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Field results of nutrition management on freeze resistance, bacterial canker and powdery mildew in cherries

From the podcast interview with Mike Omeg:

John: Mike, you’ve been talking about the returns in very abstract terminology of return on investment, etc. Tell us about results. What has changed with your trees? We started this conversation by mentioning a desire to develop the root systems. What has changed with your root systems? What has changed with tree health? What have you actually observed in the field?

Mike: I have some anecdotes and then I have some actual data to share. Let’s start with the anecdotes.

In November of 2014, we had one of those once-in-a-lifetime historic freezes. The lowest the temperature had been was 43 degrees. Our trees generally go into dormancy in November, but it had been a very warm fall and the trees were still actively growing. We hadn’t had any acclimation to the cold. Then we had an arctic front come down, and we went from lows in the 40s to below zero in one day, and it stayed below zero. Here at my house, we had -4 degrees Fahrenheit.

The leaves on the trees just turned black. Just like a dahlia plant looks after the first frost, the leaves turned black, and they just hung on the trees. Several hundred acres of trees in our area just died. We had blocks where all the buds were frozen on the trees.

At that time, I was doing some comparison and analysis between mulch and intensive bionutrient applications and conventional applications for management of the orchard. I had two orchards that were sitting within a quarter-mile of each other at the same elevation. One was on one side of a small canyon and one was on the other. They were the same age and variety of trees and had the same irrigation. The only difference between them was the nutrition management. One had received compost mulch and bio-intensive nutrition, and the other orchard was just a standard conventional orchard.

After that freeze, all the trees in the conventional orchard were dead. They froze and the entire canopy was killed. We could have regrown them from the roots, but the trees were dead down to the soil. The entire orchard was smoked. There wasn’t one tree left. When you went and cut bark, it was black underneath instead of bright green. I had to remove that orchard the following spring

The orchard where we’d been following these bio-intensive practices, believe it or not, had 110 percent of a normal crop that year. We actually picked 10 percent more fruit out of that orchard than we did the previous year. That truly amazed me. That difference was only due to the nutrition management and these other activities that we were doing. There was no other difference.

The other thing that we’ve observed over time is a marked reduction in two pathogens that are problems for us with cherries. One of them is bacterial canker. Bacterial canker causes cherry trees to eventually die. They create a lot of gum. The trees get a canker that has a swelling of sap under the bark, and then these cankers burst, almost like a blister, and sap oozes out of them. That disease is a particular challenge with certain varieties and certain rootstocks of trees. If it doesn’t wipe the orchard out, it takes enough trees out that you lose the value of that block as an economic unit.

The consultants at Advancing Eco Agriculture I work with started to tell me that we should try to take on bacterial canker by focusing on nutrition. Over time we had an amazing transformation in a block that had significant amounts of bacterial canker—enough that I was going to take the block out. But I left it there because I didn’t have anything to lose.

Bacterial canker was actually eliminated from that block. It wasn’t just reduced—it was actually eliminated. Virtually all of the trees in that block had one or more canker sites on them. Some were far worse than others, but almost every tree had at least one canker on it. By the third or fourth year, we could not find bacterial canker in that block. I had neighbors coming to the block. I had extension staff and research pathologists from Oregon State coming to that block, and they could not believe the change.

The second disease that is more problematic in cherries is powdery mildew. That disease affects the foliage and fruit. It’s a real challenge. Powdery mildew is the disease that is targeted by almost all the fungicide applications that are applied in conventional and organic production of cherries. What we’ve seen is that highly susceptible varieties normally would require extra powdery mildew applications. But we’ve been able to reduce our applications by half, and maybe I could reduce them by more—I’m just a bit nervous about reducing them by more. But we have been able to apply half the number of fungicides to those trees, and we have no mildew there.

This is another thing that neighbors couldn’t believe, so we actually had a walking tour through that block. One of them was hosted by extension. I made a bet with the neighbors—I said, “Find any mildew in this block and I’ll buy you a steak dinner.” I’ve never had to buy a steak dinner because folks can’t find mildew in that orchard. A typical orchard with that variety in it would have lots of mildew because even with fungicide applications we are not able to control it.

Those are two things that that we’ve observed that I honestly thought would never happen. Through nutrition, we’re able to manage our diseases—in this case, with bacterial canker, and with powdery mildew. It speaks to the long-term value to the orchard of providing the nutrition that the tree needs. Do that and the tree will take care of itself.

P.S. I am hosting a Zoom video AskMeAnything discussion on Friday at 1 PM EDT. You don’t need to register in advance, just connect here at 1 PM.  See you there!

