Episode 97: Integrating Trees Into Working Pastures with Austin Unruh

Hi friends, this is John. Welcome back to the Regenerative Agriculture podcast where we talk about all kinds of fun stuff related to agronomic sciences and human health and cultural management practices that can regenerate our ecosystems that we're a part of. I've really been looking forward to this conversation. My guest today is Austin Unruh, who is perhaps of the various people I know of, he's on the forefront of innovating and leading and thinking about opportunities for silvopasture that can be developed in the future and that and is actively doing this work in the space now. So, Austin, thank you for joining me here. I've really been looking forward to this discussion. Can you tell us a little bit about your journey, your pathway and the work that you're doing today and what got you here?

Absolutely. Thank you, John, for having me. Well, so I'll introduce myself a little bit and the company that I run. So Austin Unruh and I run Trees for Grazers. And as the name of the company suggests, our focus is indeed on integrating silvopasture, integrating trees into pastures. And it's been a very circuitous route in order to get here. By no means did I intend to get here maybe 10 years ago. If you told me 10 years ago that I was going to be leading a silvopasture focused company, I probably would have asked you what silvopasture was. So I did not grow up on a farm. My dad grew up on a farm, a Jersey dairy in Minnesota. But I myself did not grow up on a farm, but came out of college wanting to get my hands in the ground and wanting to do something where I had a lasting impact in the natural world. And I wanted to have something involved with agriculture. I had read the book Restoration Agriculture by Mark Sheppard and that inspired me to the vision of landscape scale agroforestry and wanting to see agriculture that was both economically and also ecologically viable, sustaining, and led to thriving both ecologically and economically. So that was kind of my guiding star, as it were. And I started out with a company, well, company. It was just me. It was just me doing work on riparian buffers. I'm located in southeastern Pennsylvania, Lancaster County, Pennsylvania. For better or worse, we send the most pollution down to the Chesapeake Bay. So there's a lot of water quality related funding available for Lancaster county to do stream related water quality related cleanup. So that was my entry into agroforestry was through riparian buffers from a conservation perspective. And once I got into that I had a number of clients who were also grazers. They were dairy grazers, and I was working with them to get trees established along their streams. And they said, this is great, but how do we get trees established in a pasture? Because I have cattle out on pasture, they're grazing all day long, and they need access to shade. And I had done some studies in agroforestry at that point and knew that there weren't very many tried and true methods of getting trees established at any kind of scale. And for a budget that works for a farmer. You can get trees established if you fence out a big area and plant a big tree. But most farmers don't have the kind of money to do that at a large scale. Right. So we just started experimenting. We started playing around with different methods of protecting trees and integrating them into pasture in a way that was minimally intrusive to the way that the farm operates. Right. We don't want to have to completely take the. Take the land out of production in order to get those trees established. We don't want to have to change the way that the farm is managed or operated in order to get those trees established. We're also given that we're in Lancaster county, land goes for anywhere from 30 to $50,000 an acre or more. So. So it does not pay in this area to take land out of production for five years, 10 years, until the trees are large enough to get the cattle in there. So that was our start in the silvopasture world. And over the last number of years, we've just refined our techniques for getting trees established and have also worked on other things, like starting to improve the genetics, the tree genetics that we're working on, and finding more funding for farmers so that they can reduce the cost of investing in trees for a silvopasture system. So that's a little bit about how we got to where we are today.

Thanks, Austin. Let's dig into some of these pieces a little bit further, actually, a bit more on the context. Can you tell us a little bit about the scale that you're operating on currently? Or maybe that's not the best way to ask the question, but how many acres have you planted at this point, and how many acres are you expecting to work with over the course of the next several years?

