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Learning from Cyclone Gabrielle recovery
(soft music) - Welcome to Cut the Crop, keeping you in the know about everything you grow. Researchers, growers, and other interesting folk delivering insights and information on topics ranging from agronomy to profitability, brought to you by the Foundation for Arable Research. - Hello and welcome. My name's Alison Stewart, and I'm your host of this session of Cut the Crop. And today we've got our senior environment researcher, Dirk Wallace with us, and Dirk is based up in Hamilton. So welcome Dirk. - Thanks Alison, great to be here, looking forward to chatting. - Yeah, so you were part of a study where the report has just been released on recovery of land covered by silk during cyclone Gabrielle. And so we wanted to just talk about what that project was all about and what came out of it. So just start off by telling us what actually did the study involve? - Yeah, it's a good question. So obviously in Chatsy, I'm wise back to February 2023 when cyclone Gabrielle came through, huge impact across the east coast of the North Island. The whole of the North Island was really impacted, but what we saw was a lot of damage on the east coast region. And so what we wanted to do was work with growers as they went through recovery because we knew, we essentially knew they'd be the experts in getting their land back into action. We wanted to work alongside them to document the decisions they made and how they were successful or not successful, depending on what kind of impacts they had from the cyclone. So the way to put it neatly is really we were trying to document hindsight. So future growers can pick up a book and kind of learn from the knowledge of folks in the past. - Yeah, and I mean, there was quite a variability, wasn't there in the amount of silk that was deposited? - Yeah, exactly, yeah. And beyond salt, we had growers that had almost whole forestry blocks turned up in their maize paddocks, for example, all sorts of things turned up that required a lot of effort to get out and get the ground back into a cropable state. So I guess for context, we had 46 sites across a range of regions on the east coast. Those were, they were based in clusters around the here-of-time plains in Hawkes Bay, central Hawkes Bay itself, also up into the wider lot. And then in Gisburn and also in Tologna Bay, we had groups of growers working with us there. So one of our messages when we were out to talk to folks was, well, one of the messages we got back was they weren't regionally relevant information. So that's why we tried to spread a study as far as we could. And across those sites, like you're asked about in the silk death range for a couple of inches to over a meter deep. So yeah, really quite dramatic differences. And so how did the growers and you guys, how did you decide what approaches you were going to try on the various different situations that occurred? - Yeah, that's a really good one. It was really up to the genius of the growers, to be honest, and it would depend on what options they had available to them. So some of them, I mean, we had growers out around Gisburn that they had essentially turned back into lakes. One of them, they had a result of a 60 year lake. So if that's your situation, then you don't have too many options. But if you've only got a small amount of sediment and a drain quickly, then a lot of them could get back into action as soon as time allowed, really. But it was kind of a case of a few things. The first one just being patient and waiting for the ground to be workable, and the next being kind of what machinery you had available and how easy the soil was to work. So yeah, it always depended on what options were available to the grower. - So what were the key findings? Because obviously, depending on how deep the soil is, mixing it in might work or it might not. - Yeah, that's a very good point. So I think that some of the key findings, really, were that when the soil came through and tended to not have a lot of air in it, it was quite a sealed down and compacted. And one of the key things to do was to get air back in that soil, to get the biology working and so allow plant roots to start growing. So I think it was a common kind of thread there that mixing the salt allowed better outcome. If that soil was quite shallow, then you could incorporate with the soil and that was quite an effective way to get a seed bed and get back into cropping. When you had soil, it was a meter deep. You don't really have that option. But I guess what we found was that regardless of the soil depth cropped right into a stablish and in some of the regions, we got yields that were comparable to other salted blocks, for example. So whereas other regions, the season wasn't quite so kind and yields were down across everywhere. So there's a kind of seasonal effect that impacted the outcomes of this local world as well and of the recovery. So I guess our usage would be around those forks bay based sites and a lot of the water, a lot of good crops were produced and water didn't start raining all season, really. So a lot of blocks just couldn't be replanted into and it just when it was very wet and they had a lot of NLP issues in the maize crane. So yields were down, I guess you could argue yields would have been down there a year anyway. So looking forward to seeing how they get on this season. - And was there one, were there any particular crops that were better to use as your first establishment crop? - That's a good question. I think the likes of maize and squash and