Topsoil mapping in the Mallee

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Tanja Morgan: Welcome to the MSF Farm Talk podcast. I'm Tanja Morgan, and today we're going to be talking about diagnosing sandy soil constraints and using new technology to find out more about w here we get the best impact from any sort of soil amelioration that we are doing. So, I'm joined by Michael Moodie. We’re sitting in the cafe at Lameroo, how are you going Michael? What have you been up to today?

Michael Moodie: Yeah. Today I’ve been out sampling to basically validate the mapping we've been doing in the area to see how deep the sand is or where the clay layer is in the paddock to try and help some farmers over here guide where they might be undertaking soil amelioration activities soon.

Tanja Morgan: It's one of those questions that keeps coming up. People know that they're getting a response from ripping, but still unsure where to start and stop. So, this project that we're working on, it's all about building [00:01:00] knowledge and capacity in growers to diagnose sandy soil constraints, and this is really trying to help them understand where to start and stop when they're doing their ripping. So, you've got a new machine that you've built. Tell us about that.

Michael Moodie: Yeah, so we’re, building a machine, I suppose we are acquiring some equipment and sticking it on a Polaris side by side, to do some trial based activities with, but in some of the trial work that we did, part of our work within the GRDC Sandy Soils project we really started to see that the uh, response to soil amelioration, whether it was deep gripping or spading or other activities like that was pretty well correlated with your different soil types in the paddock.

So, where we're getting the biggest response, seems to be on those sort of deeper sand soils, which was the poin t of doing the project in the first place. And as you move off those sandy soils onto the heavier soils within the paddock. We've got a few sites now where we're just not seeing as big a response or any response in other soil types. We've seen that it's correlated well with [00:02:00] EM mapping. So, we've known for a long time, the EM 38 mapping works well to define soil zones. And that's what we're looking at in this project to see how well it defines where soil amelioration activities sho uld be undertaken.

The device that we're using is called a topsoil mapper, and how that differs from a normal EM 38 machine is instead of just measuring the average conductivity level of the soil, it's got one emitter and four receivers. So, it's actually mapping the conductivity of the soil in different bands going down the profile.

So really, it's about trialling to see one, how well the EM38 actually correlates with the responses that we're seeing to soil amelioration. But two, can we take that mapping EM 38 mapping one step further and actually be able to predict where that depth of sand is or where that depth of clay is in, in the paddock to not only guide the soil amelioration [00:03:00] activity, but maybe the type of machine that you might want to use at different spots in the paddock.

Tanja Morgan: So is it giving us a bit of a prediction on where we might see compaction?

Michael Moodie: Yeah. So the other thing we're doing to link it up is we're. Haven't quite got it yet, but we're awaiting an automatic penetrometer. Now we encourage people to use penetrometers which are just handheld machines, which means you've got to get out probe around and get a reading.

Download that data. This penetrometer that we're trying to set up will be automatic on the Polaris. You pull up on the spot press a button and the process happens automatically and all the data capture happens automatically. We are looking to see whether this machine might actually add value being able to maybe take a grid-based approach across your sand.

You know, take a lot more diagnosis measurements by using an automated process rather than a manual process as it is now. So, the two are going to work hand in hand together, basically the EM mapping to try and identify where the sands are. And then once we've identified where the [00:04:00] sands are, the automatic penetromemeter to go in and try and measure what sands, have compaction problem or a hard setting problem, and which ones don't.

Tanja Morgan: And this year we're also setting up several demonstration paddocks that have been mapped with the top soil mapper and hopefully the automating penetrometer. So, what have you got in the plans for this year with your demos?

Michael Moodie: Yeah, so we've done two paddocks so far.

We've haven't got too many formalized results from these activities yet. We've got a lot of data that we've got to wade through and see how well it works. But

we've got another four paddocks to do. Later in the year as well. Yeah, really trying to demonstrate this and we're trying to demonstrate it at the broad acre scale.

So we're not working on little research plots. We're working to try and measure and validate paddocks as we go.

