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Episode 5: Mallee Farming AgVic Series | The way forward with Rob Norton

March 26, 2020 - 11:56 pm

Rob Norton from Norton Agronomy joins Drew Radford to discuss the nutrition status of soils following successive dry years and rehabilitating soils that have experienced wind erosion. Rob outlines weed control decisions, planning ahead, minimising stress, gathering information to make critical decisions plus much more.

Podcast Transcript

INTRO - Welcome to this podcast, brought to you by Mallee Sustainable Farming and Agriculture Victoria from the MSF Research Update at Lake Cullulleraine in February 2020

  • DREW RADFORD - Forward planning does not necessarily mean deciding what to do, it means deciding where the decision points are that you're going to make and what the options are. That's the view of consultant agronomist, Rob Norton, who joined me in the MSF podcast studio to discuss how understanding your soils is crucial in forming those decision points.
  • ROB NORTON - Well, I suppose the first point is, what's done is done, we can't do anything about the past. What we're going to look to do is to plan for the future and that planning really needs information and so the second point is you need to know what your soil is doing. And so, soil testing is critical to know what nutrients are there, what sub soil limitations are there. The third point is with the rain that's been through some of this part of the Mallee, we've got to think about weed control. We've been given this water, we don't want to waste it by letting weeds grow, so the third point is a keep the resources that we've already got.
  • DREW RADFORD - Just on that third point there, in terms of weed control, there must be fine line to, yes, obviously they're robbing you of resources, but soil management is also a big part of this picture as well.
  • ROB NORTON - And it's one of the big decisions about whether to control those weeds on paddocks that are likely to blow again or whether to leave them there and help hold the surface. In reality, I think controlling the weeds is probably more important than trying to preserve what's there. You know, it's not always likely that we'll get big dust storms, big soil erosion events now, wind erosion and we may get water erosion events on some of the sloping land, but I think getting rid of the weeds is probably more important than really concern or worrying about the wind erosion.
  • DREW RADFORD - On that wind erosion point, you're saying that we got to move into different weather patterns now, so you think the big blows are done is that, is that what you're feeling is?
  • ROB NORTON - Well, very difficult, it's very difficult to predict the future.
  • DREW RADFORD - Indeed, that's why I asked the question.
  • ROB NORTON - You know, it's a judgment that growers have to make on their own feeling. You know, whether the bunions are hurting or whatever's happening, you know, they have to make that decision on whether they think they'd like to preserve that moisture more, or whether they think that another blow is going to come and move a bit more soil around. So, I can't make that decision for them, but the decision is, there's a decision point they have to make and most growers I think is spraying out.
  • DREW RADFORD - On your first point, what's done is done, is this the heart of that business planning and also letting go what's happened.
  • ROB NORTON - You can't look backwards and try and unmake a decision that you made, you know, last Spring or last Autumn. All that gives you is anxiety and really the anxiety in farming often is a major issue because we're always at the mercy of the weather and the markets and politics, etcetera. So, the moral is worry about something you can do something about, and really you can't do anything about the wind erosion that's occurred. You can maybe clear some tracks off, but really, you've got to look to the future and look forward. In terms of the decisions you can make, and those decisions are about the crops you can select and the fertilizers and agronomic programs you can use.
  • DREW RADFORD - I read a quote of yours saying, losing just one millimeter of topsoil can result in up to 6% yield loss, so is one of your messages about forward planning?
  • ROB NORTON - Absolutely, and forward planning doesn't necessarily mean deciding what to do. It means deciding where the decision points are that you're going to make. So, and what the options are, you can't make a decision with no information and most of our agronomic decisions rely on when the rain comes, what the soil test values are, what the disease status is, what our financial position is. So, there are decision points that need to be made and you'd like to make them with some information. So, knowing about what sort of stored waters in the soil, knowing what fertility levels are in the soil, that's critical information on which the decisions can be made.
  • DREW RADFORD - Are you still having trouble getting that message out though that you need more information, not less?
  • ROB NORTON - I think growers are really sponges for information, a lot of information actually doesn't translate to knowledge and a lot of knowledge doesn't relate to decisions. So, I think the key thing sort of as a scientist is actually to try and frame things in terms of what the decisions are and what the knowledge is needed to support those decisions.
  • DREW RADFORD - So in terms of some of those decisions and knowledge, what are some of the things that you've been talking about today?
  • ROB NORTON - One of them is about nitrogen status, what's the nitrogen status of the paddock. Each paddock is going to be different, each part of the paddock is going to be different. The dunes are going to be different to the swales and the data we've got from the soil testing program shows that there's significant amounts of nitrogen in the profiles. Enough at least for two ton weed crop, so that information helps us understand that really, we can defer a decision about nitrogen until in crop. So that's one of the examples of how we can use the information from soil testing to make a decision about fertilizer management. If the season becomes, you know, if the yield potential is more than two tons with nitrogen, we're lucky we can go back in and top dress, add additional nitrogen. Well, I think one of the key things that I mentioned in my talk is that use a test strip across the field, so put a strip of nitrogen out at seeding and just see what the responses are and use that as a gauge to whether the crop needs more or less.
  • DREW RADFORD - That's a long-term thing though as well, I would assume in terms of, you know, it's not just this crop, but that's going to give you a better gauge of what's going on in your paddock long term.
