Episode 136: Working With Unique Climate Conditions with Frederik Larsen

Hi friends. Welcome to the Regenerative Agriculture Podcast. I have so much fun on this podcast, having enjoyable conversations about topics that I'm passionate about, that I care deeply about. And today I've really been looking forward to a conversation with a remarkable individual for some time, Frederik Larsen from Denmark. Frederik, thank you for being here. Thank you for being willing to share some of the things that you've been working on and that you've been talking about. You know, here in the States we have particularly innovative farmer that lots of people enjoy observing and interacting and kind of scratching their heads about being Jason Mauk from Indiana and all of his work with companion planting and relay planting and some of the unconventional ideas that he comes up with with his imaginative brain. In some ways I think of you as being the European version of Jason Mauck, but perhaps with a more scientific approach or a, a more grounded approach and grounded perspective. But anyway, I don't want to give all the good stuff away. Tell us a little bit about your background, your story and the scope of the work that you're working on.

Well, thank you very much, John, and thank you for having me here on the podcast. I'm a regular listener to your podcast. I've been looking much forward to our conversation today. Well, so my background is a agronomist. I have a Master's of Science degree. So you know, all the fundamental entry to our egg business is there. I work as a full time agronomist helping my farmers in Denmark and abroad, mainly in Eastern Europe, to, to transition their farming systems to some of these, you could say traditional conservation egg approaches of less tillage, cover crops, crop rotations. And very fortunate that I have a family farm as well, which I can site a farm to the side. And the core principles is that I want to develop the farming systems I preach about at our family farm. So doing some good old practice what you preach at the family farm. And that's just so fun and exciting to play around with the agro ecosystem to maximize sunlight capture and so we can have a lot of biomass and carbon cycling in our soils. That's one of my key drivers in.

Some of the work that you're doing. My attraction. I've been following your work on X for a while and I've been intrigued by some of the work that you're doing with companion planting and with relay planting with different types of crops. But how did that come about? What was the original thinking that led you to think that having some of these plants interact with each other might be a Different approach or a better approach?

Yes. So just to set the stage, we are in Denmark, in the middle of Denmark and Europe and Denmark in general are quite further north on the globe than the US So just to get your American listeners, an idea of the amount of sunlight we have is that we farm what would be north of Edmonton or south Hudson Bay. So we have a lot of sun in the summer and basically not much sun in the winter. So that limits our growing season. We don't have killing frosts and all the cold stuff they have in Canada, but we have a quite intensive growing season from roughly middle of March to middle of October and then there's not much sunlight to play around. So our main crop is winter wheat which we can grow to high yields. That would be normally we aim for 10 tons to the hectare of 10 metric tons to the hectare of winter wheat. And so that's the core component of our crop rotation being a no till and non plowing farm for 25 years. And true no till is last 10 years. We really try to cycle in this component of COVID cropping, but we don't really have much time for our cover crops to really grow and sequester a large biomass because we harvest our winter wheat in the first week of August and then we need to get a new winter series in by end of September. So that really means that we only have August, September, maybe half of October for our cover crops to grow. So we've been playing quite a lot around with relay planting our cover crops so broadcast them surface seeding a couple of weeks before the winter wheat harvest. So we have already our emerging cover crops going in the field and yeah, so that was the initial entry to some of these relay planting approaches.

What do your rainfall patterns look like in terms of both amounts and then distribution through the year? Are you growing a winter crop on the same soil year after year every year?

Well, so there's a lot of components going into a good crop rotation, especially wheat management. So we cannot grow winter cereals year after year after year because of grass seed pressure. In general, we are evenly distributed with our rainfall throughout the year. We are normally around 7 to 800 mils of water a year with a tendency to a little bit more water during the winter months and less in the summer. That said, August is our long term average is August is the most rainfall intensive of most rain in a month. But that's also where we have a lot of evapotranspiration. We also use a lot of water in the summer, but it's Reasonably easy farming.

Yeah. That's also the same month where you have peak cover crop or intercrop need and no crop in the ground.

