Al and Juddy are back to let us know about the wonder plant that is white clover: how important it is to farmers in New Zealand, the different types and how they are best utilised, its role in nitrogen fixation and the benefits to our animals. All of this as well as a bit of an introduction about themselves and how they came to be sitting in front of a microphone.
"The more clover you can get in there, the higher the performance of those animals."
Juddy Welcome from your tractor or your ute. Maybe you're even driving an electric motorbike, but welcome in. You're with Allister Moorhead and Glenn Judson and this is the Al and Juddy Show. So what's in it for you guys? Well, what we want to do is reach out to you and provide some information in a very different way in terms of many different topics which are going to influence you. And we want to do that in a way that allows you to listen to it when you want to listen to it, where you want to listen to it, but still get that excellent information. In this particular episode Allister, what are we going to hear about?
Al Well, thanks, Glenn. What we're going to be talking about and covering are reasons why white clover is important to the New Zealand agricultural system, types of white clover and how they are used, the role of nitrogen fixation moving forward, the different impacts it has on animals and probably covering off the different types of white clovers that we have available today, look at a few of the pests and probably conclude with just a few of the take-home messages that we're going to cover.
Juddy Al just give me a bit of background on you. How long have you been in this industry and what do you actually do as a job?
Al Well, Juddy, I think it's probably wise to start at the beginning, actually, because that probably gives a few people a bit of an idea of where it all comes from. I started uni at Lincoln College in 1989 and I happened to meet one Glenn Judson doing an Ag Sci at the same time. So we started at Lincoln College in 89, doing a Bachelor of Agricultural Science at the time. And pretty early on in the piece, we both identified each other as kindred spirits for no other reason than that we have a pretty warped sense of humour and both of us are pretty competitive. So we did a lot of training together, even though I played hockey and Juddy played rugby, so that's pretty much how that started. We got through our degrees and I started a master's in Ag Sci in about 93 ish, I think. And unless I'm mistaken, Juddy, did you start your Ph.D. straight away or did you start working?
Juddy A year after you. You were ahead of me. And it's probably good to point out that you were very much focussed on the plant science side of things, which was really only a solution to what I was studying, which was the animal side of things. So we do come from a slightly different viewpoint.
Al We did have a couple of crossover moments, though we had a bleed sheep and did copper samples on stags and things like that. So it wasn't all just the plant based stuff, but we did separate into plants and animals at uni and then I did a master's in Ag Sci, which took two and a half years. I might have played a bit of pool at the time to stretch that out a little bit, but I then started to wait for my colleague to finish his Ph.D. before I graduated, and so it might have taken another five years for me to graduate after I started work waiting for a certain Glenn Judson to finish his PhD. And I started in the commercial sector straight out of uni in 2005 for a company called Hoddy and Tolley, travelled around the South Island as a Territory Manager. Pretty much you’d describe it as a sales agronomist and I did the whole of the South Island. That was a pretty extensive job and probably started that pathway of seeing a lot of environments, a lot of landscapes travelling from the south coast of Invercargill to Golden Bay and all the areas in between. So it was a really amazing way to start a career to see that far. It was a very intense job at the time, travelling that sort of distance, though. So yeah, that's how I kicked off.
Juddy And you will have seen a lot of different farm systems as well as environments, everything from...
Al A lot of farm change. Yeah, a lot of farm change through the 90s, particularly, you know, I was pretty much watching Southland convert out of sheep into dairy in the first wave of conversions in the mid 90s and then obviously, likewise the second in the early 2000s. People tend to forget how tough the sheep environment was in the 2000s and how that became a natural path to the dairy conversion in Southland in that age. So we saw a lot of that happening and changing. And so watching land use change was a big part of the start of my career. And then I went on into PGG Seeds, where I worked there for about six to seven years before we crossed paths again and we'll come back to that interaction. And then I moved to the merged entity of PGG Wrightson Seeds and the brand Agricom was the natural process of the merger of Agricom a company founded out of Ashburton and the PGG Seeds business and I've been in the business now for about 25 years now. Yeah, your path...