things like that are a bit more resilient. Although we did get good yields out of peas, sweet corn and beetroot and orks bay. No one was game enough for the sites we followed to plant something like onions, but there is a bit of discussion about potentially going into onions or some of those blocks of land this season. So I think inherently growers kind of picked something that they thought would be pretty robust and that tended to work well. The only challenge we really had was on the sandy as well. So stuff that was a bit of all free draining and instances where you put in carrots and things like that. So processed carrots, which is quite a fine seed. They were getting issues with germination and soil establishment, all those kind of course sediments. So yeah, kind of going with a bigger seed and going into areas that were holding water and allowing germination worked quite well. But some of that's any stuff is a bit of a longer term challenge that the growers working with that are trying to build organic matter into those soils and kind of turn them back into a soil moving forward. So yes. So that was one, I guess my next question, were some of the soils not ready to be able to establish a crop in that first season and the growers decided that they would just incorporate organic matter to get them ready for the following season? Yeah, yeah. So in terms of approaches, I mean, some of them did manage to grow in early season, I guess, cover crops, to try to build that organic matter. And some of them just left it if it was too wet. So that would depend on the success of that, depending on the moisture of the sediment. So there was early on, I was messaging around flying seed on to establish crops, but the seed really needed to make contact at the right point. And then you get an amazing looking, amazing looking cover crop. If it didn't get all the right point, you got something quite patchy. So it was quite dependent on timing again. And then those really wet blocks, they didn't really, yeah, a lot of them just didn't drain in time for a sensible planting date. So some of the maze blocks weren't able to be planted until late December. And even then, it's just pushing it too far. So it's been a case of working with the sediment and working with the conditions. There's been a few examples of people trying to push it by trying to cultivate and very weird ground to get the force of water out in many ways. The learning there has been that that just ends up producing concrete and more of a headache and more diesel to spend. So, yeah, I think it's, I think we've got, yeah, with 46 different case studies in there, I think there's just about every decision you could make. So a lot of learnings really. Did any of the growers try and like remove the silt? You know, like just literally, you know, go in and try and remove the silt and get rid of it somewhere else? Yeah, yeah. So that was, that was a practice done particularly in pre-new water culture as well. Some of the cropping blocks did a tend to do that and actually planned for research, ran a trial looking at the effect of like a small plot trial looking at removing. The challenge was it wasn't really a yield increase of doing that. It cost a lot of money and often you ended up compounding the ground so much that the crops performed poorly or you needed extra ripping. So I guess the key thing was even if you had a meter of sediments on the ground, you could establish a profitable crop in the right conditions. Or just go, just leaving it here and going straight into it was an effective solution rather than worrying about the expense and headache of removing it all. But that's, yeah, that's one of the neat things we've learned here and you can only really learn that I, having people, are trying different things and recording their stories. So really grateful to the growers that working with us on this. So are there some situations where you're not, you're not expecting some areas of land to be able to come back to, you know, what it was, pre-cyclone and for at least three or four years? Or is it actually, you know, like one year in everything's back to normal? Yeah, it would be nice if it was one that it's a long term. They could keep it essentially. These growers are farming on the new ground now and they come up with new questions. I guess we've shown that in a good season, you can get a decent crop out. But we are also noticing that the growers' feedback is being that the ground is now different to work. So there is going to be challenges with this sediment type and the sort of being incorporated into their old soil. It's going to behave differently. There's a lot of fertility issues that are interesting and a lot of kind of add to pens and a lot of, a lot of guessing as to how to manage things moving forward. But the positive message is that, yeah, the majority of those fox vagaries were successful and the Brisbane growers largely still going to yield out of their blocks. So people moving forward with it and I think that's the nature of the beast, isn't it? You, things change and you've just got to adapt and keep moving forward and it's, yeah. I think that's where most folks are at. Yeah, I mean, lots of learnings around what to do when it happens. Are there, were there's anything that came out that could have been a proactive management strategy to minimize the impact if something like that did happen? Yeah, I think there was a lot of talk around drain clearing and maintaining waterways and all of that stuff. So I think that's, that's something this program hasn't really gotten into. But I should mention