How Soil Health Impacts Performance of Cherry Varieties with Professor Lynn Long

Hi friends, I'm John Kemp. Hosting this podcast. I am passionate about developing regenerative agriculture systems that improve soil health, produce crops that are completely resistant to diseases and insects, and produce fruit of such an exceptional quality that we can have a legitimate conversation about growing food as medicine. I've discovered that there are many people with incredible knowledge and information about soil and plant systems and how to develop regenerative agriculture systems. However, much of this knowledge and this information is scattered. It's found all over the place, some of it has been published in peer reviewed publications, but there are many incredible stories and a lot of knowledge that has not been published and that hasn't been shared with many people. I started Advancing eco Agriculture in 2006 to bring this knowledge together in a more coherent fashion and incorporate it into products and growing systems that growers can easily put into practice. It's my personal mission to have these regenerative agricultural systems become adopted globally and become the mainstream, the status quo against which all other growing systems are compared. To help achieve this goal, I want to share the knowledge that we have learned in the last decade and make it available to everyone while we have developed products at AEA that embody the principles of regenerative agriculture systems and make them easier for growers to apply this knowledge and these principles can be applied anywhere and when they are applied properly, they will always increase farm profitability and resilience to climate stress. If you have any questions, suggestions, comments or ideas, topics that you would like for me to discuss, Please connect on LinkedIn or on Twitter where my username is visionbuilder7 or you can also email me at john kempf.com I would very much like to hear from you and to hear your feedback. Be sure to subscribe to this podcast and thank you very much for listening. Enjoy the show.

Greetings friends and welcome to the Regenerative Agriculture Podcast. On this podcast we explore the science and practical application of regenerative agriculture ecosystems and talk about how to regenerate soil and crop health and quality and how to increase farm profitability. In this episode, I'm very excited to welcome Dr. Lynn Long to our show. Lynn is extremely well known in the sweet cherry industry where he has worked for several decades in evaluating varieties, looking at different rootstock, looking at different pruning systems, and has done some exceptional work in the space. Lynn, we're very excited to have you with us.

Thank you. I appreciate the chance to be here.

Lynn, you have done some exceptional work over the decades working with sweet cherries. What are some of the memorable moments and the highlights that led you to where you are today.

Well, I think I'd have to go back to the early 1990s. At that time, for those people that were in the sweet cherry industry, you know that most of the production in the United States was focused on one single sweet cherry variety. And that variety, of course, was Bing. And we grew our cherries on one rootstock, and that rootstock was mazard.

And.

And we used one training system, which was kind of a open base. We were starting to transition into a training system that was developed by growers up in Washington State that was called a steepleader system. But, you know, there wasn't a lot of diversity in the free cherry industry at that time. And in 1994, the cherry growers in the mid Columbia area of Oregon, I worked for Oregon State University, got together and sent me on a fact finding mission to Europe. And what I saw over there changed the way that we farm cherries here in the United States. And so I think that probably was the one thing that has transformed my work in the sweet cherry industry more than anything else and has transformed the industry here in the United States more than anything else.

What was the shift that happened? How did you begin managing trees differently?

Well, so it was interesting. So back in the 1970s, I started working for Oregon State University in 1988, 30 years ago. And prior to my starting my tenure with osu, we were in the experiment stations at Oregon State University and Washington State University. We were testing new cherry rootstocks. And so we were looking at some of them that had been developed in Europe, a series that was developed in Oregon, but nobody was thinking about moving that from the experimental stage into the commercial stage. Same thing was true for varieties, although with varieties, nobody was even looking at other options. We had Bing for Blush variety, we had Rainier, and basically that was it. Nobody was looking any further than that. And the problem was that if something happened to destroy your Bing crop the day before you were going to pick it, your entire income for that year was wiped out. If you had rain, for example, the day or a week before you were going to pick the crop, you know, you lost. You lost your crop and you moved on to the next year. And so there was good reasons for us to be looking at other varieties, but nobody was thinking about at that time. And when I went to Europe, what I saw was that growers in Germany, for example, were using dwarfing rootstocks commercially. Growers in France were talking about the pedestrian orchards, orchards that can be harvested from the ground without the use of ladders. And our trees were, you know, 20, 25ft tall, using big ladders to harvest our cherries. And they were using in places like Germany and Spain and France and Italy, they were using multiple varieties to harvest their cherries early, mid season and late, which also protected them from events like rain because the cherries may be more resistant to rain cracking, some varieties more resistant than other varieties. Plus, if you get a rain early, your late season varieties are still pickable. And so when I came back and started talking to growers about some of these things and doing some research on these things, the training systems, varieties of rootstocks, then all of a sudden the growers understood the need to move forward. And starting in the late 90s, there were some dramatic changes that happened in the cherry industry with all three of these areas.