So normally it's easy to establish, especially if you no till seed your cover crops in the early August because there will be sufficient soil moisture. Problem is that before we get the crop in the ground, it emerges, it get leaf cover. We almost play around with a couple of weeks where we don't catch any sunlight. So we, it's quite clear, and that's both on my own farm, but also my, my client farms, is that if you lose just one day of planting time with your cover crop in August, that will be almost equal to a full week of growth in late September. So every day counts. Chasing the combine with the COVID crop seed drill. Wow, that's just so important.

You made mention of that. You are, you're experimenting with planting ahead of harvest. How did that evolve and what does that look like?

So the idea is that we like to say that the day before the first rainfall event in July, we like to spread our cover crop seeds with the fertilizer spinner or we have some smaller spinner discs on the, on the spray boom so we can get it out there because then the, the summer rain will get the seeds to the ground surface and let them grow away ideally. So they're already there when we a couple of weeks later come with the combine and get the weed off. That was the initial idea. And because normally pre harvest in the middle of the July, you have reasonable amount of farm work available and you're not too busy with the harvest yet. So it's a good time of the year to get some important stuff done because once the harvest train catches in and you are really busy getting the crop off the fields and you also need to get window oilseed rape drilled and you all of a sudden you have a huge workload peaking at the same time. And that's where the ideally it's great to have the COVID crops in the ground already by 1st of August.

What are the types of COVID crops that you're planting ahead of harvest?

So in our climate, radishes works really great to catch some nitrogen veggies, works great for fast coverage and some early nitrogen fixation. We like phacelia as well, buckwheat, maybe some crimson clover as well. So that's our, I would say that's our five main species.

How do these cover crops then get terminated? Are you terminating them when you're planting the following crop or is the expectation that some of them will occur. What does the rest of the COVID crop cycle look like?

Yeah, so we have two options. Either we can keep the COVID crop as a reasonably short 8 week summer cover crop and then we'll get in, we will drill in a winter cereal afterwards, or we can keep it until maybe late October and or basically just let it grow all autumn and then the winter killing frosts will take care of most of the COVID crop and then we have a normally it will winter kill and then we have a clean field for some spring crop. Drilling actually to a side note, is actually a pretty neat thing to roll the COVID crop on the winter frost. So when we get the first night of maybe negative 5 Celsius, we will go into in the early mornings and roll the COVID crop to ensure a good kill by the rolling. It works quite, quite good actually. If you have reliable frost, it's a neat way to fasten up your nutrient cycling and get those nutrients available earlier for some early spring planting.

Let's talk about that a bit more. Are you saying when you described how far north you are from a latitude perspective? The assumption that I made in my mind was that you also have reliable hard freezes relatively early in the fall, but you might be getting enough climate buffering that that is not happening.

Exactly.

Okay, so what is the when you are rolling cover crops for a better kill, what are the, what are the advantages that you are seeing with nutrient cycling in the spring? How much more readily available are the nutrients?

Because our main cash spring crop is spring malting barley and not corn, we need to go in early, ideally in March already to get our spring barley established. Which means that we need to get bigger nutrient cycling already early, late in autumn or during the winter, so it's ready for our spring barley to do some growth. What happens with our cover crops is that as soon as they flower, their stems will lignify and become less digestible for the soil microbes and all the breakdown processes. Which means that if our cover crops flower, which they normally will do late in the autumn, by rolling it at the first hard winter freeze, we can get a very cheap breaking effect and all the it will just kind of splinter like glass. And we will start this process. And from a seeded drill planter perspective, it's also much easier to drag your implements through the field while you're not having 1 meter long lignified flowering stems of radishes, etc.

And just to clarify for our listeners, I'm, I'm imagining that you're describing rolling while the plants are Frozen while there is a hard freeze. So you have to be. Yeah, you have to be out there in the night and early morning.

Yeah, yeah, yeah. It's, it's not, it's not crimper rolling, which I'm aware that some guys will do with the winter cereal, rye, etc. And we might need to play around with that for our short term summer cover crops. That could be a thing if we have sufficient biomass to compete against the weeds. But just good old traditional roller is pretty sufficient for these early morning winter freeze crops.

So this raises an interesting discussion, interesting conversation. It's a recurring question that as people begin thinking about developing biological activity in soils, there's this recurring question like what is the value of biological activity during the winter months? And our experience in our work at advancing eco agriculture has always been that there's tremendous value and tremendous nutrient release that occurs that biological activity. Even when the soil is frozen or frozen on top. Certainly it slows down, but it never entirely stops. And there's tremendous accumulative value there by the following spring. How are you thinking about biological activity during the winter months?