there was a lot of immediately following the cyclone. The government was very supportive of funding research projects that helped recovery. So there's been quite a few different bits and pieces of work put together and hopefully this project and all the others will kind of come together to put their learnings in that way we could kind of, you could turn to one manual essentially and say, yes, if you're, if you want to reduce the risk, then these are the steps you should take. And if it's still, if things still go wrong and you've got to recover from an event like this, then there's the steps you should take. So that's where I'm hoping it will get to. But I think there's probably as far as I could comment on that on Alison. Yeah, so you, I mean, we've completed this and there's obviously lots of other work that other people have done. So is all of that going to be pulled together into like a grower resource booklet? That's, that's what we're hoping we'll do. So we, so far as working with the other researchers essentially to work out what this could look like and how we can make pretty much enduring resource. So part of the challenge was when we were working with groups like, like land-wise and planted food and data research early on to understand how to recover the soils, they were finding, they were essentially finding bits of research from earlier floods and people's shoeboxes and the bandages and things like, you know, like very helpful when, when you're standing in three metres, wow, a metre of sediments in your, in your maize block. So that was one of the things we've all agreed on. We, we really want to pull it together and make it, make this information live somewhere centralised so that it's easier for future researchers and growers in your own house to get their hands on it when they need it. So yeah, definitely a key outcome Alison. So is there still work going on with those growers or is that the project finished? That one's, so that our project was funded by MPI and vegetable research and innovation and that project is finished. So now we're just starting to talk through what's the best value for growers as a, that we put it into centralising what's information after year one and then maybe go back every two years, catch up with them, see how things are responding and build the story that way or whether we continue to monitor every year is kind of long-term until we've got a really complete data set. So we, yeah, currently still talking through those options. And, yeah, can you still work with folks and talk to growers that are experiencing, you know, challenges on these kinds of soils because it might shift, we might shift more to some agronomy response type stuff that might be a value. If you know what I mean, we're getting challenges around fertility or leaf disease or something like that, due to sediment, then maybe we focus on that to get them out and run it. Excellent, okay. So any final messages or key take-home messages from this work that you want to just repeat? I have to thank everyone that was involved. I mean, this was a program that involved a lot of people. First and foremost, it was the growers because they were the ones taking the risks and applying their expert knowledge. We actually took them back, seeing them learn from them. And then secondly, I'd say a huge thanks to the contractors we worked with. So we worked with Alan Kayle and Diana Mathers and Hooke State and Elliot Calder and Melanie Brite up in Giswin. And it was really neat having folks that had really good connections to all the growers around those regions. So that was really nice, and I think that's why we got a good outcome. But the key, the really key stuff was that people needed to look after themselves, first and foremost, you know, and then take their time and their recovery efforts, you know, slowing down and giving some thought as to whether you should get out and get on the ground. You know, saves you mental health, that also saves you your diesel account as well. And then, yeah, just continually moving forward is the other thing we've learned from them as though. You can't really look back, you've got to keep moving forward. And hopefully this reasonable sort of give future growers something to look at and give them some understanding of, yes, we've been here before. This is how these other people go through it and pick up some notes and make their process a little bit more supported and a little bit save them a little bit of time. That's the hope anyway. Excellent. Good. Thanks very much, Dirk, and we'll await the sort of compiled report. And hopefully some time that will come out. I mean, what's the timeframe do you think for being able to make that report available to people? Yeah, I think it should be done by the end of this calendar year. So it should be available for Christmas or summertime reading for anyone. And moving forward, hoping to get something, I'm talking to some of the other researchers and hoping to get an event or something like that to pull this information together, hopefully in the new year. That's a priority, I think, for all of us. There's real good world there and we're all keen to collaborate and get more information to get it for growers. So that one's too wait and see, but... Yeah, excellent. Great. Thanks very much, Dirk. And thank you very much, listeners. Have a great day on the farm. Thanks for tuning in to Cut the Crop, presented to you by far. If you'd like to know more about any of the topics discussed or have any suggestions for future topics, go to dub dub dub dot cut the crop dot co dot E&Z. (gentle music)