So, so far, we've done. I think it's about 400 acres. I'd have to go back and look and see exactly what our acreage count is to date. But I do know that we've planted trees on 25 farms, all active farms. So not hobby farms, not homesteads, not rich people farms where they don't really care about the production. These are all active working farms, most of them dairies. And 90% of our projects so far have been in one county. It's been Lancaster County, Pennsylvania. And anything outside of that is in just the neighboring counties within the one hour radius of where we are located. So in our context, a little bit more is we don't have really big farms around here. Our farms range from anywhere from 40 acres to 200 acres. Is our largest farm that we've worked with. And we are now doing second and third phase plantings on several of our farms. So we've got 25 farms that we've done so far and then we have another 12, 15 going in next spring. And the speed at which we're doing plantings is only going up from the air.

Yeah. And for our listeners, if you're not familiar with the local context of Lancaster, Pecania, Pennsylvania, it's home to the. One of the largest Amish communities. I think the third largest Amish community in the world. And so this is reflected in the smaller farm size and very intensive management. And as you can imagine, with 30 to 50,000 an acre land cost, there is no margin for poor management. That ceased to exist some time ago.

Exactly. In our area. So we focus on planting trees into pastures because most of our area is open pastures. Right. We don't have wood lots that people have left except for on the least accessible lands. And we don't have brush to thin to create silvopasture. No one lets their land grow up in brush around here.

Yeah, doesn't exist. It's an interesting landscape to drive through. It's a beautiful landscape to drive through. But very manicured.

Yep, very manicured.

Yeah. So the good news about this, because of the management intensity and because of the cost of land, what you're describing, the scenario that you're describing, the work that you're doing Austin, is if the way that I think about it is if it can be applicable and relevant and add value in that type of an economic environment, it's justifiable almost anywhere. And that's. I'm looking forward to getting into that discussion with you a little bit. But let's talk about the establishment process. Planting trees in pasture where you're grazing livestock, sounds like a challenge to me because livestock love trees and young trees. So what's the establishment process look like and how do you get this to work on A working farm?

Yep. It's. Thankfully it's not rocket science. If it was, I would not have figured it out. So the R system is fairly simple. And this is the system that we use for most of our projects. And depending on your context, you can adapt it, you can do use different protection methods. But this is the system that we have developed is we use a six foot tall tree shelter. And that shelter has a plastic tube and a fiberglass stake. The upside of a fiberglass stake is it does not rot, it is flexible if cattle do rub up against it. And it's an electrical insulator. So that tube is what protects the tree from browse. And then we run electric fencing along rows of trees. So we usually are establishing trees in long rows and we're running electric fencing along those rows of trees. And there's different ways that we can configure the fencing. Sometimes we'll run it at the height of a paddock division fence and then we just use a single strand of fencing. Sometimes we will wrap a strand of polywire around that tube as well to protect the entire tube from, from being rubbed up against. So that's the very basics of our system. And then voles are something that we deal with, little rodents that like to girdle our trees. Orchards deal with this all the time. And we just need to dissolve for a little bit differently because we're in organically managed farms and there's a whole lot of, whole lot of forages, a whole lot of places for those voles to hide. So we can't do clean culture and there's a whole lot of forages to work around. So what we use to protect against voles, at least now, is we use a 9, 10 inch spiral guard. It's a vinyl guard that protects the base of the tree from girdling. And then every fall we go around and we put castor oil, it's a combination of castor oil and blood meal inside of that, the tree tube to try to repel voles inside of there. So that's what we're doing for voles. And then you layer on a really big thick layer of mulch, wood chip mulch on top of the trees, right around the base to get them a good start, get a more fungal environment going and conserve the moisture right around the tree. So that's the basic way that we've developed to get trees established in pastures.

You're conserving moisture and you're also avoiding moisture competition with the grasses and the forages that are around them. Which are very effective at sucking all the moisture out of the soil. How effective you described your vole management process. How effective has that been for you?

I wish I could say that we've had a long time to study this. Last winter was the first winter that we went through with those spiral guards on all of our trees, all of our new trees that we put in the ground. Last year we were able to go through the winter and see and we had very, very, very little vole damage on those trees, which is great. And it's a big difference from previous years where you'll come up to a tree that's 6, 7, 8ft tall in the spring and you, you admire it and you give a little bit of a pull and the whole tree comes up from the roots because it's been girdled all the way through. Last year we did not see that. Now those spiral guards are providing protection from above ground girdling. And that's where the castor oil product comes in. Is that is supposed to repel below ground rodents, gophers, moles, that kind of thing. So that's what we're using there. I don't know how it'll work, but it's an added layer of protection and I'll buy any insurance that I can against moles.