Well, the old saying used to be that below 5 degrees Celsius in the soil there was limited cycling and limited biological activity. The recent findings, both at a university level, but also what we experienced in the field, is that there's actually a remarkable activity in soils as long as they are not deep hard frozen. So most of the time it's very unlikely that our soils and then we would get the first killing frost, normally late of November, early December, but it's only a few degrees negative. So it's not these massive freezing temperatures. And as soon as our soil is wet, not frozen in the, in the profile, I'm pretty confident we will have microbial reactivity. And the value is that we, especially in our winter wheat based cropping systems, we need lots of nutrition early because our winter wheat will do in our climate. It will really start elongate in the first week of April through a month and start flowering in the middle of late May. But it's huge nutrient demand when the wheat starts to elongate, and that's why our soils are still reasonably cold.

And I would imagine that one of the benefits from the rolling, in addition to getting a good kill and beginning or accelerating the microbial degradation process, is that it also puts it into close contact with the soil. So you accelerate soil biology.

Yeah, you break it up in finer particles and it will then easily be more dragged down by earthworms and other microorganisms into the soil for sure.

So I don't know if we fully captured the thought. We went down a different track when you started talking a little bit about your crop rotations. So you mentioned being wheat centric, but you've also mentioned other crops, the malting barley, canola, etc. What does a typical crop rotation look like?

Well, so our cash crop rotation, which is quite typical for Danish arable farming, is that we will have a winter canola, then a winter wheat, then we will have a spring malting barley and then another winter wheat and then some producers might already go back to winter canola again or you'll do, maybe do a second weed and then back to winter canola. So we are not too tight on the winter canola. I don't have a good argument for it, but I think our soil types and the drainage and our biological activity from a club root perspective justifies that. At the moment we are only having three gap years before we are back into winter canola, which is a profitable break crop for us to grow.

So if I'm following correctly, you have three gap years for canola and you have three and sometimes four wheat crops in a six year period.

Yeah. So ideally most farms would try to have 50% of the acreage in winter wheat and then some break crops which would be winter canola, spring malting barley, maybe some spring oats to cycle around it.

So given the early nutrient requirements that you have in fairly cold soil, and this is true for both the malting barley and for the winter wheat, in addition to rolling cover crops and facilitating microbial digestion during the winter months, what is your traditional nutrition management look like to produce the wheat yields that you're producing with cold soils in the spring?

So for a high yield winter wheat scenario we. Well obviously the winter rolling doesn't apply for the winter wheat because it's already in the ground by 20th of September, we might be lucky to grow a good summer catch crop in the in six to eight weeks before winter wheat establishment. Then we have the winter wheat and then in principle we will start it up roughly 1st of March with some units of nitrogen together with sulfate and then we will do the main amount of, well almost rest of it of the nitrogen by roughly 1st of April before stem elongation. So it has this as much fertility available for its elongation phase. And normally when we measure it in, in the Danish climate it's not, not just our farm, but in general Danish high yield winter wheat fields will almost take up between five and seven units of nitrogen each day from stage 31 till early flowering. So it's a huge drain of nutrition. It needs to soak out of the ground in that period, which is actually quite exciting. And then, and I think it plays a lot with the liquid fertility management as well, which we are, it's gaining traction I would say because it adds more flexibility to our nutrient timing. So traditionally we will make sure that all the nitrogen between 160 and 200 units of nitrogen per hectare, I guess it's almost the same as pounds per acre, will have that available by stage 31 when it starts elongating. Nowadays we would like to, that's the ambition of some of my farmers and my own farming system as well. We would like to maybe do a 5050 nutrition perspective. So we have half of the nitrogen available by elongation and then we can foliar feed the other half or maybe 75% of the nitrogen as we go until past flowering. But it's, it's early days in that perspective in Denmark.

What led you to consider that approach of doing a 5050 split and doing more foliar applications?

