welcome to the science for the public lecture series science for the public is an organization committed to bringing the science information issues to the general public this is our website for our program good evening i mean van step for science for the public and i welcome you to contemporary science issues and innovations tonight we're honored to talk with david montgomery and declare the authors of an important new book the hidden half of nature the microbial roots of life and health david armand gummer a is a professor of geo morphology at the university of washington and a macarthur fellow he's an internationally recognized geologist studies landscape evolution and the effects of geological processes on ecological systems and human societies dr montgomery is the author of three award winning popular science books and he's been featured in documentary films t v and radio programs including nova and all things considered for more about his important work please check his website and it's on our event page as calais is a biologist who works on watershed restoration environmental planning and public health she works extensively with community and nonprofit organizations on environmental stewardship these husband and wife authors of the hidden half of nature have made an important contribution in the book that's our main topic tonight they have emphasized the connection between microbial life in healthy soil and vitality of ecosystems and the relationship between healthy microbial communities in the human gut and general health including the immune system microbes matter it's a great pleasure to lynn comrie and declared welcome folks thank you so much for making time for us in this hectic schedule while you're on the coast here yeah i saw our pleasure really great was ok and could you please start us out with just what's soil because we're always thinking we should wipe it off of our shoes but it is kind of vital could you give us a little background sure if you really want to get in trouble with a soil scientist you call soil dirt right so that's exactly what i called my book about well yes i think it's getting in trouble is not always a bad thing when you're raising awareness of something like soil which is probably our most valuable but least valued resource if you think of what separates earth from mars as sort of a habitable environment you this obviously the atmosphere and water those are the first things that come to mind that the thing that people don't tend to think about is soil healthy fertile soil is really the catalyst that helps drive elements from the dead rocky crust of the earth and into the biological world it's that that frontier we like to think of it as the marriage of geology and biology of course and geologists in a biologist might think that way yeah but that's really sort of the essence of soil is it's that transition between those worlds it's a dynamic catalyst that keeps the wheel of life turning in a very  in terms of what it's composed of in the book dirt and i believe in here you mention and i think most of us are not aware of it rocks that are also right to it so that marriage between rocks and microbes is fairly critical and could you just give us a little understanding of how that becomes dirt yeah i mean microbes are one of the key factors in breaking down rocks the more we've learned about that over the last few decades more we've realized how certain microbes can actually go out like little miners and prospect for certain elements that are locked up in rocks get them out and get them into biological circulation integrate them into their bodies and then they can either trade them to plants or when they in turn die it's actually in biological circulation and if you look at the all the things that make up living matter the plants and animals that we know of as nature  a lot of it's obviously carbon there's nitrogen oxygen the things that that plants can can get fairly readily but there's all kinds of other elements that are really critical to building the bodies of life that ultimately came out of rocks and rocks don't break down very fast i mean take a rock put it out on the sidewalk somewhere you can keep coming back and find it in much the same shape for a long time microbes are one of the key elements that get those elements out of the world of geology and into the microbes and the rocks work together to help provide the basis for the yeah ok and both those elements that you mentioned ultimately came out of rocks ok once they get into the biological world they can circulate through living matter to then dead things or danica matter that once it gets back into the soil if it breaks down can get reconverted intelligence in a form the plants can take back up and that's where the whole idea of a wheel of life concept comes in because microbes you might think of as certain nature's recyclers agers little miners and recyclers and we depend on them for the ultimate source of much of our nutrition but it's kind of a few steps back down the road before it gets to us so we don't have time to make those connections right so that's really very interesting i'd like to recommend to viewers that that there are parts of this in the bible both in this book the new book the hidden and hidden half of nature and also in the clock dirt which is just a gold mine of information and speaking of that we have destroyed soil a great deal we're kind of aware of that now but in the book th earlier book der made mention of that could you tell us a little bit about that before we get to your garden yeah i mean the working on that book was what really sort of got it and i both into looking into the world of soil and i'm a geologist i travel trying to look backwards in time to look at the history of life and if you do if you take the same kind of view to the history of civilizations one of the things that you recognize is the profound importance of soil and soil fertility sort of healthy fertile soil as the foundation for a thriving prosperous civilization and it turns out that after we sort of entered the agricultural world in the sort of the post glacial era of a more of a nicer climate and we started growing a lot of our through food with agriculture there was a downside to it on the upside we sort of were able to expand our numbers more people on the downside is that many of our agricultural practices degraded the soil at a slow pace but nonetheless at a rate that added up over the centuries and if you look at a recipe for undermining a civilization growing your population while degrading your ability to feed future generations is not a good  civilization so in the dirt book i look back at the history of societies how they treated their land and came to the conclusion that the way people treat their land over time will look determine the ability the land to sustain those very people and it's  you know in that there's a relationship between societies and the soil that influence each other and that that was a bit of a revelation to me into looking through the history of humanity you can think of the state of the soil as i would think is the long wavelength periodicity of the rise and fall of civilization influenced by the health and state of their soil if you have a lot of soil in a small population a lot of fertile soil it's a recipe for growing a population and once you get to the point where you've degraded much of your soil it is a it sets up a recipe for instability it makes societies vulnerable to climate shifts droughts for example or in climate shifts like we're undergoing today or hostility with one neighbors those kinds of the facts which are the things that we see in history books when we actually look at it but playing out underneath there is really essentially our relationship to the land and its ability to support us yeah and that i really fasting because we don't usually think of that we don't make that connection with the ends of the civilizations so that is really great information by itself our forefathers did this on a pretty regular basis long before industrial agriculture because they didn't know but now we're learning quite a bit and then has developed considerable expertise about restoring soil and in this book you have this wonderful narrative of constructing soil in your backyard could you tell