Tanja Morgan: A machine like that is something that, somebody could set up in the district and a lot of people would have access to that, which would make it easy. Have a better idea of how to get the most out of your saw amelioration strategies.

So it's pretty exciting stuff. This project also looked at the Sandy Soil Masterclass [00:05:00] activities and the soil pits. And I know that you took a whole pile of 360 footage of that. How can farmers get access to that?

Michael Moodie: Yeah, so I think as part of those masterclass events, we took some, footage and we're putting some information together currently on a website that's quite a way through development now

What we are hoping to see is for those people that couldn't attend the master classes or maybe those people that did and want to revisit, we're trying to take the soil pits and the masterclass to you via online mechanisms, apps and also the website. Hopefully the 360 tours allow you to jump into the soil pit that's going to be supported by voiceovers, and analysis of that soil pit.

Look at what are the constraints in each of the soil pits, what are the key features that you need to look at? And hopefully by having access to these, I think it's six different soil pits. You'll get a bit of an understanding of what you need to do on your own farm to diagnose your own constraints.

So as much as they're about, demonstrating what was happening at the [00:06:00] masterclass events and what was happening at pits they're also hopefully going to give growers a bit of a guide to what things they need to look out for in their own soils to work out what problems that they need to address.

And then hopefully give you the knowledge to go away and select the right tools for the job. Again, that's something that's going to happen in the hopefully the first half of this year.

Tanja Morgan: MSF and Frontier Farming Systems have been working on a number of different projects, looking at Sandy s oils for the last few years. Have

we discovered everything we need to know? What are the things left that we still need to focus on going forward?

Michael Moodie: I think it's a bit of a tip of the iceberg approach. you know, we’ve discovered that there's some good options there for farmers to actually, to improve productivity on sandy soils, like it was a major issue within, the MSF membership only seven or eight years ago. How do we improve production on these sandy soils? The GRDC funded Sandy Soils project, which was in collaboration with a whole group of other groups led by CSIRO has really demonstrated that there are options out there.

But I still think [00:07:00] there's still a lot of work to do on how far we extend the amelioration options off the sandy soils into the rest of the paddock. How do farmers do it and overcome the challenges logistics, you know, running sprayers and seeders and controlling seeding depth and all those sorts of practical options.

But also, there's some work to do around what we're effectively doing is setting a new yield potential. And so that new yield potential needs to be met by things like inputs, like nitrogen things like which crops and varieties are responding better than others.

And how often do we need to go back and ameliorate these sands? These are all big questions that are really going to affect how profitable it is for the farmer at the end of the day. So, I think there's some more work that can be done. it It’s a high cost or relatively high-cost operation to ameliorate our sands.

So, we want to nail down what are the levers that need to be. To make sure that it's the most profitable outcome that can occur. Because if we don't maximize the benefit or maximize the return that we can get from that operation, you know, it can, it can very [00:08:00] quickly become a bit of a cost negative event.

And that's been demonstrated through the Sandy soils project. A lot of our trial sites have had highly profitable returns from amelioration but there's also been some trial sites out there where it hasn't been as profitable, so we really need to focus in and work out what are the factors that need to happen to make sure that it is a profitable outcome when you go into soil amelioration.

Tanja Morgan: It is still a priority for our growers. So, we're not going to give up on it just yet. Watch this space. We're looking forward to where we can take this in the coming years. So, thank you very much for joining us today and

giving us a good summary. We'll be following those demonstrations throughout the year and hopefully we'll be able to see some footage of the topsoil mapper in action.

Yeah, thanks for joining us.

Michael Moodie: No worries. Thanks Tanja. And I'll finish my coffee.

Tanja Morgan: Excellent. Leave you to it.

This project is supported by Mallee sustainable farming with funding from the Australian government's national Landcare program and the grains research development corporation.

Tanja Morgan: Thanks for joining us. If you wanna hear more like and subscribe to the MSF Farm Talk podcast. [00:09:00] Catch you later.