Juddy Well, actually while my good friend Allister Moorhead was doing his master's, I was at then it was Lincoln University it changed to. And I started a PHD there looking actually at deer production, looking at how Red Deer and the Wapiti cross differed in terms of the productivity out of a farm system. So after completing that, I then went to a group in South Canterbury called Deer Master and they were a group of farmers who were collecting a whole lot of on farm information. And they needed someone to make some sense of that information and produce some written material in terms of how you could improve productivity on deer farms. And one of the projects that we ran was the requirement of trying to generate some lactation feed in what was then quite a dry east coast environment. So I turned to my very good friend in PGG Seeds at the time, Allister Moorhead, and said can you find me a solution to this animal quandary? We've got lactating hinds and we've got no feed and how are we going to generate that? So I guess that's sort of how we came back together and worked on that particular programme very successfully actually. We were able to generate some massive differences using some summer cropping relative to the resident brown grass that we were dealing with. So since then joined PGG Seeds in the capacity of an animal nutritionist and then have moved as there have been mergers over time into what now is the Agricom business. And very much look at the provision of crops seen in grazing pastures from an animal point of view. So that's kind of where I kind of fit into the business.
Al And to be fair, it's been a really productive and stimulating sort of relationship because we have come at very similar topics from two very different areas. And that's actually probably where the magic probably has occurred in our careers from that perspective. In that time, both of us have travelled a lot. We haven't travelled as much together as I'd have liked, but all through the eastern seaboard of Australia, I've been to South America for a number of trips. You've done your time?
Juddy Yeah, I've done Australia as well, but then into Europe and particularly in Ireland, looking at some of the differences that they faced in Ireland relative to New Zealand from both an agronomic point of view, but also an animal systems point of view. So we've got that experience in terms of a lot of diverse farming systems, if you like. Yeah, and the impact of foragers on that. Which brings me to the subject for the day, which is essentially on white clover. But it's in the context of the fact that under our new nitrogen limits, we are going to have to still be productive. And I guess that there's an opportunity here to look at white clover and what that might bring to, you know, this set of challenges. What is white clover Al? Can you give me a broad brush background of what white clover is?
Al Well, Glenn the thing about white clover is it’s trifolium repens. So that's white clover. But what it actually is for us, is it's a temperate legume that fits extremely well into our landscape, particularly one that is fertilised and as I described predominantly in a temperate landscape. It is a clover that is naturally found in grazing systems, and it's typically followed animals all around the globe. It's one of those plants that moves in those sort of landscapes, in those climatic zones and colonises grass landscapes where there is fertility, moisture and not too hot and not too dry. So that's white clover and it has found a very special place in New Zealand. We're one of the biggest users of white clover in the world, particularly in grazing systems, and it has a very strong fit. It would be described pretty much as our secret efficiency that you tend to find from the New Zealand farming system, is utilising the special powers of white clover in our day jobs if you'd like to say.
Juddy So when we talk about white clover and adding it to a mix, what are the common reasons that a farmer would site in terms of putting white clover into a mix?
Al Well, in the past, I would have given three, predominantly three to four reasons, and the reasons would for me personally sit in this order in the past: the first reason is that animal performance is optimised if not maximised by having a good content of white clover in pasture and the literature on the impacts of white clover on liveweight gain and milk production is quite conclusive across decades of research...
Juddy And we will touch on that later when we talk about animal performance.
Al Yes, I put that as number one, though, Juddy. That's the point is that why would you use white clover in a pasture? Because it makes a difference to animals performance both young animals, older animals and lactating animals. So white clover is special from an animal production perspective. The second reason relates to both pasture management and obviously animal productivity. But having white clover present in pasture improves the average farmer's ability to manage residuals in an effective way and it improves palatability and it improves the ability of animals to graze and hit your target residuals without you having to exercise other management. So if you get a critical amount of white clover in your pasture, the whole grazing management of that pasture is so much easier.
Juddy So probably, maybe less likely to have to top because you've got some white clover there and you've got good grazing management. Excellent.
Al And the third reason was very much because white clover has a relationship with a bacteria called rhizobia, which is capable of fixing atmospheric nitrogen and providing white clover with that and in doing that, it actually feeds the system both through the animal and the soil with literally atmospheric nitrogen or free nitrogen. So that is a pretty powerful mechanism for the plant to excel in a grassland where grass is hungry for nitrogen and the landscape is hungry for nitrogen and I'm a plant that comes with my whole packed lunch full of nitrogen. So that gives white clover a universal advantage in low nitrogen environments.
Juddy And you said that's third, but I guess in some of the environments that we're seeing - regulatory environments we're seeing - that that priority is coming up the order.
Al Well, I think it's been turned on its head. We're looking at a different set of circumstances now where our farming communities have been reviewed on and external influences are obviously having drivers on the fact that we need as a country to stay productive because that's attractive to the country and our farming community does an awesome effort at making our country a productive environment for producing outstanding nutritional products. But the reality is that is coming with a lot more scrutiny on the way we're achieving that and elevated inputs are not necessarily the flavour of the environment we're in at the moment. So what I did point out at the start is a couple of key drivers to the start of this conversation is that very much when you're looking at clover, it is still a medium to high fertility plant, so it needs a base level of fertility to actually perform. But when it's in a healthy and growing state, it's capable of fixing a really significant amount of nitrogen for free, as we've just discussed. And that's what's making the difference at the moment as our natural nitrogen levels drop in the landscape, white clover is able to get all the advantages and slowly get stronger and stronger and fill in some of the gaps to the productivity we're losing for the reduction of nitrogen in our landscape.