Healthy mosquitos don’t vector malaria

When we think about epigenetics and the phrase “environment determines genetic expression”, we should think about what this means not just for the plants and species we are trying to optimize, but also for all the plants, fungus, bacteria, nematodes, and mites commonly called ‘pests’. If environment determines their genetic expression, that means we can manage their virulence or pathogenicity to the degree we can manage the environmental factors they depend on.

Tom Dykstra shares an interesting perspective on healthy vs unhealthy mosquitos, and their capacity to resist infection from malaria or other ‘pathogens’.

John: You and I have discussed before how environment determines genetic expression. And you expressed that you have had difficulties infecting some mosquitoes with malaria. As we’ve been having this conversation about mosquitoes, that popped back into my mind. What are the differences between healthy and unhealthy mosquitoes as vectors of infectious disease?

Tom: Well, I personally have not infected mosquitoes with malaria, but I’ve talked to researchers who’ve worked on this. Let me put it this way. Most Anopheles mosquitoes do not transmit malaria. Most Aedes mosquitoes do not transmit dengue, yellow fever, or Zika. Most Culex mosquitoes do not transmit encephalitis.

When you observe this, you understand that not all insects are infected with the disease. So you can get bitten by thousands and thousands of Anopheles mosquitoes and not get malaria. But all you have to do is be bitten by one mosquito that does have malaria in order for you to get it.

And this is one of the truths of biology that has been revealed to us—that insects also have various states of health and lack of health. In order for them to be relatively healthy, they need digested components. Their food sources need to be as such. But if their food source is not that good, or if it’s missing something, they can suffer. Insects have died in the field. I’ve seen it many times. Sometimes people try to keep them as pets and they die. We see them dying in the field all the time. They are susceptible to disease. They also have states of health and lack of health that are somewhat analogous to what you would find in a human.

If you’re working with mosquitoes in the laboratory, and you try and infect them with the particular disease that they’re supposed to be infected with—Anopheles mosquitoes with malaria, for example—you will not get a 100 percent infection rate. And that is amazing. This is in part because when you’re raising them in the laboratory, they’re coddled. They’re given everything they need. Therefore, they’re in pretty good shape, and it becomes a little difficult to infect them. Out in the field, they might be more susceptible. Ones that are more susceptible might die. Others would be more susceptible to actually getting a disease—like the malaria protozoan or the Zika virus or anything of that sort. And it can actually take hold of the system, because the insect doesn’t have the immune system to take care of it. It kind of sets up shop inside the insect. 

2020-07-27T19:35:50-05:00July 28th, 2020|Tags: , |

The impact of soil carbon to nitrogen ratios on disease suppression

A foundational goal of regenerative agriculture management practices is to increase the volume of carbon that is cycled through soil systems. Not just statically stored in soils, but cycled through. The more volume of carbon that is cycled, the more robust the soil microbial community becomes, the more efficient plant photosynthesis becomes, and the better the entire ecosystem functions.

When more carbon is cycled in different forms, microbial balance and activity shifts to match, which results in changing the quantity of nitrogen that is sequestered, and the quantity of phosphorus, sulfur, silicon, and trace minerals that are released from the soil mineral matrix.

When abundant carbon is cycled, soil biology has the food sources required to fix all the nitrogen they require from the atmosphere, and no additional N needs to be added. This also results in a change of the dominant direction of N mineralization to be primarily nitrate or ammonium, which influences disease suppression and crop nitrogen sufficiency.

Here are some important thoughts on this topic Don Huber shared:

John: What is the impact of carbon-to-nitrogen ratios on both disease-suppressive soils and also on yield?

Don: The carbon-to-nitrogen ratio depends on the carbon source.

That got me in trouble with my first publication in plant pathology. I challenged the carbon-nitrogen ratio hypothesis. People were saying, “If you have a 12:1 versus a 40:1 ratio, you’ll always have a disease relationship.” And I demonstrated that it’s not the carbon-to-nitrogen ratio. It’s the form of nitrogen that is involved in that ratio.

You can take different crop residues or a different cropping sequence, and it’s the effect of that sequence on the form of nitrogen that determines what the disease reaction is. And, of course, the effect of that form of nitrogen quite often is an effect on manganese or zinc or copper or other nutrients, along with the form of nitrogen.

Carbon-nitrogen ratios work if you’re working with the same nutrient source or crop residue and then varying the nitrogen ratios by either harvesting plants when they’re greener or harvesting plants drier—when you have wider carbon-nitrogen ratios. But the carbon-nitrogen ratio per se isn’t the factor that’s involved there. It’s the effect of that ratio on the form of nitrogen and the other minerals that are involved—such as manganese or zinc or iron or copper—that are critical for particular physiological processes.

