go upwards through the air.

Leighton Wilksch:

There those inversions impacts, I guess, that we see and observe. By having a weather station, we can actually quantify and put some numbers around that and therefore use that information to actually make a decision.

Leighton Wilksch:

I've got a graph there that is showing information from the week starting the 1st of May, so that's this week. Of a site near, we're I live on the Yorke Peninsula. The top panel of the graph is showing a brown and a red line. The brown line is the 10 metre temperature, the red line is the 1.25 metre temperature. Then down the bottom of the panel of the graph is the blue line that's showing the difference between the 10 and the two.

Leighton Wilksch:

Circled in red are two days at the start of this week where there was very little difference between the 10 and the 1.2 metre temp sensors. So there really was no inversion conditions present there. I've got a blue arrow that shows, that's on the 3rd of May. That blue arrow is pointing where there's a sharp dip downwards, where the temperature at 10 metres would have stayed the same, but the temperature at 1.2 metres dropped away. So there was quite a rapid inversion formed there and then that inversion went away.

Leighton Wilksch:

We move to where the green arrow is. That was actually last night. We had a bit of wind here in the afternoon. That dropped away and we had inversion conditions rapidly form. That green arrow is showing where essentially the blue line drops right off and we have had warmer conditions at 10 meters than what we did at 1.25.

Leighton Wilksch:

That's just the way I'm displaying temperature inversion information. In South Australia here, we've been very fortunate with funding from PIRSA. That's the Primary Industries and Regions of South Australia have funded some very high quality expensive weather stations through the mid north of South Australia.

Leighton Wilksch:

This has been driven by issues we're seeing in the Clare and Barossa Valleys where phenoxy herbicides, particularly, have been sprayed when there has been inversion conditions present. Those phenoxy herbicides can move significant distances, potentially 50 to 100 kilometres, in the right conditions, or the wrong conditions, I should say. Ending up in vines and people's gardens and on their rooftops and causing issues of off target drift.

Leighton Wilksch:

The South Australian government, through PIRSA have funded these weather stations to monitor inversion conditions through the mid-north. That information is then displayed for grain producers and the general public to use for decision making.

Leighton Wilksch:

I just took a screenshot of the conditions, earlier this morning showing a vertical temperature difference. As you can see, the information is displayed in a stoplight design, so red indicating that there's a larger inversion condition. The orange saying there is zero to little. The green saying there essentially is no inversion conditions there.

Leighton Wilksch:

That's not necessarily saying yes, you can spray or no, you can't spray. But it's a step in that direction, just showing where conditions are, I guess favorable and unfavorable.

Leighton Wilksch:

There's certainly been a great adoption of using a SA Mesonet through the Mid North, since it was commissioned last year. Lots of people are using the data. And as we learn more about the inversion conditions, I guess, there'll be more information out about how to use the information.

Leighton Wilksch:

Just recently, PIRSA have announced funding for another Mesonet inversion monitoring weather station networked to go through the Riverland and Murray Plains. I've just circled that in the blue there. There'll be another 16 sites, I believe, go up through that area in there.

Leighton Wilksch:

For those of you listening in from Victoria, that's probably a good network to get a bit of a feel for and to potentially pressure those government to set up similar kind of networks, because it has shown to be a fantastic tool for managing spray drift.

Leighton Wilksch:

Moving on now to Grassland Fire Danger Index. Through our summer period, our grain harvest period, most, if not all, I'd like to think all, grain producers understand that there is fire risk. There's certainly many ways that we can manage that fire risk through mechanical things we can do on our harvesters and having firefighting units in the field, etc.

Leighton Wilksch:

Having local weather data information to help make decisions about that risk has become particularly important in a lot of areas. I've been quite fortunate that it's helped drive my business of having weather stations in paddocks or nearby, to help make those decisions, particularly after a run of harvester fires through the early 2010s. Having that information local and handy to make a decision, yes, I can harvest, or no, I can't, has been very important, I'm sure in South Australia in general.

Leighton Wilksch:

What I have here with this graph is showing a high risk day on the 6th of December. That was actually in 2018. Up at the top panel of the graph displays in the red the temperature of that day. In the black is the wind speed and in the blue is the relative humidity.