Juddy In terms of different types, are there different types of white clover? And in saying that talk about a little bit about where you might use those.
Al Well, first things first, white clover is trifolium repens, so it's all white clover. But in the broader and more general sense, yes, there are different types.
Juddy Can I just jump in? Have you heard about the new clover that only grows on Saturdays and Sundays?
Al No Juddy, I haven't heard of the new clover...
Juddy It's called trifolium weekends.
Al Ha! Sorry that is just shocking. So we'll put that one to bed and move on. So yes, there are. There are different styles of clover and white clover, and historically and I think today it's still currently appropriate that they can be banded into three broad categories, and you tend to have what is described as a small to medium leaf size and that reflects plants that are ecotypes from more intensively grazed environments. And you tend to find leaf size tends to get smaller and smaller with more and more intensive grazing.
Juddy And that's probably because that plant's trying to avoid grazing by smaller leaves and getting closer to the ground.
Al Correct. And it ends up with more light and more space, and is getting pinned to the ground and so can't express itself to its full potential all the time. The next description would be a sort of like a medium to large leaf size, and these are starting to get quite big. And I think the word that you're probably going to come out with is that they have a lot of plasticity. They can be pinned down and they can be a lot more closer to a medium leaf size under drier conditions, less fertile conditions with more intensive grazing. But given a longer rotation with a bit of moisture and a bit of fertility, they can actually get really quite large. So the medium large types tend to be the most plastic, and they do move from being medium to large, depending on the environment they're in. And then you get the large leaf types, and these types tend to excel where fertility is high, moisture is consistent, warm environments and you tend to find these compete with vigorous grass strongly. They are quite upright, they're quite large, and they really fight for their space in pasture that is really productive. So the large leaf types are very impressive. They can get to the size of the palm of your hand quite successfully. And those three categories are also quite closely linked to stolon density. You tend to find the finest stolons in diameter with the most branches and the most spreading across the ground are found in the medium, small to medium types, and as you get bigger and bigger in leaf size, you tend to find the diameter of the stolons, get bigger and bigger and fewer and fewer. So there's a relationship between stolon size, shape and density and leaf size.
Juddy So if you are in a sheep production system, for example, and this was feed for ewes, for example, you might drift to the smaller leaf size and try to get some persistency out of that. If you're in a finishing system, maybe with deer or cattle, you might be drifting to the higher leaf in terms of the farming systems.
Al That's exactly right, and you tend to find the one in the middle sits inside that mixture as well on either way.
Juddy That can move depending on the environment. So we've talked a lot about this nitrogen fixing, and it's becoming really important because it is becoming a really important source of nitrogen, given some of the limits that we're under. Let's talk a little bit, you know, what we're breathing in here is about 78 percent nitrogen and the nitrogen is fixing it. Can you give us a bit of a high level description of what their fixation actually is?
Al The clover is fixing it you mean?
Juddy Yeah, so give me just a layperson's description of that.
Al Yeah. So there is definitely some literature and equations that highlight that for every kilogram of drymatter a clover plant produces, you're getting about 28 grams of nitrogen fixed that is going through the plant and is accessible to the animal. So the 28 to 30 grams of fixed nitrogen is again cycling in the green leaves of clover, going, passing through the animal, being partitioned into meat or milk and then being urinated mostly urinated out onto the pasture. And that is the cycling created by the animal. There's about a similar amount that's occurring with the breakdown of roots, particularly the fine root hairs, the nodules that sit on the fine root hairs, they break down predominantly in the winter and the summer, and when they mineralise on the rising soil temperatures, when the microbial life starts to kick off in the warmer times of the spring and the autumn, they are strongly responsible for the big spike you get an early spring growth. And likewise, the little spikes you get in autumn growth as you come out of the dry, you hit some rainfall, you got mushroom season and you tend to find that little punch of growth. You get into April nationally is the breaking down of summer root mass, and that's been converted into a more available nutrient. So the big point is the stuff that's breaking down in the roots isn't coming at you at a uniform amount, at the same rate every day of every part of the year. They're predominantly feeding the spring flush and predominantly feeding the autumn flush.
Juddy And I guess and the nitrogen that's coming through the cycling of the animal that is coming on a relatively regular basis. But the problem is spatially, it's not and we're creating urine patches in those urine patches are actually an important source of nitrogen loss from the system through leaching...