When you think about each of these three areas, obviously they're an entire cultural management system that tie together. You have to use all three of these pieces together. One of the areas that I know many growers are becoming much more interested today is understanding how to manage plant health with these newer systems. In some parts of the country, I've heard the conversation that many of the newer genetics and newer varieties, particularly some of the dwarf rootstocks, don't seem to have the root vigor and strength and the capacity to absorb nutrients from the soil profile. I've not seen. We have, we've observed some differences in various varieties being able to pick up nutrients more effectively than others, but they've been fairly slight. But I've never been able to compare with some of the older rootstocks. How do you feel the vigor of the modern dwarf rootstocks compared to the vigor of some of the older varieties that were available?

Yeah, well, some of the. One of the reasons why some of our growers still prefer the older rootstock, such as Mazard, which is a kind of a default rootstock here in the Pacific Northwest for cherry growers, and has been for years and years, is because it's a rootstock that establishes itself well. It grows deep into the ground, so it pulls in nutrients from a wide ranging area, and it grows a vigorous tree that fills the space quite quickly. So some of the, some of the dwarfing rootstocks, there's a series out of Germany called the geeselisaries, produce dwarfing or semi dwarfing trees, and their rootstocks are also a lot more shallow. So you've got to be sure that the nutrients are delivered to the root zone for uptake by the tree. You no longer have that huge bank of soil and nutrients that the cherry tree can naturally find by itself. And so you have to be thinking about these things a little bit more. You have to be thinking about delivering the nutrients to where the tree is, whether you're doing it through drip irrigation or a micro sprinter system, because the tree is not going to be able to send its roots down to an area that can find all the nutrients it might be able to, that it might need in order to remain strong and healthy.

Earlier you and I spoke a little bit about looking at the other half of the tree. What do you think has been missing in perhaps with varieties and genetic selection and also cultural management in terms of looking at the upper half of the tree and not at what's happening below the soil system?

Yeah, so I think that this is one of the key areas that I think we're going to be moving in the future because up till now we have been focusing our attention and our research and growers have been focusing their most of their management on just half of the tree, just from the ground up. And you know, when we talk about a cherry tree or talk about any type of a tree, what we're really talking about, at least what most people are thinking about is what they can see. But there's a whole world of what's happening under the soil that we don't think about, that we are not actively managing and we are not actively doing research on. Now, there are some exceptions to that. And I think that we're seeing more and more scientists doing research on that part of the tree that is below ground. What's happening below ground? What are the micronutrients that are supporting the growth of the tree? What are the microbes and the fauna that is going through its entire life cycle underneath the soil that is causing the tree to either be healthy or not to be healthy. And I think that growers too are starting to think about this more as a whole system rather than just half a system, as we've been looking at this for decades and even centuries. I think that's a really positive thing that is happening now, that more and more growers are thinking about the entire tree and more and more scientists are thinking about the entire tree and not just the above ground portion of the tree.

Yeah, when you think about hormonal interactions and nutrient transport, nutrient absorption, et cetera, there's the root system plays a major part in the reproductive potential and other pieces that are happening within the tree canopy.

What are some of the things that.