Leighton Wilksch:

The McArthur Fire Danger Index calculation is a few variations of that, but typically it's taking those three parameters. The Curing Index relates to how dry a fuel load is. In the case of grains harvesting, we make an assumption that it's 100% cured, basically because if it's not, we wouldn't be out there harvesting.

Leighton Wilksch:

Those four parameters go into the Fire Danger Index calculation. This is one of those extension calculations that takes place, in my situation, every 15 minutes. That's spitting out the blue line there, which is the Grassland Fire Danger Index.

Leighton Wilksch:

In South Australia, we have a threshold for our grains industry of 35 for the Fire Danger Index, which means that paddock activity should cease according to our code of practice. That means all gets turned off, no more harvesting, and essentially vehicles out of the paddock.

Leighton Wilksch:

What's interesting about this day I have displayed there is that the Fire Danger Index has actually crossed that threshold 12 times. It's gone over it and then under it 12 times throughout that day. Sometimes having information doesn't necessarily make making a decision any easier. But on this day, you can see there were wind gusts. The black line there, that actually caused that Fire Danger Index to go up and then it dropped off and it went down.

Leighton Wilksch:

Often I say to users that they really need to be looking at the steepness of the graph. And if you look around 8:00 AM here, you can see from 8:00 AM and in that morning, the wind speed has picked up and that Fire Danger Index has picked up a bit, started the crossing of that threshold numerous times. Then in the afternoon, the wind speed has dropped off and dropped right back down low again.

Leighton Wilksch:

The Fire Danger Index, as I said before, has become quite critical for a lot of communities to use, as individuals and communities to help them make decisions about the fire risk and whether they should or should not be harvesting. Inevitably, that has led to being involved with insurance and those that are pushing the limits too much of, a form of having information to be much more aware of the risk that is involved in still being out the paddock.

Leighton Wilksch:

This is just another way of displaying the Fire Danger Index information. On the left-hand side there, I've got a Google Earth map and whilst the numbers aren't very high there, it's just a screenshot of a particular day in April. It just shows how there can be variation in Fire Danger Index over a spatial area, similar to the temperature inversion map we were looking at before with the SA Mesonet. On the right-hand side, this is just a range of where the stations, a snapshot taken all at the same time, on a high risk day on the Yorke Peninsula. All those sites within about a 25 km radius of each other.

Leighton Wilksch:

The figures, you can see there, 25.7, 11.2, 49.7 and 20.7, just gives an indication of the spread of Fire Danger Index and how it changes going across the landscape. Again, driven primarily by wind speed, but also just the variations in temperature. In this case, a number of those sites are very close to the coast and humidity has an impact on that Fire Danger Index.

Leighton Wilksch:

Just moving to, I know we'll play this one a few times. This is I guess where a lot of weather station information is heading, I trust the video is playing. This is a dynamic layers showing change in weather information over a period of time. This was actually taken from this morning, working with a colleague who is helping putting together this software. Their readings of temperature from this morning and using some very clever interpolation algorithms behind the scenes. It's just showing, graphically, dynamically the change in temperature over every 15 minutes, that period of time.

Leighton Wilksch:

Where I find this becoming exciting is for things like Fire Danger Index, so you can actually see where the FDI has come from. You see in our situation, where a lot of our high risk events come from the west and they move towards the east, through South Australia. We can potentially see lots of input of weather station information, we can see the Fire Danger Index might potentially peak here on Eyre Peninsula, as it moves across the Yorke Peninsula and keeps moving across the state into Victoria.

Leighton Wilksch:

Unfortunately, we saw too many photos on Twitter and throughout the media of dust storms as they moved across South Australia into Vic and New South Wales over the last couple of years. I guess displaying Fire Danger Index information in such a spatial nature, or that dynamic change nature, will help those in front of these Fire Danger Index fronts, are coming from to help them make a decision, potentially even deploy resources to those areas that are going to need it most.

Leighton Wilksch:

Almost finishing up on the weather information. Site specific forecasting, where data from weather station sites is ingested. Observations from those sites are ingested, and help shape weather forecast. It is coming, and at it is here there's a range of companies that are doing that.