Al Through overloading.
Juddy ...Is through overloading. So these two different ways of cycling nitrogen one's through the animal one's through the plant and they and they are actually working at different times and in different ways.
Al You know, just for people to visualise in this case of dairy cows, which is highly topical, how much of the landscape or a paddock does, you know, urinary nitrogen actually cover in a calendar year?
Juddy It's really interesting that some of the grass pastures can be around the 25 percent mark.
Al So that's of a per hectare...
Juddy ...basis. But it's really interesting in some of the mitigation options we've got in terms of Ecotain®, for example, we've managed to increase that because we've increased urine volume, and so we have more urinations per day, and that means that its spread slightly more. We are getting some overlaps as well. But that certainly helps in terms of the area that we're covering. So if you think about it in a year, you've got a hectare, about a quarter of that will be covered by urine patches over the number of grazing.
Al And I suppose talking about taking the piss and the role of urine in this case, the reality is this is what we still have to deal with as an industry. It's not perfect. So the cycling through the animal: one, it causes our problems but the second thing is that it's very spacial and farmers have always dealt with this and that's why subdivisions played such a big role in the spatial distribution of, for example, phosphate out of dung, particularly. But the same can be said for, you know, in the ideal world, you'd ask all the animals just to spread it around uniformly. But it actually comes in patches and the point is it's not the whole paddock. It is literally only empowering between 25 and what is it, 30 per cent?
Juddy Yeah, yeah. So I guess if we're talking about the animals in terms of performance, you mentioned earlier that there's a really good correlation between the amount of clover in a pasture and an animal form. So I want to tease a little bit more of that out because for quite some time, we've known that it's almost a straight line relationship. The more clover you can get in there, the higher the performance of those animals. And so we are driving for higher clover contents, we are expecting higher performance out of those animals. And there's a couple of reasons why that actually happens. So first of all, we're talking a little bit about intake related issues here and in the fact that clovers tend to be the harvest dynamics, or the ease at which these animals consume it, is higher for clover, and that's because they've got leaves that are in the horizontal plane rather than grass which are more in the vertical plane and those are more easily harvested. Every mouthful, you've got more material going down the throat, every bite, and therefore in a day they graze more. So it's much easier. And I've done some grazing demonstrations where we have got down on our hands and knees and with our thumb and forefinger, we've pretended to graze and certainly pastures with high clover content are easier to get more in your shopping bag, which is what we call the rumen than those that have very ryegrass dominant. So, and even more so for some of the herbs and brassicas, for example.
Al Would you describe that as grazeability?
Juddy Yeah. Grazeability, harvesting dynamics, how easy is it for the animals to get intake.
Al I think we used to talk about it a lot. These are all about factors affecting intake. So the way you present pasture is one thing, but what the pasture is made up of has a big impact.
Juddy Absolutely. So that's first thing. The second thing, and it's something it's not quite nearly as obvious, but it has quite a big impact here is actually how long it takes for that material to pass out of the animal. So the passage rate.
Al Yeah. Fractional degradation rate.
Juddy So the speed at which material that these animals are consuming breaks down to a particle size that's allowed to leave the rumen, distinguishes how quickly those animals will return to grazing. Fast passage rates, fast breakdown speeds will mean that those animals will return to grazing sooner because the rumen has emptied out. And so having clover as a proportion of the diet, a fast degradation rate in those animals will actually eat more in a day. And you see that in a lot of the work that's coming through, particularly around Ecotain, for example, is you see that intake creeps up, the more they're putting all the feed in front of them so they don't have to harvest it, but they're eating more simply because that passage rate is much faster.
Al One of the things about bringing more nitrogen into the plant means that our levels of crude protein are more consistently high, which is part of the secret of white clover. So you've mentioned the fractional degradation rate, the horizontal leaves from a harvest dynamic perspective, but just tease out the whole efficiency of a protein found in clover versus grasses and other species.
Juddy So the way that nitrogen is stored in a clover is quite different to some of our other species. And I guess that you know, at opposite ends of the spectrum, we've got a clover that's fixing its own and we have a lot of true protein so that's actually processed quite differently in the animal compared to what we describe as non-protein nitrogen. So that's all the other nitrogen compounds that we call crude protein, but actually are very quickly mobilised in the rumen and a lot of that ends up in urine. So these very quickly mobilised nitrogen compounds are sometimes lost to the system in urine. So actually having plants with true protein because there's a breakdown step in the rumen, and a lot of those actually escaped the rumen and are absorbed further down the gut, so therefore we get a much higher uptake of protein. And where we're dealing with true protein rather than these non-protein nitrogen compounds, so we actually get an increase in terms of the protein that the animal was able to use from things like white clover.