I want to also speak about the establishment costs and population densities. Some more of the nuance of how you're building this out. But I think in order to have the context for that conversation, we first need to speak about what are the desired outcomes? What are the goals? When you think about farmers planting trees on land that's worth $50,000 an acre, we've spent the last several hundred years removing every tree possible from land that has that type of economic value. So what are the desired outcomes? What are the goals that these farmers are expecting to achieve from planting trees on pasture?

Absolutely. So envision, if you would, a savanna ecosystem with a combination of grasslands and trees interspersed widely throughout that system. That's about what we're aiming for. So we're not looking to recreate a forest because again, all of our clients are, they're grass farmers. Whether they're doing dairy or beef or sheep or whatever that they're raising, they depend on forages. So we're not looking to recreate a woods. But we also don't want a wide open space without trees because trees can provide certain key benefits to these grazing operations. So the number one thing that brings most of our clients to us is shade. Livestock just perform better when they have access to shade. And when it comes to shade, we. What we want to avoid is having shade being distributed in too small of an area. So where you say you have one tree or just a handful of trees or maybe a row, like a row, that's the edge of a woodlot where the livestock can go for heat stress relief. But then they're moving all of those nutrients underneath that one tree or into that one area, and. And they are over compacting and overusing that one area. So what we want to do is we want to create a silvopasture system where the shade is well dispersed through the pasture. We can do that through planting our trees fairly evenly. We can do that through having trees with a fairly small canopy, so we prune off those lower limbs and create a fairly small canopy that is high up on the tree, as high up as we can reasonably get.

That would make the shade move around.

Exactly, exactly. So that's the kind of system that we want to create. So shade is what brings most people to us. But any tree can provide shade. So we want to select for trees that are going to provide shade plus additional benefits. So that can be honey locusts that are going to drop pods in November, December, January, and add additional feed energy during the wintertime. It can be persimmons that are going to do a similar thing, but with fruit. I was talking yesterday to some farmers who were very excited, actually, Alvin Peachy, who you've had on this podcast before, he was very excited about being able to have apples and even mulberries and persimmons and things that are going to drop, could bring wildlife and particularly large deer. And that's a very common thing that we see is wanting to integrate trees, both for the livestock, but then also for wildlife, whether that's deer and hunting or that's birds or whatever. Like a whole bunch of our clients want just to see more habitat, want to see more biodiversity on their farms. But so shade and then feed during critical times of the year. I should stress this, that what we want to see is we want to see these trees be able to reduce input costs and increase output for the farm itself. We're not really focused on tree crops for human consumption. On a homestead scale, yes, I think every farm should have some trees for homestead use, for homestead resiliency. But most of our focus is on reducing the cost of doing business on that farm and increasing the economic output on that farm. So take honey locust. A good pasture of honey locust can produce hundreds, if not thousands of pounds of feed, additional feed, depending on how many trees that you're planting per acre, that is able to create and add an energy source, a high energy source during those months when our forages are low in energy and livestock need more energy in order to keep condition during the winter months. And the same thing would apply to others. Persimmons. If someone is feeding hogs or poultry, then we can add in mulberries or acorns or chestnuts or a whole variety, especially when it comes to hogs, because they can eat just about anything. And again, our goal is to reduce the feed cost for those and be able to have a stronger bottom line for the farm operation.

There's so many pieces that you've mentioned, Austin, that I'd like to unwrap further. But I think the key central point is you mentioned reducing inputs. But then really the line that really catches my attention is increasing profitability. And so there is, I think many people have this inherent question. When you think about planting trees close by crops or into pasture, there is almost this inherent assumption that the presence of trees is going to reduce yields. And I have some thoughts on that that I want to share as well. But I'd like to get your perspective on what do you see happening to. There's of course you described the additional value, which I also want to get into, of the additional calories that these tree crops can provide themselves. But what do you see happening to the yields and the overall crop performance of the underlying forage base?