Leighton Wilksch:

I've been working with DTN is one of those. DTN is a U.S.-based company. They do a lot of this over in the U.S.A. and they have a presence here in Australia. So I've got a number of sites where they're ingesting information. That's putting back out site-specific weather forecast for that site. This is just taken from my site here at Paskeville, looking at the next few days ahead. Certainly had some challenges with this and just getting the databases all lined up so that one platform can talk to another. It has taken many months and too many hours of my time. I'd rather be out in the field doing that then in front of a PC.

Leighton Wilksch:

The process does seem to work. Whether the forecasts are any better than a whole range of the free forecasting sites we have here available to us in South Australia, I'm still evaluating. It's certainly a step in the right direction.

Leighton Wilksch:

Again, if we combine forecast models for things like Fire Danger Index in with the dynamic display I was showing you in the slide before, we can potentially have a look ahead function for where Fire Danger Index or where frost might go in the next few hours, where temperature inversions might potentially go in the next few hours to help us make decisions. The more data points that feed into those models, the sharper and more accurate those models will get, to help make those management decisions which can potentially become a very powerful tool.

Leighton Wilksch:

We're going to move on now to soil moisture probes. I've often said I'm not real smart, but I'm really good at digging. That's what I spend a fair bit of my day doing all day, is putting in soil moisture probes, primarily in dryland ag. I do have a presence in viticulture as well, but 95% of the probes I put in are in dryland ag.

Leighton Wilksch:

Not everybody finds the data, the information from soil probes useful. Some sites probably haven't been selected well. Some sites, the installation hasn't been great. Others just find the information after a number of years, it really isn't telling them anything particularly new. Often that's been the case where we've had a run of dry years in a row and the information can't help them make decisions. But I'm just talking about a minority. I'd like to think that the vast majority of users of soil moisture information still find that data handy for making decisions.

Leighton Wilksch:

A lot of that is around this time of year where we can look at infiltration from rainfall events in autumn to help us make decisions about when and what to plant. But obviously the big ticket item is as we go through the growing season, towards the pointy end of making nitrogen management decisions, should I or shouldn't I, as we go through grain fill in that July, August, September period. That's where I find customers get the most value from the soil probe information.

Leighton Wilksch:

Where to actually put a site is often related to where there's a fence, or tracks, or trees. We need to obviously keep away from tree lines, or where there's any preferential flow off of a track or a gutter. Soil probes are put in all subsurface, so we need to be conscious of tillage and how deep tillage might occur. I generally find that growers think they till deeper than what they actually do. Most of my sites, the top of the sensor, or top of the probe is at 10 centimeters. I've certainly got a few using Conserva Pak or DBS with longer points. So you're down to 15 centimeters with the top of the probe.

Leighton Wilksch:

Again, on the other side, on the flip side with those using disc seeders, I've got some sites where the top of the probe is only five or seven centimeters below the surface. So we can get that top sensor up as close to the surface as possible and measure the infiltration from that top layer.

Leighton Wilksch:

As you can see by the photo there, I've got a narrow trench with a very ugly, horrible thing to use called a terra trencher, which is basically a chainsaw with a saw trenching chain on the front of it. In good soil conditions, that works exceptionally well and allows me to trench out from the fence to where the soil probe is and have minimal impact on the crop. As you can see, that one has gone into a barley crop there. I do have large feet, but I'll manage to not step on the barley and get that probe in the ground, minimal disturbance to the roots, so essentially data can come from that probe.

Leighton Wilksch:

Then once the slurry has dried down, which might take one to two days, then the information from that probe comes essentially straight away. Then we can get some data that can help make decisions and see where roots are growing, too, when extracting soil moisture.

Leighton Wilksch:

Most often, clients are using one soil moisture probe on their farm. Over time, that might expand to two or three. When I'm asked where should I put it? Often, that is in the median soil type, what you have most of on your farm. Also, related to that is where are you going to get the best return on investment for your nitrogen application. Soil probes don't make the decision for you, but they can help make a decision as far as where has soil moisture gotten down to, where are roots extracting from. Putting a probe where you're going to get that bang for the buck is probably the best choice there.

Leighton Wilksch:

I often find that in the second or third year, a grower will put in another soil probe, and that might be in a different or sandy soil type, or one that's more rocky and has less plant available water content.