You'Ve observed that caused that. You started thinking about managing what's happening in the soil profile.

Well, when we are using these dwarfing rootstocks, a lot of them are fairly shallowly rooted. And so where you have a situation like what we have here in the Pacific Northwest, we have a Mediterranean climate. The summers are very hot. Our cherry industry in both Oregon and Washington is on the east side of the Cascade Mountain range, which is a more or less a desert to semi desert location. And if you go out into an orchard in July, August, maybe even June, and you try to put a soil probe into the soil, it's like concrete. You can hardly get that soil probe to penetrate into that soil. And when you have dwarfing rootstocks and those roots are so shallow in the soil, you've got this soil that is so hard and impenetrable, that's got to be affecting the growth and behavior of the tree. Plus we see that a couple of these rootstocks, Geesla 5 and Giesla 6, a couple of these German rootstocks that I was mentioning earlier, when the temperatures get really hot, when you get temperatures like 100 degrees or more, which happens several times a year in this climate, the leaves look stressed, they look wilted, and again, that's got to be affecting the quality of the fruit. The tree is going to try to protect itself. And so it will take moisture from wherever it can find it. If it can't bring it up from the root zone in order to the counter the translocation that's taking place from the leaves, it's going to take it from the fruit. And that's got to affect fruit quality. So from there I got to thinking about, you know, there's got to be some way that we can protect this soil from the heat and from the drying that takes place in the middle of the summer. Maybe we should be thinking about mulches. Then we thought that kind of developed into looking at compost and compost mixtures. And from there, there's a lot that we don't know yet. But from there we started realizing that if we can keep the soil friable and moist at the surface, then there's a possibility that we can keep the microorganisms alive in that level of soil throughout the entire year. And by doing that, that's got to affect the health of the entire ecosystem, including the health of the tree. And so that's kind of, you know, my thought processes over the last few years, as we've been thinking about not only what's happening above Ground, but also in the entire ecosystem of the, of the tree.

What have you learned so far with the emulsion and compost trials? What has, what has stood out for you?

Right now we are in the middle of a multi year study and we're just at the beginning process of that, of that study. So scientific data I can't share with you, but we certainly have some observations where we have seen some orchards that have been struggling have turned around, leaves that were small and chlorotic have started to grow larger leaves, better color. And what's causing that, what's having that positive effect, we don't know yet. I think that we are being successful at keeping the microorganisms alive throughout the season, the summer season as well as through the rest of the year. We're taking some of the stress out of the tree by keeping the soil cooler. And so I think it's just a whole positive change that is being made to the entire ecosystem of the tree and not just relying on the moisture that we've been giving them through the irrigation system, through the fertilizer that we've been applying to them. But now we're looking at, okay, how do we add organic matter to the soil by using some of these organic mulches, organic compost, how does that affect the overall health of our trees? Those are some of the questions that we have yet to answer. And like I mentioned earlier, plantas are just beginning to, to look at some of these questions and get answers for them. But I'm happy to see that more and more scientists are finally asking these questions.

Yeah, I think it's certainly interesting. In a recent discussion, a microbiologist made the point that in her estimation, we know less than 5% of what is going on in the soil underneath our feet. And I certainly respect that viewpoint that it's, that's something that we don't understand very well and we don't understand the full implications of how biology interact with plant roots and how they might have the capacity to affect the crop that we're growing.

Yeah, that's exactly right. I just returned from a trip to Chile on Sunday a couple days ago. I've been working with some growers down there and encouraging them to use compost and mulches and, and last year in Chile they had a very heavy cherry crop to the point where some trees weren't harvested, some blocks weren't harvested because the cherries were just overset and they were too small. But I've been working with one grower down there who I encouraged to put on some compost and mulches. And he attributed the vigor in his trees that I saw there now, but you got to remember that they harvest their cherries in December and January, so now they're just going into the fall. So I was looking at trees that were. That were dormant, that were dropping their leaves or had dropped their leaves. And yet in some of these trees that typically you would not have expected to see any growth because the fruit load was so heavy in the tree, they had nice, long, vigorous shoots. And he attributed that to the fact that he had been using compost and mulch through the year, and that made that kind of difference. Now, whether or not that was true or not, I can't say. I don't have any data to back that up. But I'm just relaying to you the observations and the comments that the grower.