I'll say this, that we as a business have not been doing this long enough to see a lot of effect on our projects. So our first silvopasture planting was in spring of 2020. So it's now just finished its fourth growing season. So in the scheme of things, not very long for trees. But from the research that I've looked at, Virginia Tech in particular has done quite a bit of research on forage production in silvopasture systems. They have found that if you get shade anywhere in the 30 to 50% range, so 30 to 50% canopy cover, that you're seeing about the same forage production. And you should see stronger growth during the summer months. In particular, most of our clients are grazing cool season perennial forages. And as the name suggests, those forages want to be cool, they don't want to be over overheated. So they experience heat stress during the summer months just like livestock experience heat stress during the summer months. So by having a moderate shade again, we're not looking to recreate a forest, but by having a moderate level of shade, we're able to reduce the heat stress on those cool season perennial forages and allow them to grow better during those summer months, which is the most critical time of the year. Most critical time of the growing season, I should say. Most farmers don't need additional forages during the spring. Right. There's so much forage that you can't even keep up with them. And it's during those summer months that you experience the summer slump. And having some shade, especially during periods of drought, are particularly valuable. One of our consultants, he has his own farm that he established silvopastron a number of years ago. And so the trees are a little bit more mature. And last year we saw a pretty significant drought in his area. And he noted that the forages grew the best in the morning shade of his tallest trees because the dew was able to settle there and be more effectively used than the rest of the forages. So that's just one small anecdote.

Well, the anecdote matches with and the experience you're describing matches with what I am learning about how plants respond to light, how plants respond to excessive light. And you know, when we think about the simple phenomena of our yards and how grass grows around trees in landscaped areas, it can depend on the tree species that certainly has an impact and also in how the grass is managed and maintained. But if you have grass with a well developed, robust root system, in other words, it's not cut off an inch and a half above the soil surface, and you have trees that aren't providing excessive shade, then the grass actually grows more luxuriously and better underneath the trees than it does anywhere else in the lawn. Like I've observed this dozens of times and I've been learning this. There's this interesting phenomena where it's also related to the summer heat period. I'm beginning to realize that it's not just the heat stress, but there is in fact such a thing as excess of light. And that when you have too much light coming in, the plants are not able to utilize all of it and actually induces stress on the crop as well. And this is why nurseries and greenhouses commonly put shade on this is why tomato high tunnels put shade on their tunnels during the summer months is because the shade and limiting sunlight and again, it's in the exact same range. 30 to 40% shade on a shade cloth or coverage of by paint has a dramatically yield increasing effect and a positive effect on tomato production or on flower production in Greenhouses. So this is actually, it's not a surprise. I think that many of our field crops would actually benefit from some shade during the summer months.

Interesting. Now, John, I wanted to pick your brain here a little bit, since you have me on the podcast and I have your ear for a minute, is I know very, very little about the microbiological interactions that are happening in the soil and happening between plants. And I'm curious to hear what insights you might have about the beneficial, potentially negative interactions between trees and forages. So specifically, what would you see as some of the benefits on the microbiology, in particular, of integrating trees into a pasture system that previously did not have them?