Al So the thing about this is that clover seems, obviously we want it and I'll go back into its place in our production system as we expand this out. But it sounds almost too good to be true. And when you tease out these things there's always fishhooks. And so the one thing I would sort of dwell on particularly with cattle, is that what are the sort of animal health issues that exist with white clover, particularly?
Juddy So we've got this faster passage rate, we've got animals eating more, but we've also got we sort of get to the edge of having animals that are growing very fast and then we run into some of these issues. And the first one, the most obvious one is bloat, and that's where we've got this stable foam that forms in the rumen and it stops the animal, releasing gas through burping and a lot of it is methane. And so we get the reduction in terms of being able to get rid of that gas essentially we blow up like a balloon. And so bloat is a real issue. And it's certainly it's sometimes there more prevalent and worse and so pastures with higher clover content are a danger at that time. The other thing is, sometimes when we get climatic conditions, we've got moisture and we've got cattle that may be hungry and eating lots very quickly or where intake is actually going up and down quite a bit, it's changing over time is where we start running into issues with bloat. Now it doesn't mean to say that we shouldn't have pastures with lots of clover in them, what we need to be mindful of is at those times that we need to be able to mitigate some of those risks and the use of bloat oils, making sure that we've got animals that are well feed, you know, keeping an eye on these animals and looking for issues.
Juddy Yep. So again, the double edge with fibre, I guess, is that you're wanting these animals to eat lots and be very productive but then you've sort of gone a little bit far.
Al Well, fibre sits at the other end of the frictional degradation rate, doesn't it? Because fundamentally, it just fills the gut and sits there...
Juddy Slows everything down...
Al And stops animals eating other things. And on average, most of our fibres are very low quality relative to a green pasture plant.
Juddy The other thing that fibre does actually is increases the amount of chewing the animal does, and that's releasing saliva and saliva is a particularly good buffer. So that can be very useful when we've got issues of subclinical acidosis, for example. So, we can fix this.
Al This is not just a problem with white clover, just that it's been associated with legumes. So just I will ask the question is there more than one form of bloat?
Juddy Yes there is, so you've got what we call the frothy bloat or the foam forming bloat, but we've also got what's termed feedlot bloat, which is essentially the fact that these gases aren't being expelled out of the rumen because we've got an acid environment. And so there are two different things here, clover is normally associated with a frothy bloat. And as you rightly say, it tends to be clover, but it can be all legumes. We've even seen bloat on Italian ryegrass, for example, in that really fast growing...
Al middle of spring and possibly the end of autumn.
Juddy If we are trying to stretch the amount of clover we've got in our pasture, how would we set that up?
Al Yeah, I think the key really is there's a couple of low hanging fruit here, and on the scale of it, it's about competition. It's getting your fertility regime right and it's then about your establishment phase. And so typically, the way we make our average pasture mix is about creating a mixture that can perform, establish, perform and meet a person's expectations ninety-five per cent of the time. We in the industry don't necessarily want to have to hold every single paddock's hand whether it gets going or not. But so typically, we're using strong rates of ryegrass and strong rates of white clover as our primary drivers. But the conflict in a normal pasture mix comes at your sowing time and the way you manage it through your first couple of grazings. So with sowing, it's all about sowing depth. And the reality is that we lose a lot of our efficiency of the amount of seed we put in the ground the deeper we go with clover, and it's quite dramatic once you hit below about one and a half centimetres. But as you approach two to two and a half centimetres, you are only getting a fraction of the clover that you would be delivering into your pasture mix. So the happy place and the sweet spot sits at around one centimetre to almost the surface with white clover. It is actually one of the few plants that really excels by germinating on the surface as well. So strategies of sowing half your clover at about a centimetre to a centimetre half or to broadcast on the surface the second half of the clover mix are really valid, but you've always got to keep in the back of your mind it still needs space. So this is where you come in and I'm still sticking with a standard pasture mix and what that space is created for. How the space is created initially is by how you handle your first grazing round. So the traditional technique for monitoring a pasture for when you can first do your first grazing is the pull test, where you take your thumb and forefinger like you said before and you go down your rows. And as long as you're not pulling out your plants as you're going, they're often in a state ready to be grazed. So the key here is about a farmer's approach to how he manages and utilises his young pasture. If I take the autumn-sown East Coast dryland mentality, my autumn sow of perennial pasture is quite often valuable winter feed. So I carry that forward as a perennial pasture to quite a high cover because I'm actually using that as winter feed. Now that's quite the opposite to establishing excellent clover, where really you're trying to keep the light coming into the base of that pasture. You're trying to keep light hitting the ground and around the clover growing points because that helps them create their stolons, their runners, and from that you keep getting the spread of the white clover into all the gaps in your pastures. Basically in the first six months, shade is your enemy to establishing good clover stands, so you can see there's a conflict regularly between a farmer wanting cover, wanting to transfer young pasture forward in a finishing role or a wintering roll because of vigorous young pastures and because they allow them to build up, they create shade. And when they create shade they're putting pressure on clover and the clover's ability to run and find space so that's a normal pasture. Recommendations sit around sowing depth, being shallow sowing with some seed possibly being spread on the ground, grazing to allow light into the pasture on a regular basis would be my two big drivers of keeping clover in a normal pasture. But if you came to me and said, how do I always get good clover in my pasture? I would then start to come down and break down your individual paddock circumstances and more than likely start reducing the grass content of your pastures. Probably keep your clover content the same, but try to mitigate the big shading events by putting less grass in. So that should send a signal to you that what I'm doing though, is I'm taking early dry matter away from your system to artificially give that clover a chance to get ahead of the grass or keep up with the grass.