Made to me that's intriguing, and that would correlate with some of the things we've observed in other orchards that we've worked with. In the work that you have done or the operations that you have observed. I guess perhaps I'll just say in your life experience, what has been something that surprised you?

Well, I think that one of the things that has surprised me, and yet I appreciate very much about the grower community, is that wherever I travel in the world, cherry growers are willing to share ideas with each other. Occasionally, you find somebody who, you know, doesn't want to. Thinks that they have all the secrets and they don't want to. I don't want to share those secrets with anybody else. But for the most part, wherever I've traveled in the world, growers have been willing to share ideas and share what they're doing with other growers, with scientists. And I think that's just a really nice thing about this industry. We have growers from all over the world that come here, and our growers are willing to invite them into their orchard and show them around, show them new ideas and techniques that they're working on. And, you know, that's just. That's just really nice to be a part of that type of industry that is open and is willing to share ideas, but also receive ideas from other people. And I think that's one of the reasons why the cherry industry has advanced so much in the last 20 years.

I think you just identified a very key piece when what we have observed and what I've observed around the countryside is the growers who are the most willing to share ideas are also the same growers. I guess perhaps the Simplest way to say it is that you receive in the same measure that you give. You share ideas and share information with other growers. Almost invariably, you learn things that can help you on your operation as well. And I would agree with you that that is something that is very pronounced in the agriculture space in general and very valuable. Yeah.

And I think that the. I guess I would encourage growers, professionals that are listening to this. I think the more traveling you can do to see what's happening around the world. And I started off by talking about how that one trip to Europe back in 1994 changed an entire industry in the northwest and really throughout the entire country. And since then, there's been a lot of our growers that have gone to other parts of the world, and a lot of growers from places like Australia and Chile and Argentina. Argentina and even from Europe that have come here and just looked at what we're doing, and we look at what they're doing. And the grower community is really a very hospitable community. And I've seen it where they've, you know, they've invited people to come. They've had barbecues for people. They share ideas. And really, it's the same with a scientific community as well. I'll go up to Canada and visit research stations up there. They'll come down here or go to. I'll go to Germany or I'll go to Australia and visit with their scientists, and they come here and visit with us. And this is how we advance. This is how we move forward, and we learn from each other. We learn what doesn't work. We learn what they're doing that has worked. We put that together with our ideas, and with that, then we advance. And I think that's the only way that we advance.

Exactly. One of the pieces that I've observed, which I find really intriguing, is everyone has a unique perspective on the work.

That they're doing and the things that.

Are happening in the world around them. And along those lines, one of the.

Questions that I'd have for you is.

What is something that you believe to be true about modern agriculture that is perhaps a different perspective from the mainstream?

I think that probably the most important thing we've already talked about, I think the mainstream agriculture has focused on, as we mentioned, just half of the tree, half of the plant. And I think that what is true is that there is a lot more that's going on out there than what we realize. What that is, we're just starting to learn. But there is much more happening below the soil surface than we've ever thought of before, we've ever realized before. It's great to, you know, talk about pruning this tree, about how we train the tree and all that, about the irrigation needs of the tree, about the fertilizer needs of the tree, about putting on foliar fertilizers, whatever that might be. But there is so much more to growing the tree than we have understood up to now. And there's a whole world out there of science that we're just beginning to penetrate. I think that if we look forward in the next 20 years, I think that the changes from now, next 20 years are going to be just as dramatic as the changes that happened in the cherry industry back in the mid-90s to what is what we're looking at now. But it's going to be in a different area. It's going to be from the ground down and not from the ground up like we focused on previously.