I don't know that the research has been done or I haven't encountered it. So the best answer that I can give is an informed guess. And that informed guess is simply to say that as a general rule of thumb, increased species diversity and increased diversity of different plants in a landscape almost always lends to increased microbial population diversity. And that increased microbial population diversity almost always. In fact, I can't think of a single instance where increased diversity has a negative effect or an effect on, let's say, increasing disease susceptibility. In fact, it's always the opposite. The more species diversity you have in the microbial population, the more of a disease suppressive soil you have. And disease suppressive soil is a scientifically correct terminology, and it emphasizes the disease management of the pathogen management aspect. But there is this associated benefit that when you have soils that have such vigorous microbial populations that they suppress disease, those exact same soils are also very effective at delivering nutrients to plants. And so when you think about microbial populations supplying 100% of a crop's nutritional requirements, it is these soils that are these disease suppressive soils that are the most effective at doing so. Frequently those are soils that have the benefit of having lots of species diversity of plant species above the soil surface. And so that's a very broad macro answer, I think. Obviously tree species have different microbial symbionts than the others. They're a very unique outlier. It's not quite the word that I'm looking for, but they have a very different microbial profile that they're associated with than the forbs and the forages that would be present. And so I would expect, and this is again just a guess or an assumption, but I would expect that the addition of more woody species will have a compounding beneficial effect and not an additive effect. In other words, it's a case where adding one species isn't a case of one plus one. It's a case of one plus one equaling 11 and not two. But that's just based on observational experience. And best guess, I don't have data to support a single thing that I just got done saying.

Well, I look forward to seeing the data come out in the years to come as more of these systems roll out and more people have opportunity to study them.

Yeah, we now have technology. I've been so excited to have Dr. Laura Kavanaugh join our team at Advancing Eco Agriculture because what she is bringing to the agricultural space is handheld sensors that you can take into the field or you can very easily collect samples and take them to a local center and measure the complete soil and plant microbiome and everything that is total population of all the DNA that has been identified so far, total DNA analysis, 6 million plus species in a matter of minutes for a very, very affordable cost. Like we haven't even priced this out, but I know it's going to be, I don't know, 50 to $70 neighborhood or less, perhaps significantly less.

So all of a sudden handheld in the field?

Yes.

Wow.

I say handheld would be more accurate to say pick up tailgate appropriate but small scale, miniature suitcase sized. And so yeah, it's. Once we have that technology and it's affordable and easy and anyone with a reasonable minimal level of training can measure microbiomes, we're going to have much more high fidelity data than we do at this point. So it'll be interesting to see what all that research reveals.

That sounds great. Yeah.

So anyway, coming back to. We were on the topic of the potential of shade increasing yields of the underlying forages for from both a light sensitivity and a moisture perspective and the benefits that that can have. Let's talk a bit about the species, the tree species that you perceive as having the greatest opportunity, the greatest potential impact and what that looks like from a, from a forage potential. And I'm. This is a topic that I've been interested in for years because probably over a decade ago, I forget the exact time of it, we started working with apple producers who were producing apples for processing instead of for fresh market. And that was a fascinating perspective because all of a sudden the fruit doesn't have to be perfect anymore. It doesn't have to be absolutely blemish free. And so the pesticide applications reduced it dramatically. The pruning could also be different because you didn't require perfect light penetration into the canopy and perfect fruit coloration. And they could allow the Fruit to drop to the ground and then pick it up from the ground. And the yield numbers were very different. All of a sudden you started managing pruning trees slightly differently, letting more fruit hang on the tree. The fruit can be smaller. All of a sudden we're talking about yields that range anywhere from 1200 to 1500 bushels per acre and as high as 1800 to 2000 in some exceptional instances. I started doing the math about the calorie production from a field of trees like that. And then I started looking at the math of calorie production from chestnuts and from mulberries. I started wondering, wait a minute, why are we growing grass again? Exactly. And so I'd love to get your perspective on. I know you're very passionate about honey locust because of the seasonality and the impacts that the synergies that they offer. So what are the species with the greatest forage yield potential and the greatest opportunity from your perspective?