The arguments for the 5050 split is that we don't want to get left behind in the way that once the wheat starts really growing, have a huge nitrogen demand, we fear that it will be difficult to get enough nutrition to the plant as it grows so quickly. Documents for the foliar feeds are definitely, I would say right now it's mainly a use efficiency perspective and it's a management perspective because by foliar feeding we can still apply nutrition to a dry out soil when we have some dry periods in the spring, which is less likely with our dry based fertilizers. And then I'm sure which, well you're, you're the expert that perspective but I think there's much potential for the banded nutrition and all these other things with lodging and plant health and all the other things. But at the moment it also adds management flexibility.

Yeah, there's lots of pieces that tie into, yeah, tie into nutrition management with foliars. So one of the conversations that I wanted to really get into, we've been talking about some of your summer cover cropping, but recently I've been, I had a conversation with, with Ian Gold on the podcast recently and I've been very intrigued by this conversation around companion planting and intercropping and the idea that the information that I had been exposed to and I was familiar with there was kind of this default perspective that plants are inherently competitive with each other. And some of the experiences that I've had and that I've talked about have led me to realize that that is not an appropriate to default position. That certainly is frequently true, but it's not necessarily universally true. I'd love to hear your perspective as you've been thinking not just about summer crops, but also planting, growing various plants together. I'd love to hear more about what is it that you're doing now and how did that come to be?

Well, because of variability. When we relay broadcast seeding our cover crops, we were initially looking for a more reliable cover crop and a more vigorous, dense cover crop growth because as I mentioned, ideally some summer rain, you spread it before harvest and stuff like that and you have your cover crop going, but then enter some summer drought into some flood, grazing, residue management, all these other components in the system and you have unfortunately in our situation, a quite variable success ratio. So some years we would get good dense summer cover crops, other years it would be almost a complete disaster. And it's expensive to buy the seeds and get established. So I got introduced to some different topics, especially Andrew Howard's Nutfield report back in 2016. He's an Englishman in Kent and traveled the world and on some of the pages there was these stories about French farmers doing alfalfa based lemming mulches. And unfortunately my French is not that good so I'm not that good at reading French sources. I'm pretty Anglican orientated in that perspective. But anyway it, it sparked some ideas and in 2018 we put in our first small trial field with that was actually some father beings on the zone with alfalfa and then we took it for a couple of years in a rotation and these last couple of years we have scaled it up to some larger commercial sized fields. And the whole idea is that we want to fill our non cress crop periods in our rotation with the alfalfa. So ideally we get our alfalfa established by under sowing together with our winter canola and then once we one year later we get the winter canola off the field and the alfalfa is already down in the bottom of the canola stubble and it will regrow and then we put in the weed and then we put in maybe some winter oats and then some winter wheat and then we are four years down the road. So ideally we need four seasons of alfalfa growth while having annual cash crops.

All right, there's a lot to unwrap here.

Yeah.

How do you manage the alfalfa while planting or when Planting a grass crop or a grain crop such as the wheat or the oats. And, and how do you avoid having the alfalfa completely dominate and out compete the grains?

That's the neat thing with alfalfa. And I think a lot of people are scared or a lot of farmers are scared of the vigorous growth of alfalfa. But I would encourage you and all farmers which might be close to an alfalfa field and have a look at when does it actually grow in. I'm sure in the Midwest. And you get different winter dormancy ratings on your alfalfa and especially if you're in the lower end of the dormancy groups. In our place we grow Dormancy Group 2 Alfalfa, so very winter dormant. But I'm sure some areas you will also, I guess you could make it work with a group 3, 4, 5 as well. But in cold climates where we have winters, the alfalfa don't grow in the winter and it actually almost disappears throughout the winter. You have an almost virtually empty field because the alfalfa is just this tiny little, very few green leaves. So it leaves a lot of room open for weeds. But it also leaves room for our winter cereals to really do some winter growth. And in our climate, the winter wheat does quite a lot of growth from its seeding time until elongation because it's. Well, we don't freeze down. So we, our winter wheat keeps the green foliage through the winter, which our alfalfa don't. And that's where the neat thing comes in. So we have a time wise complementarity effect between our winter cereals and our alfalfa, which is pretty nice.

So I understand that during the winter months. But thinking about the dormancy break in springtime, and I think depending of course on where you are here in North America, dormancy break can occur quite early. It can occur in late April, early May for certain. Usually we would have dormancy break and I'm thinking about where wheat would be at that point as well. And it's, I suppose you would have wheat that already has 8 to 10 inches, maybe 12 inches of growth on it at that stage. So I think what you're describing, if I'm understanding correctly, is you're saying the wheat actually produces enough vegetative growth that it out competes with the alfalfa.