Those are some fascinating and intriguing comments. I guess the one question that comes to mind immediately is how do you think if we manage what is happening below the soil differently, how might that influence or change the way we manage what is happening above the soil?

I think it might change things dramatically, significantly. You know, I think that there may be issues that we are struggling with now that may become minor issues in the future. And what I'm thinking of is if you've ever grown any prunus species, trees like cherries, you know that bacterial canker is one of the banes of the cherry industry. One of the reasons why the cherry industry in the United States is located on the Pacific coast or Washington, Oregon and California is because we have dry summers. And bacterial canker is a disease that comes in and infects trees and can kill entire branches and eventually entire trees by girdling off the above ground portion of the branch or the trunk. And really there is no good cure. It's a. It's a disease that affects cherry trees, peach trees, apricot trees, all the prunus species around the world. So if you go to Chile, they're struggling with the same thing. You come to go to California, they're struggling with it. You come to Oregon, that we struggle with here. And especially where it is where they have a lot more rain in the summertime, that's where we have problems with bacterial canker. But I think that by getting the microorganisms to work for us to keep the tree stronger and healthier, I think that that is going to be in the future. One of the things that helps us to solve this problem that we have been struggling with for centuries. And in the future, we may not have such issues as bacterial cancer, at least not as severely as what we've had to deal with in recent history. Where, for example, in the Hood River Valley of Oregon, which is a little bit wetter climate than what we have in the Dalles where I live and work, we've lost up to 60% of some trees in orchards because of this single disease. But if we can get the microorganisms in the soil to work for us, keep those trees healthier. This is all speculation at this point in time, but it's something to think about that this again may change the entire industry.

Yeah, well, actually, I have a follow up question to that, but before I go there, one of the pieces that I have wondered is as the root system begins changing, if we develop a much, perhaps I'll say a much more aggressive root system and a root system that is colonized by plant growth, promoting rhizobacteria, beneficial fungi and bacteria, etc. How might that change the way the canopy expresses itself? Is there a possibility we might get.

A lot more growth?

Is there a possibility we might need to consider adapting pruning and canopy management practices and so forth? Do you have any thoughts or ideas around that?

Yeah, I think that anytime you have a healthy root system that is exploring a wider area, it means that the nutrients that that tree needs are more readily available, that the moisture that that tree needs is more readily available, even in times when we have 100 degree weather where that keysless six rootstock tree is stressed. Now, if the rootstocks are growing more vigorously because of a healthier ecosystem, then it's going to help keep that tree from being stressed. It also means that there's going to be more vigor in that tree in a situation where the soil is marginal. It may mean that we can now grow healthy trees in that soil that can produce high quality fruit. We weren't able to do that before. It might also mean that you're right that we may have to adapt our training systems, our pruning methods, or maybe we would develop new rootstock. There's a new series rootstock series coming out that will be available very soon from Michigan State University called the Caretaker series. And this is a series of rootstocks that's even more dwarfing than what we are currently using here in the Northwest. And rootstocks like these may be the future of the cherry industry. If we can get the roots to establish well, to grow, to be healthy. And that will also cause the tree to be healthy and to grow as well. I always tell growers that I like to see at least 2ft of growth on all of the new shoots throughout the entire tree. So at the bottom of the tree, at the top of the tree, it's easy to do that in the top of the tree, but down at the bottom of the tree it can be difficult sometimes. But if we have that root system working for us because the microorganisms are working for us, then we're more able to get that shoot growth that we need throughout the entire tree and get high quality fruit throughout the entire tree, not just on the top of the tree.

One of the pieces that we've observed is that as nutrition management practices change, growers are able to get that consistent growth, but also to get very high quality growth with tight internode spacing. And I think there are many ways that nutrition and biology and genetics, they all tie together and they need to be managed. You mentioned the key word several times, which is we're really managing an entire ecosystem. We can't just manage one aspect of it, we have to manage the entire ecosystem.

Yeah, that's exactly right. Yeah. We need to be looking at.