P.S. I had an interesting discussion with Koen van Seijen on the Investing in Regenerative Agriculture podcast that just released. Much of our discussion revolved around the question, “How would I invest a billion dollars in accelerating the adoption of regenerative ag?” You can find it here.

Unhealthy people attract mosquitos, just like unhealthy plants attract other insects

Insects will only eat that which is digestible to their system.

From the interview with Tom Dykstra:

John: I have friends who will attract every mosquito for dozens of yards around, and others who, for all practical purposes, are mosquito-immune. Can you describe the differences?

Tom: I hate saying this, but that is the difference between healthy people and unhealthy people. If you have digestible blood, the insect can use your blood. If you have healthy blood, the insect is not attracted to it. Does this mean you’re healthy all the time? No. People have certain states of healthiness and unhealthiness. But as long as your blood is digestible, it’s going to be attractive to an insect.

It’s the digestive system. Insects do not have very good digestive systems. Stuff has to come in digested to them because they cannot digest things. They just don’t have the enzymes. They’re garbage collectors. They eat muck. They eat garbage. They eat bad stuff. They eat stuff that we don’t want to eat. Take a look at cockroaches, for example, or fruit flies. They’re always around decaying fruit. They’re not around healthy fruit. These insects that are keying in on very specific plants. Or even, let’s say, the fruiting structures of a tomato—that’s what they are keying in on.

Mosquitoes need something that’s digestible. When they take a blood meal, it must be incorporated through the process of vitellogenesis: taking those nutrients in your blood and incorporating them into an egg. This occurs in about twenty-four hours—very, very quickly. So if they’re not getting digestible blood, they cannot, through the process of vitellogenesis, take those nutrients and feed their eggs. And that’s a problem, because obviously the mosquito wants to feed its egg. The only reason it takes a blood meal is to feed its eggs.

We do have these differences among individuals. Some are just more digestible than others, and they’re going to be more attractive. Grasshoppers have a choice as to what crop they eat, and mosquitoes have a choice as to what blood meal they wish to get. Through their antenna and all of their senses, they detect that someone is more digestible than another, and they’re going to go after that individual. Even though that may offend some people, I do feel an obligation to tell the truth the way that I know it, according to the information that has been given to me for the past twenty to thirty years of my life studying insects.

John: I very much doubt that you’re offending people. I would say that you’re simply communicating some very intriguing ideas that many of us have observed to be true in real life and have wondered about the differences. So thank you for sharing that.

Tom: I’m happy to do so. When you go to the supermarket and you see fruit flies flying around the tomatoes, some people think, “Oh, I don’t want these tomatoes—they have fruit flies in them.” But honestly, all you have to do is find that one tomato near the bottom that’s injured, and that’s where all the fruit flies are located—near the one that’s unhealthy. And that essentially equates to that which is digestible. A tomato that is degrading—that is decomposing—is being broken down. And when it’s being broken down, it’s digestible. Insects will only eat that which is digestible to their system.

2020-06-23T14:38:59-05:00July 2nd, 2020|Tags: , , |

Nutritional integrity is needed to increase photosynthesis

We know it is possible to increase the quantity of sugars produced in each 24 hour photoperiod as much as three to four times higher than the baseline of what is considered ‘normal’ or common in most crops today. In addition, it is also possible to increase the ‘quality’ or the complexity of carbohydrates produced in each photoperiod. Plants with limited nutritional integrity produce lower volumes of simple sugars. Healthy plants produce much larger volumes of more complex sugars.

When the plant begins producing larger volumes of more complex sugars, the crop begins behaving differently. There isn’t a good way to describe this. Internode lengths become shorter, while growth is faster. Clusters of fruit or heads of grain have more kernels or fruit, and mature earlier. Very importantly, the crop begins contributing more carbon to the soil than it removes, even when 100% of the above ground biomass is removed.

Here are some thoughts Don Huber shared when I asked him about photosynthesis during our first podcast interview.

John: Don, one of the things I believe is quite important that we haven’t spoken about is the general impact of photosynthesis and the quality of photosynthesis—how photosynthesis can vary in crops and cover crops and how that influences the volume of root exudates. How can a grower increase the quantity of photosynthesis and increase the quantity of root exudates in the soil profile?

Don: You’re not going to have any photosynthesis if you don’t have manganese. Manganese is critical for splitting water; it provides the hydrogen that can then combine with carbon dioxide. You’re not going to have any photosynthesis without magnesium, which is part of the chlorophyll molecule. You’re not going to have a very efficient photosynthesis without iron and sulfur and all the other minerals, because your physiology is all tied together.