Leighton Wilksch:

There are a number of ways that soil probes can go in the ground. I've learned through trial and error what works for me. I adapted that for different soil types. A lot of the Yorke Peninsula is a clay lime over a rubbly limestone layer, so busting through rock and getting a soil probe installed in those situations, so you can get valid data from it, is as I said, it's been a trial and error to get to where I am now.

Leighton Wilksch:

Sandy soil types, Wimmera self-mulching clays, they all take a bit of a technique to get the probe in, so you can get data that's relevant and useful, in the first week pretty well.

Leighton Wilksch:

Sharing data with neighbors, too, has been very valuable where two or three or five neighbours might go in with a soil probe and a weather station each. And they're sharing that information to compare and contrast what's happening with each one of those probes. Looking at different crop types, one farmer will have one in wheat, another one in lentils, another one in canola. Just to see what's happening in each of those fields and interpolating that information back to the home farm has been a very useful way to get more value for a site that's installed.

Leighton Wilksch:

I'm just going to display some soil moisture probe graphs, which show information current to this morning. There's plenty of different soil moisture probe platforms out there that display data.

Leighton Wilksch:

I've looked at quite a few of them and for me I've settled on the program I've always been using, which is Sentek's IrriMAX software. I do find it's very intuitive in the way it displays data. It also allows me to cut out erroneous bits of information, so that where there's gaps, we can join them up.

Leighton Wilksch:

Also, a recent addition in the last couple of years has been putting in soil temperature compensation. So soil temperature does have an impact on capacitance of soil moisture probes. As we increase in temperature over summer, often it looks like there's an apparent increase in soil moisture, particularly in soils where there's high ion content. So salts at depth and most often that is in the sensors that are the 90, 100, 120 centimetre sensors.

Leighton Wilksch:

By being able to compensate and measure that soil temperature and compensate for soil temperature impact, that's been a really useful tool to give information that's more true to what's actually happening.

Leighton Wilksch:

The graph I have there has sensors, the top sensor's at 15 centimetres. This is at Tatyoon in Victoria. The red line is the 15 centimetre. Then we go down through the profile and end up at 125 centimetres, which is the pink line. Just some interesting things to take from that graph there. This displays 365 days. The figures on the left-hand side are the millimetres of soil moisture for each sensor, 365 days ago. On the right-hand side you can see those figures which show where it is now.

Leighton Wilksch:

Some things we can actually see from that was a reasonably wet winter going through June and July last year. And a lot of the top layers down to about 65 centimetres were saturated. When the year two, for a lot of that time, we had some rainfall events there in June and July which then soaked a wheat field down to 125 centimetres and below.

Leighton Wilksch:

What's interesting to note with that pink line at 125 centimetres is that has stayed flat, which means the moisture that fell last year during winter is essentially there now and available to help fuel this year's crop.

Leighton Wilksch:

What we can see, this was wheat that was planted and through October and November, we can see the diurnal stepping. So that's the little incremental daily steps, where the plant is transpiring and pulling moisture out. Then during the nighttime, that stops, so the step levels out and then it goes down again. What we can see is that stepping occurring, particularly through October there, as the roots from the wheat went down through the profile and pulled out moisture.

Leighton Wilksch:

What is quite noticeable here is the 65 centimetre line. There's some really big steps towards the end of October. Then just shows how many mills of moisture from a large crop can actually be pulled out and extracted.

Leighton Wilksch:

Then it's also interesting to note, as we went through November, there was more rain at the start of November, and whilst it didn't actually infiltrate. There's very little infiltration evident at the 15 centimetre sensor. Mine has actually leveled out here, when looking at the 65 and 85 centimetre sensors, even mine's gone flat, which means that the moisture was more available or easier for the plant to utilise at the top, rather continuing to pull it from the lower layers.

Leighton Wilksch:

Those layers then leveled out until all the moisture had been exhausted at the top, and then the roots start pulling again as we moved into December. They got down to 105 centimetres at that site last year.

Leighton Wilksch:

Move over to the right-hand side of the graph. Recent rainfall events through April and into May have been quite fantastic across a lot of southeastern Australia. So we're seeing infiltration go down again. In this case, at this site, it's gone down to 65 centimetres, with the rainfall events in the last five weeks.