So what I'll do is I'll break this up into a couple different categories that we commonly use. So the first category that we use is actually our trees that are there primarily for shade and primarily for quick shade. So these would be hybrid poplars, hybrid willows, black locusts. Those are our three main trees that we use in our area and they're applicable across, across a large portion of the United States. Those trees are there again for quick shade on a real budget. They're cheap trees, they are hardy, resilient, they just want to grow with our willows and our poplars in particular. What we're able to do now that we have our own nursery and we have some established stock, we're able to come into a farm with a live stake. So that's basically a branch from a tree that is 10, 12, 14ft tall. We put it in the ground 2, 3ft and then you have a 10 foot tall tree that is ready to go, it's going to make its own roots and it's going to get established that way. So very inexpensive way to get shade really fast. We're seeing where if we come in with a 12 foot tall live stake, we're able to see actual shade that is usable by the livestock in the second year, the second growing season. So those are the trees that we use for our really fast shade on a budget. And those are also the trees that we recommend to folks to start with because they're cheap, they're easy, they're forgiving. If you kill one of those, it's really no problem because they're cheap to replace. Don't start with a $40 grafted honey locust or whatever it is. Start with a $2 hybrid poplar. So that's our first category. Our second category is the trees that we use for ruminants. So mostly that is or so our long term trees for feed for ruminants. I should clarify. So mostly that's honey locust and persimmon. So honey locust is the tree that I think has the highest potential upside for ruminant silvopasture in a large chunk of the United States, because there's a couple things to its benefit. One, it's a nitrogen fixer. It has a very nice dappled canopy so that it allows a lot of light to come through the canopy and still hit the forages beneath. And then the third thing is what we already discussed is being able to drop those high energy pods. And on wild pods, you're looking at 17, 20% energy or 20% sugar, I should say. And then on more selected varieties, you're looking at 30, 35, 38% sugar in those pods. So being able to increase the amount of feed energy going into winter.

You know, one of the pieces I remember about honey locust is in the book Tree Crops. Who was the author? Russell Smith.

J. Russell Smith.

J. Russell Smith. In that book he described. This is a book of what? Written back in the early 1900s. He described the.

1927, I believe.

Yeah. He described the potential of honey locust to be grown as a sugar crop. And, you know, at 30 to 40% sugar content, something that's dropped under the ground and has minimal would be relatively easy to harvest is, I think, sugar. Sugar isn't as cheap anymore as it was a decade ago or even five years ago. And the economics of that might be worth exploring. But anyway, sorry for the digression.

The easiest thing for us is most of our systems are based on the livestock being able to harvest whatever is dropped themselves. That's the beauty of it, is the livestock will go out there and they'll pick up the pods off the ground. They'll pick up the persimmons off the ground. I will note for those people who are right now raising the question of honey locust, why in the world would I plant honey locust? Because they're familiar with the wild honey locust that has amazing and impressive and dangerous thorns on it. So anyone who's not familiar with honey locust, look it up, because they're pretty nasty thorns. They can get to a foot long or even Longer compound thorns, very sharp. Something you don't want to interact with. You don't want to have it in your pastures. Even the most zealous tree hugger would not hug these trees. Thankfully, there is a way to get those thorns out of the trees. So it's an. It's a genetic thing, largely. So there are. If you go to a farm that has honey locust, most farms, you will also see thornless honey locust on that farm. I've been to farms out in the Midwest where there's a lot of honey locusts on those farms, and I've seen trees with thorns all the way up and down on the. On the trunk, all the way up into the canopy.

You're referring to just natively.

Just native, Yep. Correct. There's been very, very little work done to improve honey locust in general over the last hundred years, except for, like, ornamental street trees. There's seedlings on those same farms that only had thorns in the branches, some that only had thorns on the trunk, and some that were completely thornless all the way up and down. And so what we're doing is we are selecting for known thornless trees and clonally propagating those trees so that what we are planting out on pastures is completely thornless. So I'll say that as a caveat for those people who rightly have questions about honey locust is we want the right trees, the right genetics to be integrating into our pasture systems. And so the other tree there is persimmons. So again, so persimmons are going to drop their fruits, and the fruit, for those who aren't familiar, is about the size of a golf ball, more or less, depending on the variety. And they'll drop their fruit anywhere from as early as August out to as late as January, February, and some will even hold on to their fruit a little bit longer. So with persimmons, we have the opportunity to really stretch our drop season over a long period of time. And we can choose varieties that drop early if we want that. And we can choose varieties that drop during the dead of winter, if that is our goal. And the nice thing is that persimmons don't have thorns on them. They don't grow very fast, which is a challenge, but they don't have thorns on them, which makes them a lot more appealing to more people or people don't have the frightening effect of honey locust. So that's the second category, is those trees for ruminants. And then if you go into a system where you have hogs and poultry, and I'll talk about hogs in particular because they can eat a lot more than poultry can. Then you're looking at mulberries.