If you want to improve the efficiency of photosynthesis, the first place to look is mineral availability—having that system work. So, if you don’t have a backlog of sugar as fructose or glucose, you want that sugar to be stored as sucrose. That changes the osmotic relationship; it changes the overall physiology of the plant. You’re also not going to have any sucrose if you don’t have manganese, because manganese is responsible for your sucrose-phosphate synthase enzyme as a cofactor.

It’s a system that works together. If you don’t have sulfur, you won’t have enzymes, because most of your proteins are initiated with either cysteine or methionine—your sulfur amino acid. C4 plants have a more efficient photosynthetic pathway. They have PEP carboxylase, as well as rubisco enzymes—after the carbon dioxide from the air binds with the hydrogen that is split off of the water by manganese. So, you have C4 plants and C3 plants, and the physiology that’s involved—but all of them require the mineral nutrients. And any one of those deficiencies influences the overall efficiency of the whole process. 

My first book, Quality Agriculture is available now!

Great news! I am excited to announce the release of my first book. Quality Agriculture, conversations about regenerative agronomy with innovative scientists and growers is available on Amazon in time for Father’s Day.

Have you ever wished to download the knowledge and experience of the leaders in the regenerative agriculture space? This book will give you many insights you won’t hear about in other places.

My intention for the Regenerative Agriculture Podcast was to bring together the wisdom and knowledge of growers and scientists who had developed deep insights into how agriculture ecosystems function when at their optimum. The wisdom that emerged from these discussions is valuable, useful, and can be applied right away. Many times I wished to write down and remember all the great information my guests have shared. So we did exactly that, and this book came to be.

You may have already been reading bits and pieces of these interviews in some of the blog posts that I have been sharing. There is so much in these interviews, the brief excerpts can’t begin to do them justice. Imagine an entire book packed with this level of experience, knowledge and experience.

You can read all the details about the book, its table of contents, index, some of the memorable quotes, and the excerpts we have posted, as well as links where you can buy the book internationally.

Several friends have been kind enough to share their impressions of the book. Here is what they had to say:

No matter what form of production agriculture you are involved with, Quality Agriculture is a must read. John uses his expertise to delve deep into ago-ecology with many of the industry’s pioneers. — Gabe Brown

Agriculture is at a crossroads, and we are beginning to realize that the current system is not providing the stability in our production system needed to overcome the variations due to soil degradation and weather during the growing season. This book offers valuable insight into a path forward to enhance our soils for generations to come and to provide the quantity and quality of food we need for food security. This book will require you to think about changes needed in our agricultural systems. — Jerry Hatfield

The human mind is a world to itself. This book is a collage of splendid agriculture minds with a common theme: embrace and emulate the power of life. The collective wisdom of this book will help you glean the kernels of truth in a research world built on a wrong premiseasking the wrong questions. If you garden, farm, or just enjoy the ecological world, build the correct foundation in your mind by reading this book. — Ray Archuleta

John Kempf, who has one of the most fertile minds in agriculture today, has done us a huge favor with this book by multiplying his knowledge with like-minded experts he’s interviewed recently. Collectively, this disruptive innovation of how we grow food will be the foundation of how we farm in the future! — Steve Groff

Inspiring and insightful interviews with true leaders in regenerative agriculture — David R. Montgomery

John Kempf’s book on regenerative agriculture is a great collection of the wisdom and experience of twelve different agricultural pioneers from around the country. John directs the discussion, unlocking one door after another on fascinating insights each of these experts have discovered in their work. I have met several of the participants over the years but learned much more from these interviews than from my casual visiting with them and hearing them speak. In every case, what the reader finds is the destructive nature of modern, industrialized agriculture that is focused on artificial inputs and unsustainable outputs. Each interviewee directs our attention back to the complex interrelationships found in the soils, plants, and microbiology of nature. This is a must read for everyone who farms and everyone who eats. — Robert Quinn

If you’re like me, you like to connect with folks that make you think. This book does that. I’ve listened to most of the podcasts, and I enjoy John’s innate ability to connect folks from many different facets of research, bringing them to a combined platform. This book allows you to go deeper, with the resources and data in the background as supporting evidence. I’ve read it from start to finish, and I’m looking forward to future volumes to expand my personal knowledge base. — Loran Steinlage

Knowledge about regenerative farming systems comes in many forms from many farmers, researchers, ag educators, and consultants. The challenge is sorting through all the information, learning what is possible, and putting together a working system for the land that matters. These interviews certainly expand and clarify the knowledge base of professionals who have spent their careers studying regenerative agriculture. A great read―you won’t be disappointed — Gary F Zimmer

You can buy the book on Amazon.  Please leave a review, and share the book with others. 

Thank You! 