Leighton Wilksch:

Just showing some of the anomalies or weird things that happened in soil moisture probe graphs. I've got a 60-day graph stacked. This is a different site, but still at Tatyoon in Vic. This is just the last 60 days. Got a couple of blue arrows there which shows deep seated soil moisture, even though you would think the lines should actually be going up. This is one of the weird things that happen as moisture infiltrates and percolates down through soils, particularly soils that have got a higher clay content.

Leighton Wilksch:

In heavy rainfall events, that wetting front as it moves down actually traps air and increases air pressure under ground. As the water goes down, the air can't escape. Air can't escape quickly, it does over time. But as that air gets pushed downward, the pore space between the clay particles expands, more air gets in between those clay particles. Therefore, the soil sensor thinks relatively there's less moisture in amongst those clay particles because there's more air.

Leighton Wilksch:

These heavy clay soil types with heavy rainfall events, we do get these situations where the graph actually dips before coming back up again. It can come back up again as that air starts to equalise out and move up through the profile and can't move down.

Leighton Wilksch:

Particularly on the right-hand side there, that in this last week, there's been some noticeable downward movements before the probe, before the sensor line goes up. You'll see the 105 centimetre sensor in the dark purple has gone down and that whole line, I expect in the next couple of days, will start to shoot up again.

Leighton Wilksch:

All the stacked sensors, show all the individual sensors going down through the soil probe. I should say that typically I install 120 centimetre soil moisture probes. When we add up all those stacked sensors, we end up with a summed graph.

Leighton Wilksch:

The way I display my summed graph information is by stacking, sorry, by putting panels from previous years on top of the current year. In this situation down on the bottom panel, this one here I'm highlighting with my mouse, this is the current year and then the line in the middle panel is last year, and the year before is on the top panel.

Leighton Wilksch:

Essentially that black line moves from left to right and then joins the panel below. As we can see, the line over here in the top panel on the right-hand side then joins the middle panel on the left-hand side here. It takes a little bit of time to get your head around what's going there, but once you do, it becomes quite intuitive. You can see where soil moisture was at the same time last year and the year before.

Leighton Wilksch:

In this graph here, I've put some comments in there about what crop type has been planted. What's quite evident there is as we move through 2018, in Minyip there was very little rainfall and very little infiltration. The wheat didn't have a lot of moisture to extract. 2019 was a wetter year and we can see the summed graph moved up, certainly not to the full point. We saw the full point in 2016 at that site.

Leighton Wilksch:

Last year, we saw the barley extract the moisture down to the driest ever point. Essentially it sucked all of the moisture out for that 20 centimetre profile. Since December, we've had a number of rainfall events that has gone towards filling that profile up again. We now know that fuel gauge view is sitting out essentially 40% full with the soil moisture profile in the top 125 centimetres.

Leighton Wilksch:

That is really useful information for planning planting this year and also potentially understanding what that can mean for rain fill later on down the track. What that might mean for estimated crop yield and leading on from that, grain marketing.

Leighton Wilksch:

I just thought I'd put this one up here for interest's sake. The York Peninsula is know a quite a reliable area, but there's certainly been plenty of places on the YP that have received very little rainfall in the past three or four years. This graph highlights how that has been. It certainly has been quite amazing, what with being able to produce with such little in crop rainfall.

Leighton Wilksch:

But 2018 and '19, you can see that the infiltration has been very little during the winter period there. A lot of those lines are very flat as we move from summer into autumn. The last three years has been quite boring, as those lines have remained so flat. Fortunately in the last two weeks, we've had some wonderful rain, 60 to 70 mills, and that has infiltrated down through the profile.

Leighton Wilksch:

If we look at the bottom panel, we can see that infiltration has essentially gotten to a point where we were at the wettest point in winter last year, which is exciting, we've got a forecast for an average winter rainfall coming up.

Leighton Wilksch:

Soil moisture probe graphs can also throw out some really interesting information about summer weeds. This is a site, again at Tatyoon, from December, January, February 2018. It was a canola crop in 2018. Naturally with a lot of canola crops, you get some shattering. Canola falls on the ground. A very heavy rainfall event, December 15 in 2018 and I've got a blue arrow there showing that rainfall event and the infiltration actually got down to 105 centimeters. It fell very heavy and very rapidly. Of course, that rain germinated canola and other weeds, I would imagine.