Before we go to speaking about trees for hogs and for poultry, I'd like to just quickly follow up on what's the yield potential or what is the forage potential of persimmons and honey locust? Like how much feed value can they generate?

So I should start off with this answer by saying that there's very, very limited data on how much feed can be offset or how much livestock feed can be offset, or how much feed these trees can produce. Very limited data. And largely because it just takes a long time to set up a study like this. Most universities are not in the place where they can plant trees and then 10, 15, 20 years later run a study on the production of those trees, especially trees that are not near as popular and not for human consumption, like peaches or apples or plums or something like that.

They're not perceived as being as economically impactful for the economy as a whole.

Exactly. Yep. Livestock focused trees do not get a whole lot of attention. So with that caveat, I'm going back to the book that we referenced, J. Russell Smith's tree Crops. And in that book for persimmons in particular, he says, he talks about in Kansas being able to get four to five bushels of persimmons in a year. So if you scale that up and you plant trees on a 30 by 30 spacing and you have 48 trees, you could be looking at 200, 240 bushels of persimmons per year. Now, if we want to compare those to corn, because corn is a useful comparison that a lot of people understand, you'd have to adjust for the moisture in the corn and the moisture in the persimmons, which is going to be higher than the moisture in the corn. So it brings your numbers down to roughly equivalent of 100 bushels of corn equivalent per acre coming off of your persimmon trees. And this would be very low input system.

Practically none. Really?

Practically no input.

But then, yeah, there is also the key aspect we don't want to lose sight of is that the livestock can pick them up off the ground at a time of the year when they really need the energy and can benefit from that.

Exactly. So your labor inputs, your financial inputs into this system are absolutely minimal. And you're able to at the same time produce a full crop of forages underneath those trees.

Yeah. How about for Honey locust.

So on honey locust, there is probably even less research done on those. But there was a study done in the 1940s, the very early 40s, and unfortunately it was cut off, like a lot of tree crops research because of World War II. But at the age of 7 to 10 years old, if we look at the yield over that time period for these grafted honey locust trees, they were averaging a yield of about 95 pounds of pods. And this is dry matter. So 95 pounds of dry matter per year over that time frame. So 95 pounds for trees that were 7 to 10 years old. So not old trees at all. They were well taken care of. So if you have a density of here in my paper I wrote 36 trees per acre, you're looking at £3,420 of pods annually coming off of that acre for honey locust.

Wow. And given the energy content, if you're talking 30 to 40% sugar content, that is a lot of calories per acre. That's a significant energy yield.

Yes, indeed. Yep, yep. So that's, that's why I'm optimistic about the, the, the upside of, of silvopasture and its broad applicability.

All right, so you were about to move on to speaking about trees for hogs and poultry. Tell us about what the opportunities are there.