2020-06-16T18:16:50-05:00June 17th, 2020|Tags: |

Change ‘pathogens’ to ‘beneficials’ by changing the soil environment.

if the pathogens can’t bring about that compromising of the availability of manganese by converting it to an oxidized form, the fungus is essentially just a good saprophyte in the soil.

Don Huber describes for us once again that ‘disease’ organisms can only produce an infection in the correct environment. In a healthy environment, these same organisms develop symbiotic relationships with the plant. Our task as farm managers is to manage the environment properly, and crop ‘dis-ease’ vanishes.

You can listen to the entire episode here.

Don: A lot of your nutrient relationships—where you have microorganisms that are responsible for changing the valence states of various minerals so that they’re more available or less available. And you have those going on in both directions at the same time in some capacities. It’s an issue with manganese or iron or some of those things. Some of the secondary functions come into play so that all of that can take place and manifest in a very positive manner. Even though what you might be looking at—or the tests that you have—may not show the complete picture, you have to realize that it has to be going on, in order to complete the cycle.

And so, it’s a matter of either developing the techniques or understanding how all of those organisms interact—the ecological niches that make the system work. Everything isn’t just one big pool with somebody stirring the whole thing around. You really have a community of functions that are taking place at the same time, but you don’t have the same gas station at every corner or a grocery store at every corner. You have each one of those different functions taking place in its own little scheme of things. So the overall system is a very functional and very dynamic relationship relative to the plan. And it’s neat.

John: One of the pieces that you and I have discussed in the past is the challenge that we are seeing today with manganese availability. I would say that as much as 80 percent or more—perhaps even 90 percent or more of the crops that we work with today—come back showing inadequate levels of manganese. What are the major factors that contribute to that?

Don: Manganese has a very dynamic relationship with the soil, and also with many of the fungi. There are organisms—mycorrhizae—that increase the uptake of manganese, as well as zinc and phosphorus and some of the other nutrients. So, if they’re not functional, you miss that ability to absorb and to interact with a tremendous volume of the soil—where that mineral might be in short supply.

The other thing is that you have bacteria that are responsible for the valence state. You have the oxidizing groups. You have the reducing groups. The plant can utilize only the reduced form of manganese—the Mn2+ form. Mn4+ form is non-available, but we see it primarily in the soils that have high phosphate levels or high oxidative relationships—the manganese can be there and yet not be available for uptake. We see it with many of our pathogens, because the pathogens utilize manganese oxidation as a virulence factor.

We looked at several thousand isolates of Gaeumannomyces graminis, which causes take-all all over the world. We evaluated those and we found that there was one characteristic that was common in all virulent farms—manganese oxidation. If the wheat had oxidized manganese, it would never resist the disease. The same thing for rice blast. The same thing for isolates of Streptomyces scabies and a number of other pathogens. The ability to oxidize manganese to a non-available form—and to compromise the resistance of the plant to those pathogens—if the pathogens can’t bring about that compromising of the availability of manganese by converting it to an oxidized form, the fungus is essentially just a good saprophyte in the soil.

Same thing with many bacteria. So, we see these direct effects on mineral availability being involved not just in growth and quality and nutrient density, but also in susceptibility or resistance to disease. You have the virulence relationship of the pathogens with bacteria and fungi in the soil, and that’s related to those minerals that are necessary for the plant’s defenses. Those minerals are also directly related to the growth and resistance of the plants to those pathogens in their overall physiological function. It all fits together very nicely if the system is balanced—if it’s favorable.

And that’s one of the things that we can adapt to. When we’re farming, we’re really managing an ecology. It’s not a matter of a silver bullet for this problem or a stinger missile for another. It’s really a matter of having ecology work for us and support the plant. And if we don’t do that and we upset the system, then we compromise the overall quality and productivity potential we have in our soil.

John: You said that there are a number of pathogens that are dependent on manganese oxidation. And if they’re unable to oxidize manganese, they just become saprophytes in the soil profile. Are they dependent on that manganese oxidation directly—do they individually require it? Or are they just producing a manganese-deficient plant that is now susceptible to invasion?

Don: Both of those statements would be correct. They don’t necessarily need the oxidation. Some of them are also reducing organisms. In other words, if you change the environment—or if you change the association that they have with other organisms—then they may be strong reducing versus strong oxidizing organisms.

We see that especially with the Pseudomonads and a number of other organisms—you change the soil environment and they can benefit you, or they can be synergistic, or they can even be a direct pathogen, involved in compromising that resistance. The microorganisms use those minerals just like a plant does, or just like we do. Our metallo-nutrients, or strong transition elements, or electron transfer and physiological processes, are the cofactors for enzyme function. We don’t require very much of them, but if you don’t have that specific cofactor that’s involved for an enzyme, that enzyme isn’t going to do any work for you—it’s just another protein that’s sitting there. And about 80 percent of our proteins in plants are what we call metallo-proteins, where the metallo part is a cofactor. It’s a small part, but a very critical one, as far as function of that physiological pathway.