Leighton Wilksch:

I looked at this probe graph and communicated with the grower and the agronomist to see what was actually going on there, because I noted the diurnal fluctuation as we moved through January, which showed root activity. Those roots from the canola went very rapidly down through the profile.

Leighton Wilksch:

As you can see, I've got a comment there that approximately 60 days after that rainfall event, the roots had hit 105 centimeters, which is quite mind blowing, how quick some of these summer weeds can grow. I've seen that in other situations before with things like melon, and cowtrop over the top of a soil moisture probe, when we get the suitable rainfall conditions, that those roots can move very rapidly and suck a lot of moisture out of the profile.

Leighton Wilksch:

In the case of Tatyoon, that probably wasn't that much of an issue. Most winters, they get to saturation or near saturation, so starting the growing season with a drier profile can be handy, but for most areas in Australian ag, dryland ag, of course you want to retain as much autumn and summer rainfall as possible, so controlling those summer weeds seems quite critical.

Leighton Wilksch:

Getting close to the end now. Just want to update a little bit on the status of networks for communication across Australia, in regional areas. As I mentioned before, I run almost exclusively, all of my sites on the Telstra 3 and 4G network, essentially because it's got the greatest coverage. Whilst I have ample frustrations with the network with outages, 95% of the time, 99% of the time, it's actually running very well, and I'm very thankful for the coverage we do have. It does provide a great service to be able to push information through such a network.

Leighton Wilksch:

Many would be conscious that 3G is being phased out Telstra said by 2024. Many will remember the 2G phase out and just having to swap over phones with that. Most would have phones that have been 4G enabled for many years now. So phone swapping isn't going to be a problem.

Leighton Wilksch:

But there are thousands and tens of thousands of loggers that have 3G modems in them and dealing with that is something that the industry is going to have to sort out. That's not only weather stations and other loggers in the field, but things like vending machines and ticketing machines, all sorts of things are still running on 3G.

Leighton Wilksch:

Swapping over modems, and swapping over the telemetry systems is going to be quite busy for people over the next three years. That's a process, personally, I've already started to head down. So 3G phase out by 2024.

Leighton Wilksch:

I've certainly noticed the quality of the 3G signal dropping off in certain areas where maintenance of towers has not been kept up, obviously, because there's been a focus put on 4G and now with 5G coming, too. I've moved across at the start of last year, I'm phased to move across to utilising Telstra's 4G Cat M1, Narrow Band IoT, Internet of Things network. It's the 4G NB IoT. Lots of capital letters in there.

Leighton Wilksch:

What that essentially, that network is, it runs parallel to the 4G LTE network that you use for your phones and your download communication. But the Cat M1, is a much slower network and is set up not for voice or for large amounts of data, but set up for loggers that are pushing through small bits of information, bytes, and kilobytes and bits of information on a regular basis.

Leighton Wilksch:

I now have about 100 units running on that 4G NB IoT network. Certainly came with quite a few headaches last year, just getting the modems to be able to connect like I would like to be able to push the data through regularly. But most of the bugs have been ironed out now and I'm really excited about the use of this Cat M1 network.

Leighton Wilksch:

One of the great things about it is that range extends far beyond what your 4G tower with your phone can extend. I've got some sites that are out at 60 kilometers from the tower. They do have directional antennas. I'm aware that Telstra has actually being able to have some sites where they're pushing out to 100 kilometers from a tower, and so being able to push through information.

Leighton Wilksch:

Whilst there are other networks out there, and I'll talk about them Low Earth Orbit and other ones in a second, whilst there are other communication networks out there, I have personally invested in Telstra 4G Cat M1, and that is now going to be the mainstay for how I get information from my weather stations, soil probe networks, to a server.

Leighton Wilksch:

So 5G is being talked up a fair bit on adverts on the television. I find that a bit frustrating because we don't have 4G connectivity in regional areas up to the standard where I think suitable, and yet, we're already talking about 5G.