Well, in our climate it doesn't necessarily out compete but it gets a really good head start. So our weeds in Denmark will elongate 10th, 15th of April roughly and it will head out late May, which is the average heading date whilst our alfalfa, they will break dormancy mid April. So one week, two weeks after the, the winter wheat. But it will not do much growth because the wheat really at that time where the wheat elongated really shoots ahead. There's important component is this, which is fertility management, but I think we'll get back to that. And then there's a, a necessary growth stunting of the alfalfa which is really important because once the alfalfa starts to grow, even though the wheat gets a good head start, the alfalfa still has an opportunity to almost outcompete the wheat. And that's where you, I'm aware some guys work with row mowing where they will romo between the wheat rows. In our perspective we, we don't, we don't have a row mower. It's a very expensive investment. So we play around with a little bit of very small doses of the right herbicide is really effective at making a tough time for the alfalfa while our, our wheat will grow quite nicely.

So you're trying to stunt the alfalfa. How do you time that? What's the optimal timing window for that from a plant growth perspective?

So I need roughly 20cm of growth on the alfalfa because then it has some green leaves for my herbicide to stick on. And at that time the weed will already be a good way into the elongation phase. And then we will apply some of these low doses of a broadleaf herbicide which is very common in most winter wheat growing. So you get a lot of value for almost no bugs. And then the alfalfa will have a really tough time almost growing back into the ground. And then by the time of flowering there will be almost no alfalfa in the field and the wheat will be big biomass harvesting, sunlight, etc. And especially this year it was quite, quite interesting for me. I spent most of June walking the fields like where's Delfalfa? Oh no, did I, did I kill it? Where is it? And then the last two weeks before combining the field was yellow and then it almost started to regrow green and purple flowers all over. And let us just say it was a good sunny day with the combine. Otherwise it would have been pretty tough combining. But it was, it was really nice to see how the alfalfa out of nowhere just was back in the field capturing some sunlight.

Let's talk about the potential challenge of combining. I want to understand that better. Was the, was the alfalfa coming up in height where it was getting close to being the same height as the wheat plant or was it just the high moisture content of the stems down low?

Some areas it was 20cm higher than the wheat.

That could be very entertaining in some conditions.

Yes. In our conditions we don't have a stripper header. I think a stripper header would be a really neat addition to this farming system because then we could just strip the heads off the weed and then we don't have the straw and some of the green alfalfa foliage through the combine. Alternatively, swathing would be very interesting to play around with. So if we put the big belts water in there and just leave the weed for maybe just two or three days on the swarf, then it would much easier go through the combine because then you're taking most of the tugal pressure out of the green alfalfa and it's easier combining so. Well, I'm not too concerned about it really. It's. It's just the only limitations I accept in farming system is biological limitations, technology, just, just an engineering thing which can be solved.

So in these conditions where the alfalfa had this late season vigor and comeback, what were the moisture conditions, how common would that be to expect? Is there a possible need in some climates, in some environments for a second herbicide pass later? And how might we be thinking about that?

That could definitely be a thing. But it's most important herbicide timing for the, you could say, I think the, the proper word is chemical mowing or just stunting of the alfalfa. That's in the early elongation phase because that's really where your winter wheat builds its yield. And then a possible second timing could be sometime around flowering time of the winter weed in order to stunt the alfalfa once again. So your, your weed can have a good period of sunlight capture and building its yield. The really neat thing from a wheat perspective in the winter wheat field is that when it starts to yellow, there's still quite a lot of time until combinable. And in that time when the window wheat senescences and yellows up, that's where the alfalfa starts to regrow and be green and capture some sun. And that's nice both from a sunlight capture perspective, but it's also really important from a wheat competition perspective because we don't want all our small annual weeds to grow away at that time. So that's where it's hugely important that we have already introduced a strong competitive crop to stay green at that time of the year.

Another advantage of this, of having constant green is that you're also, you're capturing sunlight energy, you're bringing energy into the system. You're also capturing and cycling the carbon that is in the system and preventing that from being lost.

Yes, exactly.