John: In essence, what you’re describing is that as long as plants have adequate availability of reduced manganese, they have resistance to all the diseases that you described.

Don: It would be very, very critical for that resistance—for the physiological functions in in the plant—without those minerals.

If you have read this far, you are welcome to join us for a webinar June 19th, at 11 AM EDT where we will discuss how to increase reduced manganese availability in soils.

2020-06-11T07:43:44-05:00June 12th, 2020|Tags: , , |

The problem, and large opportunity of manganese availability

Most agricultural soils today do not supply adequate levels of manganese to a crop. This is a foundational problem, because of the need for manganese in the water hydrolysis process at the beginning of photosynthesis.

When water is absorbed from the soil, and used for photosynthesis, the first step in the process is that the water molecule needs to split into H and OH, hydrogen and hydroxyl. This process is called water hydrolysis. Without this crucial first step, the photosynthesis process is blocked or greatly reduced. The water hydrolysis process is completely dependent on manganese to function. The macro ingredients needed for photosynthesis are chlorophyll, sunlight, water, carbon dioxide, and manganese. Even if we have generous levels of the first four, when manganese is low, it becomes the bottleneck that slows down the photosynthesis process.

We observe inadequate manganese levels in plants almost universally. You can observe it visually, quite easily in most plant species. The leaf vein should be at least as dark green as the area between the veins. When the veins are lighter in color than the area between the veins, this is an indicator of a low-level ‘hidden hunger’ manganese deficiency, and manganese being a limiting factor in the photosynthesis process. You can observe this easily on most plants, crops, cover crops, and so-called ‘weeds’.

I have learned from experienced agronomists that this systemic challenge with manganese has not been present historically. We now know that glyphosate, AMPA, some other pesticides, and oxidizing microbial communities all contribute to manganese being chelated and oxidized in the soil, and not available for plants to absorb. Many soil have generous levels of manganese in the profile, it only needs to be released. I will be hosting a webinar on Friday June 19th at 11 AM EDT describing the cultural management practices and tools that can be used to release the locked up manganese in the soil profile. You can sign up to attend here.

Robert Kremer discussed these interactions in our fascinating podcast interview:

John: In our experience working with many different farms, I would say, just off the top of my head, that greater than 90 percent of the farms we work with have experienced severe manganese deficiencies. I wonder about the long-term effects of this. When you have glyphosate accumulation, you have this shift in the fusarium population, and you have oxidizing organisms that are immobilizing manganese. What are the long-term implications of that manganese immobility in the soil profile? How long does it take before that manganese might be released and converted back into a form that the plants can actually utilize?

Robert: Yeah, that is a concern. I think there are several issues here. You have the effect of the shift in the balance of the microbial diversity. It’s shifted toward a lot of manganese oxidizers, causing manganese not to be available. I think that over time, if one were to alter the management to include, let’s say, cover crops—or at least different crops within the rotation—this could stimulate other types of microorganisms that will help free that manganese, or that will at least compete with those oxidizers to reduce their impact. So that would be one possibility. And how long that will take, it’s hard to say. It may take a couple of seasons, or maybe less. That’s something that really needs to be looked into. 

The other issue is something we mentioned previously: how much manganese can be immobilized or chelated by the residual glyphosate and the residual AMPA? That, I think, is a very serious issue—especially in soils where the texture is such, or the level of phosphorus is so low, that you don’t have any competition with the glyphosate or AMPA. They will obviously chelate or immobilize manganese as well. I don’t think we have any real good information on how long that can happen or what the extent of that situation is as far as tying up manganese over the long term. Taking all that together—the shift in the microbes, the residual glyphosate and AMPA, and the basically continuous corn-soybean rotation—if that continues, the manganese problem may persist.

John: When you speak of bringing crops into a rotation to help reduce some of that manganese and to increase its availability, what are some crops that are really effective at having a reducing effect and shifting the biology and the availability of manganese in the soil profile?

Robert: I don’t have any specific ones in mind, but certainly when you have a diversity of cover crops in a mix, there will be some that will support different microbial communities that are able to mobilize these micronutrients, and others that can actually mobilize the nutrients themselves. A common example is the use of buckwheat, or some of the brassica crops, which can mobilize phosphorus or neutralize nitrates. 

And then let’s say you add something like sorghum to the rotation—grain sorghum or sweet sorghum. From my experience, sorghum has a keen ability to host a lot of mycorrhizal fungi in its root system. And mycorrhizae are very adept at mobilizing many nutrients—not just phosphorus. If you could add a crop like that, or other crops that can host mycorrhizae, that would be a very good way to get around the manganese problem, to improve regrowth, and to improve the overall diversity of the microbial community.