Juddy So in a farm system if you were after finishing feed at the other end of the year, actually you're best to graze those early, keep the clover content there because actually drymatter is not what you're after...
Al …not a big deal. Correct.
Juddy The other thing was going to say and this might explain why, sometimes we hear about the fact that nitrogen kills clover, and I think some of that some of the...
Al Nitrogen doesn't kill clover.
Juddy Some of the comments you made there were really, really interesting in terms of why when we put on lots of nitrogen, don't we get lots of clover if it's not killing it?
Al Well, first things first it may not kill it, but it makes it lazy. So that relationship with the bacteria and the nodulation and the conversion of free nitrogen from the atmosphere does decline because as a plant, it works independently of its symbiotic relationship with rhizobia and it will actively seek free nitrogen out of the soil to grow itself. So it doesn't just rely on the rhizobia relationship. That's it's special power for a low nitrogen environment. But if you're feeding, you're starting to make the rhizobia lazy and white clover will start seeking itself. However, your point is more around the grass we put nitrogen on to boost feed when our farm system actually needs it. And the key to that is that's how you use that feed that defines whether you can keep clover there. If you're building up two thousand eight hundred to three thousand covers, remember what I said, the trigger for white clover success is light. So if you're doing that on a regular basis, you're creating a lot of shading. Residuals also have a big impact on that. So you put nitrogen on, you grow some feed. But if you're maintaining residuals that are creating thatches in your pasture or building up mass in your pasture, the reality is you're not getting light into the rows or to the base. So that's that conflict. It's not that nitrogen kills clover it's your management of your extra growth that kills clover.
Juddy Yeah, yeah, no, great point. Because I think it means that they're not mutually exclusive. You use small amounts of nitrogen and benefit your whole pasture.
Al I think what gets lost in the conversation, Juddy, is that the beauty of applied nitrogen is that its uniform. You define the rate that it goes on, and all plants need nitrogen to be nutritionally in a happy place. It's a macronutrient of importance for plants that includes clover, all grass species and so uniformly fed pastures are healthy pastures. So, you know, people get selective about what is healthy and natural nitrogen cycles are healthy for the clover. The grass doesn't get it in a uniform way we have to remember, but the point still being is well feed, strategically feed and not overfed pastures are very nutritionally healthy.
Juddy Pests. We've talked about the clover and we actually talked about the grazing animal, which must be the greatest pest, but we make money out of this. What are the other common pests that we've got? That we need to be looking out for white clover?
Al Well, white clover has got a few, but in recent times it's been quite a dramatic pest that entered the country sometime in the nineties and it's clover root weevil. It probably sat around the Bay of Plenty initially, I was part of the early phase of the education of the emergence of this pest. Like all biological introductions, you tend to find they hit critical masses and then they sort of move out in waves. And we don't even, I don't know whether anyone can pinpoint exactly how long it was in the Bay of Plenty before it started moving. But it is a pest that arrived in the country without any natural predators, and it is the adult that creates notches in the clover leaves and its larva chews off all the roots hairs and nodules off the roots. And so if the larva is continually taking the roots off the white clover plant, which doesn't have big, big fibrous root structures, it has fibrous root structures but they are not what I describe as extensive. And those larvae are really stripping those roots off. Soon as you hit a summer condition and as you get overgrazing, the plants are being yanked out of the ground or they losing all their water use efficiency and they're just shrivelling up and dying. Because remember, white clover does like moisture, and if it's got no roots and it goes dry, it doesn't have moisture. So clover root weevil, virtually every farmer, everyone listening who farms will have experienced it. It has ripped through the whole of the country, over a period of about 15 years, from north to south, travelled on cows and moved south in big leaps after it started moving out of the Bay of Plenty into the Waikato. So this pest of white clover is definitive, without its natural predators in this case, we've brought in a parasitic wasp that's been pretty successful in moderating its populations, but it was capable of destroying pastures.