  • ROB NORTON - That's true, but I mean, there's always a short term and long-term view. The short-term view is we're going to make this year as good as we can, and the long-term view is using nitrogen in these environments here largely preserved from year to year. We did some farm surveys through the Mallee in 2014 to 2016, looking at nutrient balances in paddocks. One of the things we found was that a lot of farms were removing twice as much nitrogen as was being added with fertilizers and legumes. So, those paddocks are running down soil organic matter, which is the sponge which holds nitrogen and then provides nitrogen. So, there's a long-term view about nitrogen management, which goes to rotations and then there is a short-term view about supplementing deficiencies with fertilizer nitrogen.
  • DREW RADFORD - I understand from some of your work also, that there was a result in terms of nitrogen that you found that the level of nitrogen following a dry can often be underestimated.
  • ROB NORTON - Absolutely. Yeah, nothing's been removed, nitrogen processes mineralization from the previous Spring can still be there. Fertilizer nitrogen in dry environments can largely be preserved from one season to the next, if we've had a dry summer and a dry spring. The big issue with nitrogen is the potential losses, where we get the losses would be if we get a really a flooding, higher level of rainfall causing ponding and so forth, that causes denitrification, which causes the nitrate to be turned into nitrogen gas and so it's lost and that's one of the main pathways that under warm moist soils with high organic carbon we can get a lot of nitrogen loss. I'm not sure that would be the situation up here, soils are a lot lighter, so they don't get waterlogged. But what can happen with nitrogen in those situations with a high summer rain, is it can be leached to a below the root zone.
  • DREW RADFORD - I read an article that said to obtaining professional advice to interpret soil test results is critical to maximize the yield potential by ensuring the optimum fertilizer program is put in place for your soils. Do producers get the soil tests done, but don't then get professional help trying to interpret those and apply those?
  • ROB NORTON - Yeah, I think sometimes growers will have a soil test done. They get the results back and they really don't know how to interpret them and that's where Fert care accredited advisors come in and that's the standard for interpreting nutrient information, soil test information into fertilizer decisions and that's where, I mentioned about information to knowledge to decisions is important. That's where the soil test is information, it gives the advice, it can give some knowledge and then that's where the decision can be made based on that knowledge. So, I think that link is important having people who are experienced across a wide range of situations to look at that data and provide an interpretation and it's always good to have a second or third opinion about those things. So, use a couple of advisors, talk to the neighbor about what their soil test looked like and what they're going to do. So, I think there's running that information off across a few people is always good, but certainly having an accredited advisor is very important.
  • DREW RADFORD - Following this dry period, is the nitrogen and water which is further down going to be easily accessible for a crop?
  • ROB NORTON - I think that the key to understanding that is to know, again, a bit more about your soil. So, in a lot of the Mallee, there's a sub soil limitations, which are, can be sodicity, which is high levels of sodium. There can also be salinity and there can also be levels of boron in the sub soil that are toxic. The consequence of that is that even though we might measure a hundred kilograms of nitrogen in the top 60 centimeters, if the root zone stops at 30. Then the bottom half of that 60 centimeters is not accessible. So actually understanding your sub soil limitations helps you manage nitrogen, manage the crop, select the crop that's appropriate to the salinity or the sodicity or the boron levels and make an informed decision about the management of that part of the paddock.
  • DREW RADFORD - In nutrition programs, is there anything being missed?
  • ROB NORTON - Well, I think we, again, coming from our surveys, I think micronutrients need to be addressed particularly, we've always known in the Mallee that zincs important, on alkaline soils zinc is less available, there’s less there and that came home pretty solidly when I looked at the results from those soil tests that Dr Mason's been involved with and a large number of those come back with low zinc value, so thinking about using zinc supplemented fertilizers. Going in this year would be a good management's decision, but again, you can make that decision based on information which can come from a soil test.
  • DREW RADFORD - The core of what you do is agronomically focused. But I read a quote of yours a while ago, and it says, remember your family and community and those who you love. If you or those around you are struggling, seek help. Is this something that's becoming more and more present to you or obvious to you through the current dry times?
  • ROB NORTON - I think the problem with depression in farming communities and the farmers is a thing that's hardly talked about, but it's probably, of all the issues in agriculture, you know, farmer depression and suicides are not talked about and they should be talked about. Because farming is a human activity, it's a stressful activity and you know that you need to be supporting your neighbors and yourself, you need support. The reason you're there is your family, you know your family needs to support you and you know, old mate next door who you mightn't have seen for a couple of weeks. A whip over there and borrow something off him just to see how he's going or take something back that you borrowed three months ago. You know that that's the thing, just check on each other. I think country people are really good at that, but we get so busy. We assume things are right and they might not be, so it's your family and yourself that needs to be managed and looked after as much as your land.
  • DREW RADFORD - Rob, I'm also wondering, often blokes in particular are reluctant to go down that path, but there must be a very clear economic component to that. i.e., if you are in a dark place, that must make it difficult to make those rational economic decisions, so it almost becomes a business reality as well.
  • ROB NORTON - Oh, absolutely and when depression strikes, things aren't normal, things don't look normal and your ability to make rational decisions, your ability to and not necessarily economic decisions because not all farming decisions are purely economic and might be a social component to it. And sometimes, you know, you just need that need to reflect with others about what's happening and seek help, you know, the initials are, are you okay, that become important to just ask each other? Are you okay?
  • DREW RADFORD - I think that that's a fantastic message to leave this on Dr. Rob Norton, thank you for joining me in the Mallee Sustainable Farming studio today and all the best for the work ahead.
  • ROB NORTON - Thanks Drew, thank you.