Leighton Wilksch:

It's certainly something where that is going to fit in in regional areas. I have question marks because 5G signal distance is far and away less than where 4G is at. Whether we need to have a whole heap more towers if 5G connectivity is going to be a thing in regional areas or not, wait and see.

Leighton Wilksch:

LoRaWAN is a term that some of you would have come across. LoRa stands for long range, WAN is wide area network. Essentially this is one of a number of types of networks where there is a base station. And that base station is connected to the Internet, whether it's through the Wi-Fi network in your farm yard or your house, or whether it's actually got its own standalone connectivity to a Telstra network.

Leighton Wilksch:

But that base station then has lots of nodes that connect it to the base station. Those nodes are typically in an area, a radius of five to 10 kilometers from that base station. Those nodes connect exclusively to that base station.

Leighton Wilksch:

On each one of those nodes, they can have a logger or loggers and so that might be a rain gauge or a tank level sensor or a flowmeter. Those little nodes log the information in on a prescribed connection interval. That might be 15 minutes, it might be an hour, it might be two hours, they will push through some bytes of information.

Leighton Wilksch:

Often these LoRaWAN networks, they can only be very small packets of data. Often the loggers don't actually store the information for longer than say an hour or two hours in 24 hours. So if there's a breakdown in connectivity, information can be lost, which can then become problematic for higher value data, such as soil moisture probe or temperature frost monitoring. But there's lots of things that we can log information for where breaking transmission or breaking data isn't actually that critical. So tank level sensing might be one of those.

Leighton Wilksch:

We are seeing more of these LoRaWAN networks being set up. Certainly state government departments have been quite instrumental in getting them underway with varying levels of success.

Leighton Wilksch:

I guess my take on the LoRaWAN radio networks at this point is that if you are a farm business that really is only looking at sensing one or two or five things on a farm, over a 10 to 15 km radius, then still using something with a SIM card in it is probably going to be cost effective.

Leighton Wilksch:

But where we move into more intense ag, such as feed lot or livestock, or viticulture, irrigated ag, where we could potentially think about tens or dozens of things to be sensed, and the return per hectare is also increased, then LoRaWAN networks, I think, are going to have quite a large fit.

Leighton Wilksch:

Myriota is a company, Adelaide-based company, that is utilizing low earth orbit satellites. They're one of a number of companies out there now offering loggers that will log information from say, tank level height and use these low earth satellites that might pass once, twice, five times a day, push the data through to them.

Leighton Wilksch:

Again, very small packets of data going through each time and then goes through the satellite, picked up on a server and can be displayed until used. A very remote thing, such as a tank or a trough, where that critical bit of information is up to. Again, there's been some teething issues with that, but for the most part, I think they're underway and running well. So options out there with Myriota.

Leighton Wilksch:

Similar to that LoRaWAN, is other private and public radio gateway networks that are underway. Some of them are quite proprietary. I don't know a lot about them, but these proprietary networks, you've essentially got to buy the sensors and the nodes and everything through the same station. That information is all locked down, so we can't put in third party sensors. It's very hard to put in third party sensors to feed into those proprietary networks. But some of them are out and about in Australia.

Leighton Wilksch:

For me personally, I'm always looking at what other options are out there. But as I'm primarily based in dryland ag, looking at broad hectares having monitoring sites with a SIM card connected to the 4G Cat M1 network, suits me at the moment.

Leighton Wilksch:

That pretty well wraps up my presentation. Thanks very much for listening in. Happy to take some questions there. There's just some details of me and thanks very much to AgVic for asking me to be involved. And hand back to Alice now for some questions.

Alice Ritche:

Fantastic. Thank you so much, Leighton, that was a really great presentation with a lot of practical insights. I love all the examples.

Alice Ritche:

I think a lot of people will be exploring weather stations and soil moisture probes for their own situations now, so it's been really, really great.

Alice Ritche:

We have had a lot of interest, got 148 registered and 71 participants online, which is probably an indication that we've got some pretty nasty weather on its way and people are out on their tractors at the moment. But they will be listening to the recording, I am sure.

Alice Ritche:

Just in the interest of time, we've had a couple of questions come through, which I will ask you. But would you be okay if people got in touch with you directly, either using, I suppose the communication channels you've got on your screen at the moment, Leet? www.agbyte.com.au

Leighton Wilksch:

Absolutely. No worries.