Low level manganese deficiency in peaches:

2020-06-11T06:52:31-05:00June 11th, 2020|Tags: , , , |

Oats, a very effective disease suppressive cover crop

Many have observed the plant performance improvements of crops being grown after oats. It is fairly common to observe not only an increase in disease resistance, but also a yield increase because of the increased manganese availability, which increases a plants (and animals) reproductive performance.

But there is another very important point hidden in this dialogue. Before crown rust was a significant challenge, oats did not have a reducing/disease suppressive effect. The plant secondary metabolite profile of oats changed once they were bred to be resistant to crown rust. This change in the metabolite profile resulted in a changed profile of root exudates, which converted a plant with a former oxidizing effect on the soil redox environment – a disease enhancer, to a reducing effect, or disease suppressive.

This means we need to consider the possibility that some plants which currently have an oxidizing effect, such as modern wheat, can be shifted to having a reducing/disease suppressive effect when we change the plant metabolite profile. We know we can change the plant metabolite profile significanly based on how we manage plant nutrition. Breeding is not the only pathway, and certainly a slower pathway, to developing crops which produce a disease suppressive microbiome.

From our interview:

John: You spoke briefly about the use of crop rotations and that 85 percent of the effect, in terms of disease suppression, happens from the prior crop or the prior cover crop. What are some particularly useful crops or cover crops that have a very strong disease-suppressive effect?

Don: Again, that’s going to depend on your disease and your overall soil biology. For instance, if you’re dealing with take-all, Gaeumannomyces graminis—the root and crown rot of cereal crops—you’ll find that brassica species have a suppressive effect. Perhaps the best cover crop overall is oats—another cereal crop. When we bred crown-rust resistance into oats, this also gave us an oat crop that provided disease control—take-all control—for our wheat and barley.

The reason is that crown-rust-resistant oats also produce a glycolcyanide root exudate that suppresses the manganese-oxidizing organisms. If you suppress the manganese-oxidizing organisms, you also suppress the manganese oxidation by the pathogen that is required for virulence. So you’ve increased the manganese availability for the plant—for its own resistance.

The shikimate pathway is a pathway that gives tolerance or resistance to take-all, because that’s where the lignotubers are formed. Lignification and callousing—all of those materials are produced through the shikimate pathway. And manganese is a very critical component in that pathway—at six or seven different steps in the pathway. If you inhibit the availability of manganese—if you have a good, strong mineral chelator that ties up manganese—you’re going to increase take-all, because you reduce the functional availability of manganese for the plant in its own defenses.

A plant like rye is very efficient in the uptake of manganese and other micronutrients. Rye takes care of itself with its resistance to take-all pathogen, but it doesn’t do anything for a subsequent crop. It does very well, with very little disease pressure, because it’s very efficient in taking up manganese and other micronutrients. If you have triticale, which is wheat-rye cross, if it doesn’t contain that section of the rye chromosome that is responsible for micronutrient uptake, then the triticale will be as susceptible to take-all as a wheat crop.

You don’t get a crop-rotation benefit out of rye like you do from oats. The root exudate of oats has a very strong antimicrobial compound against the manganese-oxidizing organisms that make manganese less available. You’ll see that effect—that change in the soil biology—carry on for two or three wheat crops after an oat crop. Subsequent crops will have very little take-all. Oats probably has the most dynamic effect in this regard.

Brassica species—canola or mustard—also produce quinolones and some other materials that have a similar ability to reduce take-all as the glycoprotein in oats. Following canola, you’ll see an increase in some of the other diseases. It’s not just influencing one particular disease. If you’re using Roundup-ready canola, genetically engineered canola—where you’re adding a very strong mineral chelator, because that’s how glyphosate works, by tying up those minerals in the physiology of the plant—if you’re growing Roundup-ready canola and applying glyphosate, it’s going to move out of the root exudates and change that soil biology. Then you may see a reduction in take-all, but you see a very dramatic increase in Fusarium root rot, as well as Fusarium head scab and the toxins of that particular plant pathogen. So, you’re changing the dynamics of the system with the particular management tools that you use. 

Discontinuing all pesticide applications at once

The most intriguing element of the interview with Michael McNeill was the suggestion that you should stop all pesticide applications all at one shot. I know it can be done because this was the approach we took on our farm years ago, but I have been hesitant to recommend that leap to others.

Our approach in our consulting work has been that we have to earn the right to discontinue pesticide applications by producing such a healthy crop, it becomes resistant to possible pests, and you no longer need the pesticides. Of course, achieving that outcome is made much more difficult from the continued pesticide applications.