So there. If you're raising hogs or poultry, most people even raising, let's say pastured pigs, most of their diet is still going to be coming from imported or from grain. Right. Feed that is brought onto the farm. And so we have a real opportunity to reduce our feed costs. And given that these are monogastrics, they are not ruminants, so they are not meant to have their full feed coming off of forages. They can supplement with forages. But in the wild, our wild boar are not grazing on grasslands. Our chickens are not domesticated from prairie chickens, they're domesticated from jungle fowl. This is the habitat that they want to be in. This is what creates a low stress environment for them. Hogs do much better. Poultry do much better when they are not heat stressed. So there's a lot of reasons to integrate trees in general, and then we might as well integrate trees that are going to provide additional feedback. So mulberry is one that we look to for both hogs and poultry. And mulberry is really nice because it is easy to propagate, it is inexpensive, it grows really fast, it transplants well, and it'll start to yield, it'll start to yield Immediately, like once you graft a mulberry, it wants to set fruit that very first year. So in terms of a quick return on investment for tree planting, mulberry is really hard to beat. And then not only does it drop high quality, high energy fruit, but the leaves of a mulberry plant are also very digestible and very high in protein, similar protein content as clovers and similar digestibility as well. So digestible that even humans can eat it. So in certain cultures, mulberry leaves are used similar to like a grape leaf when you have a, when you wrap rice or something like that in a grape leaf. You can do the same thing with mulberry leaves. So very multifunctional tree for use with hogs and with poultry. And then hogs can eat just about anything. So acorns, chestnuts, beech, nuts, apples, pears, plums, just the whole gamut that they can consume and make good use of on the farm.

And when I stop to think about it, I'm actually curious. There's two questions that come to mind. But why not apples and chestnuts for ruminants? Why did you exclude those from the list?

Yeah, so. And we might integrate more of those in the years to come. The challenge with apples in particular, and this applies to other fruits that are fairly, that are perishable, more perishable and drop during the warmer seasons of the year, is that if you're in a system where you're rotationally grazing and you're not coming back through for a 30, 40, 50 days, whatever it is, if a fruit falls and your livestock aren't through in the next five days for a mulberry in the summer, or maybe it's 10, 20 days for apples in September, October, the feed value, you're losing a large chunk of that feed value. So that's the, that's the complexity of integrating some of those trees into a ruminant system with long rotational grazing cycles. Now, you could set it up in such a way that you would have, let's say, a paddock that the cattle can regularly go to, but then they would need to regularly go to that paddock over the course of the drop season. So we haven't yet designed some of those systems. You could, but then there would be some downsides to them as well. The nice thing about honey locust is once they drop, they drop in November, December, and those pods are going to be there until livestock come back around.

Well, let's talk about this for a bit. Let's talk about chestnuts first. Wouldn't the Same be true for chestnuts, that they would drop and remain stable on the ground for an extended period.

They would probably stay better than apples. I'm sure that they would stay better than apples, but less than honey locust. What I've seen so far with suggest that chestnut yields are going to be lower than honey locusts. I've heard from various growers anywhere from a range of £1,000 per acre to £4,000 per acre, depending on the site conditions and whatnot. And then when you adjust for moisture. So that would be. That would be a fresh weight. And I think chestnuts are about 40 or 50% moisture, if I remember correctly off the top of my head.

Yeah. The downside, of course, you also have the burrs to deal with as well, which is never particularly fun. But I'm actually. Well, I have limited experience. But the experience, limited experience that I do have suggests that anyone that's producing less than a minimum two or three thousand pounds per acre of chestnuts on relatively young trees needs to get on the AEA program because there's lots of opportunity left on that table.

Sounds good. And I look forward to seeing as we get to that point where we are. We've figured out some of these basic things of how to get trees established. I'm looking forward to seeing how can we make these systems really sing and really produce.

Yeah, those really 6,000 or 8,000 pounds per acre of chestnuts is not. Is not a difficult stretch. Now, of course, I'm also. I need to offer the caveat that I'm thinking of that in terms of chestnut production, not in terms of silvopasture. And so there is some. There will be a reduction there proportionally.

Yeah. Most of our systems are going to be low input. Low input where the trees are more or less secondary rather than a primary production interest to our growers.

I'm also talking about low input, but I'm not talking about no input like it's. You can do some very minimal levels of management that will make some significant differences. But let's talk about apples because there is something that many people don't know about apples. First of all, as I'm sure you're aware, apples have this tremendous genetic variability and genetic diversity. And one of the characteristics of some strains of apples that can be selected for is that you can actually select apples to be held onto the tree and to drop at different times of the year, just as with persimmons. And there are folks who have done some very innovative selection and breeding work who have apples that are being held on the tree all the way into the middle of the winter, January and February, before they drop.