Alice Ritche:

Fantastic. I'll get started, we'll just do three or four and then we'll be done.

Alice Ritche:

We'll just say for anyone who would like to listen that has to go, the recording will be sent out and you will be able to listen to these, so don't stress too much.

Alice Ritche:

A quick one around the soil moisture probe data that you had up, around Tatyoon. Is that data publicly accessible or is that for individual farms? What's the different options for people when accessing soil moisture data?

Leighton Wilksch:

Those sites, they are private owned farms, so that's not public information. I have very few sites in Victoria that are public, but yeah, certainly with the farming systems groups in South Australia, we do have a number of public sites.

Alice Ritche:

Just to add to that one, if you tune in, for everyone listening in about a month's time, our next webinar, we will be having a webinar around the Victorian soil moisture monitoring network. There are some public sites. We're relaunching the website. It's going to be really, really fantastic. Just hold onto your hats for that one.

Alice Ritche:

A question from Robert Connor. Do you use any of your weather stations to measure evapotranspiration, and if so, how have they performed?

Leighton Wilksch:

Yeah, I saw the question pop up, Rob. That is something I have done at a number of sites, the ETO, more so for the irrigation sites. But it is something I do want to spend a but more time focusing on particularly in dryland ag, because it is a useful tool. If we can incorporate forecast conditions and look at where ETO is going, that becomes quite powerful, particularly during that spring grain fill period to understand where can I be in a week's time. I have done a little bit, but not enough with ETO.

Alice Ritche:

Neil James asked a little while ago, we were talking about soil moisture monitoring, and particularly the charts and the graphs. How do you know how deep the roots have got? Is it only by where you get less moisture at depth, or are you actually doing a dig?

Leighton Wilksch:

No, I don't do a dig. I did say before, I'm not real smart. I'm not good at digging. Because getting in the paddock to understand how deep roots have gone is often at a time when there's crop everywhere, so you can't do that. But look, for the most part, if he's looking at that diurnal fluctuation and just seeing where that root activity is underway, and with soil types, we've got a pretty good gut feel for how deep roots are going.

Alice Ritche:

Fair enough. I think that will probably cover off on the questions that we've had at the moment. Neil had another one on community weather stations or monitoring stations. How would they work or how do they work and how do you find out where they are? Do you know anything about community weather stations, or is that something where you should investigate for a future webinar?

Leighton Wilksch:

Look, my website, the front page of my website, I've got all the community sites that I have. I know various NRM boards have their weather station networks up. I guess a Google search in your patch will show you where community ones are. Often I've found community ones are great, they provide fantastic information. But for someone that's even five or ten kilometers away, you always go, "I wish I had one closer," which has been great for my business.

Leighton Wilksch:

Weather data can be so specific that, depending on landscape, once you start to get a few kilometers away, it can become less relevant.

Alice Ritche:

No, that does make sense. It harks back to your earlier slide around how much variability there can be within a small area.

Alice Ritche:

One last question, Rochelle Mayer has asked, "How hard is it to get temperature, humidity index in the weather station display?"

Leighton Wilksch:

Hang on, not quite sure exactly what that question is.

Alice Ritche:

That's all right. Rochelle, would you like if I might unmute you and we'll see if you can ask that in person, if you like. I'll just let you out. Rochelle, you should be able to speak, if you'd like to. She's not there. That's okay.

Alice Ritche:

Dale Grey has got his hand up, so I suppose we better unmute him and see what he would like to ask. Let's do this. Dale, can you speak? No. That's okay. I think, given technology, I reckon we might call it a day.

Alice Ritche:

Thank you very much, Leighton. That's been a really, really fascinating talk. I'm sure lots of people will be listening in to the recording as well.

Alice Ritche:

Thank you. For everyone who is still listening in, our next webinar will be in a couple of weeks' time. Everyone who registered for this webinar will receive an email with details closer to the date. Make sure you check your inbox for an email from climate.webinars@agriculture.vic.gov.au. Or you can check out our website at agriculture.vic.gov.au/climaterisk, for more information.

Alice Ritche:

Thank you very much. I think we've all had a fantastic time. Cheers.

Page last updated: 03 Aug 2021