We also have slightly different contexts. We are working with many high-value crops, with more intense pesticide applications, where we don’t have the luxury of making any mistakes. Of course, broadacre producers would say they don’t have the luxury of making any mistakes either.

In practical application in the field, I am comfortable making recommendations to discontinue the use of fungicides and insecticides when we have sap analysis reports, and we can observe the nutritional profile of the crop is not conducive to infection.

In any case, who can argue with success?

From the Regenerative Agriculture Podcast with Michael McNeill:

John: Michael, what is the one action that you would advise all growers to take right now that could make the biggest difference in their operations?

Michael: Stop poisoning the soil.

John: I guess that’s easy!

Michael: It’s real simple—just stop.

John: That sounds simple. It sounds easy to do—but how? How do you manage that?

Michael: It is a challenge, if you’ve spent most of your life doing things one way. Stopping doing something is not necessarily easy. But that’s the one action growers need to take to be successful.

John: Are there transition steps that can be taken to move away from that? What are what are some of your growers who have moved away from using herbicides doing?

Michael: I have seen a full array of actions—from taking baby steps to jumping off the cliff—100 percent stop. And I have seen growers—from the smaller, 300- to 400-acre growers to the 10,000- to 15,000-acre growers—step off the cliff. And it’s worked really well for them. I was really concerned about some of the larger growers, but I found that they had the management ability and the resources to make it happen. And once they understood what they were doing and why they were doing it, they were very successful.

And I think that’s something that most people don’t believe. I get that thrown in my face almost every day. “I can’t do that—I have too big an operation.” And I really enjoy throwing it back—”Well I know somebody who has.” Those successful large growers have not necessarily added more hired men or anything. The one thing that they have added—if they’ve made a mistake or a failure—they’ve had to employ a large number of people for a short period of time to hand-weed a field. If they made a mistake, that’s the only fix there is.

John: I’m struggling with this a little bit myself as well. So, when you use the words “stepping off a cliff,” are you talking about eliminating 100 percent of all herbicide applications right out of the gate? What does that mean, exactly?

Michael: All pesticide applications.

John: Aren’t you going to lose your crop to potential disease and insect pests when you do that?

Michael: When you do that, you’d better have read that book that I just suggested (Mineral Nutrition and Plant Disease – Datnoff, Elmer, Huber )—so that you understand that you need to have the right micronutrient balance to keep that plant healthy enough to protect itself. And you can do that through starter fertilizers, foliar feedings—multiple foliar feedings—you can pull it off.

John: What are some of the failures of growers who have tried to do this, and what has been their degree of success?

Michael: By and large, I have had all successes. I’m trying to think of a failure, but I really can’t think of any. I make sure they really understand and know what they’re doing when they do it. I’ve had a few where they missed a field or two, timing-wise—a rain caught them and they didn’t get the weeds taken care of when they should have. But they were able to get it cleaned up—to the point where it did not suppress yield.

John: Wow. How do their yields compare?

Michael: I think that their yields have been going up. That’s what’s been somewhat shocking. I want to be sure it’s attributed to that—not just necessarily a good growing season. Because we’ve had some good growing seasons recently. But their yields have continued to climb quite rapidly. They’ve moved to a different yield plateau.

John: So you’re saying that their yields are actually higher now than they were when they were using herbicides and pesticides regularly?

Michael: Yes.

John: Well, that’s exciting, because those are the same types of things that we’ve observed in the fruit- and vegetable-production world. And those are really the types of regenerative systems that we seek to create and to establish, and I absolutely agree with you that those are possible.

From a management perspective, the one piece we often do a bit differently on fruit and vegetable crops we work on is that we don’t usually advise people to “step off the cliff,” to borrow your terminology. Rather, we advise growers to manage nutrition and to regenerate soil health to a higher plateau of performance—to the point where growers earn the right to eliminate pesticides. Then, all of a sudden, we don’t have problems with powdery mildew anymore. We don’t have problems with spider mites anymore. We don’t have problems with leafhoppers anymore. When we get to that much higher plateau, and we no longer have the problems, then we start cutting and eliminating pesticide applications.

It seems a bit scary to me—when you’re managing a crop that is really valuable—to suggest eliminating all pesticide applications immediately. But obviously, you’ve been successful in doing so.

Michael: Yes, it’s worked. And it was really scary when I first started doing that. But I’ve learned the few things that you have to be sure to accomplish: getting the soil as healthy as you can, and helping the plants be as healthy as you can. And that’s pretty hard to do when stepping off the cliff. But it can be done.

2020-06-08T11:49:26-05:00May 29th, 2020|Tags: , , , |
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