Juddy Do you know where the little wasp came from?
Al Oh, I don't know, but I'm suspicious this one came from Ireland.
Juddy It did. It was out of Ireland. So it's done a good job coming all that way.
Al and they don't have problems in Ireland. It might be because of the whole family of pests and parasites there. So yeah, no, that's probably the big one. But when it comes to things like establishment of white clover, direct drilling, which is very much seen as an environmentally useful establishment technique today, slugs are by far one of our biggest enemies of establishing white clover and even fully established white clover slugs can do a real job on them. Other bugs: grass grub, I remember live weight gain work on grass grub larvae and white clover grows wonderful larvae. Their live weight gain on white clover is exceptional, so, you know, grass grub really target white clover roots. Porina is quite effective at eating white clover as well, so it's got a myriad of pests that do interact with it. None of them are as damaging as the clover root weevil, grass grub probably would sit at the next. We have clover flea in different parts of the country, which is a bit destructive at times, and cosmetically damaging as well. So the point is there is a myriad of things. So we need to keep the environment in the favour of the white clover, more often with good phosphate levels, good PHs.
Juddy At sowing can you protect against some of these?
Al Seed coatings? There are definitely seed coatings that protect against some of them, without a doubt. But natural bio controls are some of the big ones. Nothing protects against grass grub. Porina and the clover root weevil has been sorted out by the parasitoid to a fair degree.
Juddy And these will be, you know, some years they're bad. Other years are not so bad. Some regions are worse. So yeah.
Al The clover weevil being the biggie is as this is the key is it's a natural biological control, the parasitoid. So the reality is in any different year that the pest can get ahead of the parasitoid. So every now and then, even though it's well controlled throughout the country now, you can see whole paddocks being wiped out before the parasitoid catches up. So if you get a cold winter, for example, the wasp population may be behind and as the weevil gets ahead in its population and strips out all the clover, the parasitoid's building its population behind it. So that's the thing about bio control, they're never at the front of the population they're always growing behind it. So every now and then we'll get these storms and unfortunately, many of you will experience exactly that and you'll lose paddocks of clover. I give it 12 months, and many of them will recycle back with seed loadings starting to re-establish, but it's always worth over sowing to try and kick that off.
Juddy Listen, we're almost out of time. I've just got to run and shift some sheep. But I thought just before we go, we should actually just cover off what the Agricom white clover cultivars are. When I go down to my seed shop, I want to be able to ask, you know, for my cultivars in a bit of a knowledgeable way. So maybe what we should do is go through them and then sort of highlight which sort of farming systems they would be useful for?
Al Well, we've got a... it's pretty cool. My job is product development. So in a way, these are my babies and so with the breeders we sit there and review everything they create with time. And my job really at the end of the day is to pick the varieties that are the best fit for New Zealand farm systems, in my opinion, supported by the data of the breeding team and the evaluation teams. And we have an extensive evaluation programme from Kirikiri all the way through the country under both sheep and beef and dairy. So we do review a lot of information, probably looking at the medium to small at this stage, we've got a really nice product in Nomad white clover, it's probably sitting on the small side of medium. It's for me personally, it's for anyone who grazes set stocks in spring that they can chase a golf ball across the majority of the property for about a month, Nomad is the clover for you. And if you're forced into set stocking due to climatic conditions or it's just part of your farming process and you are regularly finding your golf balls in paddocks, Nomad is the clover that should be the basis of your white clover selection. But we have two powerhouses emerging that are always good add ons to a mixture where you might have Nomad as the base for that, but Tribute is New Zealand's largest selling white clover for the medium to large. It's because it goes pretty much in all mixes. It's capable of going to sheep country and dairy. We're in the phase of slowly moving towards replacing that, and to get that right, we've had to look for something pretty special and Attribute is a new generation of medium to large leaf white clover that is emerging in 2022. So we're pretty excited about its imminent release. Moving into the large category, which is where we'd describe them as the glory boys of the white clover world, because they are the big, big, big leaves and you always go, wow when you see them in action. But Mainstay is pretty much our large leaf white clover that's excelled in dairy country, particularly in summer dry dairy environments. And its recovery in autumn has always been very, very impressive. We are cycling that into the end of its life cycle and bringing out a product that is nothing but impressive. It's called Brace and very much has even slightly larger in leaf size and pretty much looking forward to that coming into our portfolio too. Really focussed on things like cool season growth, now that doesn't sound right when you grow a majority of your feed in spring and summer with legumes. I didn't mention earlier, but you know, the key to legumes is they only grow at about 20 degrees air temperature, and it's at that point they start to compete with grass. Many of our grasses are growing at around 18 degrees, so they have long periods of the calendar year where grasses have a stronger fit for growth than clover. But when it gets warm, the clovers really explode, and once you get those air temperatures, the leaf sizes really express themselves. And soon as you hit your 20 degree days, something like Brace is just going to be impressive.