Yeah. So this is a fascinating topic I have for all my listeners. I have a pretty big smile on my face because I see so much potential and so much opportunity. Yeah. But you mentioned having wheat and then going to oats and then back to wheat with the alfalfa. How has, how has the oats management been? Have you needed to mow the alfalfa? How is that different from the wheat, if at all?

It's not much different. It's reasonably new to me to grow winter oats. So I'm only one season's experience of winter oats. But growth, timing and management, it's not too difficult do too different from the winter wheat at the oats are much more vigorous and a larger, more competitive crop. So I had much less growth control of the alfalfa needed than I initially thought. So it was a really strong competitor against the alfalfa. I think in that cases it might be less important with the early elongation timing and maybe more important with the close to flowering timing of the. Of the stunting in order to build the oat yields and not making it too tough on the alfalfa.

And to clarify, I think you said you had this one year experience with winter oats, not with spring oats. Yeah, exactly.

And just it, it might sound a little bit confusing, but this system where we overlay our cash crops with alfalfa in order to get this growth complementarity of timings. Ideally we want winter cash crops which are early harvested in the middle of summer because then we want our alfalfa to grow in the autumn. So it doesn't really play around that neatly with spring seeded cash crops like spring oats or spring mulching barley because then we get a 2, 2 uniform growth window and don't spread it out. We need to separate the growing the main growing windows in that perspective.

We've spoken about the managing the alfalfa during the spring period with chemical mowing. But let's go to the other end of the season. How are you then managing the alfalfa in preparation for planting?

So I'm an experienced grass seed grower and I didn't put much emphasis on that. But grass seed and herbage seed growing is a big thing in Denmark and most farms are either growing or have experience growing herbage seeds. Including grass seeds. And that's perennial farming as it's really nice. So you'll get in one, one crop and then you will harvest the grass seeds for two years. So you play around with three years of harvest from one seeding and that's a very exciting topic. But the main importance is post harvest mowing. You need to reset your perennial crop in order to get nice, good uniform, even regrowth after harvest. It's not too different from hay cropping and stuff like that, but it's. Everything comes back to the mowing. Nice, uniform, four fingers height, uniform mowing. And in our window weed and the alfalfa perspective, we try to cut the weed as high as possible just to cut the head ideal. This ripper header would be nice. And then right after the combine, the big disc mower goes in the field and mows the field right down to four fingers height in order not to damage the, the crown of the alfalfa too much. But also to, to get, you could say the old deceased leaves of the alfalfa are still there, maybe being stunted a little bit with, with the herbicides and they might still, it might still be in there a little bit. And then you, you remove all the, the old foliage and then you alfalfa regrowth nicely. And the mowing is important.

So this, this mowing period, this is occurring post wheat harvest?

Yes.

All right. And then are you mowing again right at planting or right before? How are you planting into the alfalfa?

So ideally I would like to, to make well a baleage so it's, it's not immature enough for haylage, but take a forage cut, remove it out of the field and then no till in my window wheat for example, or windows.

And you mentioned your planting period earlier, but your planting would then be happening in late August to mid September.

Last week of September.

Last week of September.

Last week of September, Yeah. So ideally I will get my winter cash crop out of the field and get the field mowed by 1st of August. And then I have ideally eight weeks of growth from 1st of August to the 1st of October. And then I will put in a late seeded. In that perspective will be a late seeded winter cereal afterwards. And the neat thing is that in those eight weeks of time, the alfalfa being nitrogen fixing and the biomass it makes, it's not unlikely that it will do 100 units of nitrogen in the harvest cut. And my winter cereal don't need that. My field don't need 100 units of nitrogen by the first of October. So by by mowing the field, harvesting the alfalfa for ideally for dairy feed or beef feed and feedlot feed during the winter, I can get the manure back in the field in March, where my winter weed really needs the nutrition. So that's the idea.

What's the scope of your experience with this alfalfa companion planting? How many years have you been working with this and what have the yield responses looked like on the cereal crops?

So my initial experience was based on a small trial field I have close to our homestead where I do that. That was back in 2018. So, well, that be six years already. And then three years ago, I put in the first out of three larger commercial fields. At the moment we have three larger commercial fields. And for us, commercial fields in Denmark are 25 hectares each and.