Juddy And so you'd put it in a finishing mix or a dairy mix?
Al Yeah, anything from rotational high fertility, rotational graze finishing mix through to a dairy. And as I say, when you're in your finishing worlds, you're crossing over between rotational grazing and sheep and beef and lamb finishing, you know, Attribute is going to be the core of your decision and then you're going down to Nomad if you're slightly drier or you're slightly tougher on your grazing residues or you're going up to Brace and Mainstay if you're heading into the dairy and beef environment.
Juddy Do you ever mix those?
Al Well, that's what I'm just describing. You do, there's a cross over all the way.
Juddy But you could put two or maybe even three different clovers in a mix to try and take advantage of changes in the environment?
Al Look, I'll be the first to tell you now that some our breeders are extremely confident that you can actually make up a mix by just picking the right leaf size for your farm's particular system of that landscape. The other attitude to it, and I agree with that to, you know, to support the breeders and what they have achieved. These clovers are outstanding. And the reality is they can stand by themselves. They don't need to be in a mixture to be exceptional if you get your location right. However, the concept of mixing leaf sizes, remember what you described earlier is about these horizontal leaf plains? So white clover has got horizontal leaves and the concept of mixing is about stacking horizontal leaves at different heights, which is giving you a bit more bulk density through your pasture mass. It's not one plane and so you tend to see that rotates throughout the calendar year and you can sort of see there becomes a bit of depth to your clover production when you've got the different leaf sizes.
Juddy And I think the other thing there is that we're not just using our pastures, we're not just using them for one thing. And so therefore, sometimes we do set stock them and other times we are absolutely looking for a finishing feed. So actually having some of those different clovers in there kind of caters for those different jobs that our forages are doing.
Juddy Excellent. Well I think we've run out of time. It's been a fascinating wander through the subject of white clover. I think there's much more to it than, you know, some people think about, you know, like, it's a white clover and that's it. But there are lots of facets to white clover and I think the point that you made earlier about the fact that given the new environment, the fact that we are now farming under some nitrogen caps, the white clover is actually becoming one of the solutions to that. And as it's going to be more and more valuable, I think, is as we move into these challenges.
Al Well, I would say just to finish that is that we are already leaders in the use of white clover in the country. And this is this thing about retelling of stories. We are a world leader in grazing pastures full of white clover. What I probably would like to finish on is that we've taken it to a new level where our future production is almost dependent on its success because it offers that much to our farm systems. So I would see it as a nice way to conclude, Juddy, is that, you know, really getting our white clover right moving forward is a major part of maintaining the productivity in our farming landscape we enjoy today.
Juddy Thanks, Allie. Right off to shift my sheep.
Al Just before you go and shift your sheep, Juddy, I would just like to summarise a few of the take messages that we saw today.
Juddy If you must.
Al Yeah I will, if you don't mind. But what we want to leave you with is just reminding you why white clover is really important to your farm system. And remember, in the past, it was very much about animal productivity. It is such a big deal for your animal performance both in live weight gain and milk solid production. I do believe we shouldn't underestimate its role in pasture management. Pastures are more palatable when you've got good clover content and that has big ramifications for the overall quality of your pasture. And the third thing which has now become the first thing is the nitrogen fixation associated with white clover, which we cover today. Remember that secret message? One kilogram of white clover growth is about 28 grams of nitrogen. You do have to grow a lot of white clover to get a lot of nitrogen, so that should be a key driver for everyone. I'll leave you with a couple of other key points. Remember your sowing depth, focussing on around one centimetre in a nice fine firm seed bed and possibly with a little bit of seed broadcast on the ground. And always remember light is the driver to white clover success, so the more you are shading your pasture, the harder you're going to find it is to maintain high white clover content. So remember good grazing residuals, keeping a bit of light in your pasture and white clover should flourish.
Juddy Thank you very much for sharing the last 40 minutes with us. Hope you learnt something! If you've got any questions, please contact your local Agricom person.