us how you did that sure well i had very much wanted a garden shortly after we bought a house in seattle and it took us a few years to get going on things and it was sort of a little bit of a debacle as we are going on our garden project because there we are nearer the middle to end of august and that's where we landed on getting hundreds of plants into the ground as we're digging we're encountering two problems by this time in seattle even though it rains a lot by the time august rolls around the soil is really pretty dry and we also encountered glacial till which is a concrete like layer in the soil in our lot it's anywhere you hit that about anywhere from eight to twelve inches so we're getting these plants into the ground and it is turning into a watering nightmare and i thought we need i need because i'm i'm i'm really more the gardener something but i thought mulch i need mulch and a lot of it and right away and we had sort of blown our budget on the plants themselves and so i thought what is close by cheap or free and that i can haul home and so changing i began to think ok let's see i am hearing arborists in the neighborhood and so they fill up their truck with wood chips and they otherwise have to pay to dispose of that i would call them and say no how about you come and dump your wood chips in our driveway so that was one source home it was something like you know starbucks will package up their spent grounds in a bag about why this size and i think i estimated somewhere around i don't know three or four hundred of those bags this over the court the course of maybe eighteen months or so that was mix that with wood chips and then asphalt came around leaves are falling yeah that is some of the best mulch material in the whole world and i it just breaks my heart every time i see people binning up their leases setting them on the curb to be in the way make any sense right and they understand you have space problems for storing their leaves but if you just let them sit for a couple of months they quickly sort of you know you're a depressant volume and so i would mix various things together along those lines wood chips coffee grounds and other things and then layer that mulch on the new garden beds from anywhere you know from say this depth to maybe upwards of this and that was doing a couple things that really cut down on the amount of watering we were doing so that was the key thing and also i hear a lot of gardeners you say well i have trouble one of the best things that this was all new to me was the organic soup yes so so here you get you're getting a recipe for how to do this and then on top of this you had so oil soup that you might consider it a little bit like a probiotic mix for your garden and in this case i had castings from the worm bin and you put that in a container and five gallon container you carry that water and you had a nutrient mix and all of the microbes bacteria fungi all of the things that are in that compost then begin to multiply their populations begin to grow because they have a food source and i let that brew for anywhere from twelve to forty eight hours and then i have a special sprayer and i'll put my  i'll put my soil soup in a watering can or a bucket of some sort put the sprayer and into that bucket and then i can go around the garden and spray my soil soup a licks or and i have to say  roses i really notice it with roses which in the northwest are prone to funny little blights and molds and things that get on their leaves and every time i fall down on soil souping the roses these things creep back up on the leaves in the petals but when i do spray it with soil sue they don't come back and there's a there's a bit of debate amongst researchers and scientists are really looking at soil suit because all of these brews are different you know or my microbial populations are different than the neighbors microbial populations in terms of say the worm compost that we're using so it's not entirely replicate all i can tell you from anecdotal evidence in our garden and my own observations is that it really does seem to work for certain problems and i don't think it has done any harm right that brings me to the subject of the microbes themselves and you are and the worms that as a great contribution you mentioned first of all i should ask how long did it take you to get that soil built yeah go ahead well we first started seeing changes within a few cater after was about five or six years when we eventually dug a hole and found there's almost two inches of relatively really pretty good new soil on top of that glacial till that and mentioned earlier turning that back into the raw material that was fueling an explosion of life above ground and also other organisms that was starting to come back and build on that microbial foundation right could we talk about that going to draw that out just a little famous associated with this who took a lot of heat for a long while but it's widely recognized now but this is a running theme in your book even when we get to the health aspect but so you've got microbes but it's not just microbe a and micro be right could you give us an idea of those communities the symbiosis tractor in there and then how that developed the the how the earthworms came back and how everything else came back sure how about i'll start off and then dave has a great analogy that he uses for for all of this so symbiotic relationship are merely ecological relationships where two organisms or two communities composed of different organisms actually each are interacting with one another typically in ways that benefit each one so that you know community or microbe a community or micro be when they come together and interact they're accomplishing things that neither one could do by  themselves so it's a it's a partnership really is what it is and this is a very different way to look at evolution because for such a long time it's been in grain i think in a lot of us that evolution is a process of competition and budding hessen it's this organism or species overtaking this one and it evolution is really a process that happens along a continuum depending on you know the size of an organism say a big elephant or something like that versus a little tiny microbe these kinds of life forms are doing all kinds of different things in the process of surviving and reproducing and so with microbes which are these invisible single celled organisms they don't have you know teeth and claws and they're not conquering and killing things the way we think of  nfortunately now deceased lynn margulis who came up with a theory called symbiote genesis and that was she laid out a way in which long long ago billions of years ago two microbes came together and did the unthinkable one ingested the other but both survived and if you you viewers want to look into her work and there's a whole line up there's a whole story there that is absolutely fascinating and so margolis followed this thread and she came to see that indeed symbiosis that had begun in the microbial world led to the so called higher forms of life the multicellular organisms the likes of of all of us here our cats our dogs our our pet goldfish and so on and dave has a interesting thing that that he observed sort of about symbiosis in the order in which life return to our yard after you know shortly after we had really got going on the garden you know as as the garden developed and the soil was changing and the plants were changing we noticed different animals coming back in the yard and there was a sequence to it you know the microbes obviously we didn't see but we're but and it's adding them and it and feeding them with the organic matter and then worms started to come back and then arachnids came back the spiders came back and then the birds that ate the spiders  and ultimately all the way up to an eagle that came to eat the baby crow from the crow family that was eating the worms that came back to the lawn so we got back to our apex predator and yeah it'll and the order in which those things organisms and the pearl is actually quite striking the timescale of course is completely different you know ten years in our yard and we're time on hundreds of millions of years on the on the continents but what it really emphasize to us is the levels of diversity and interactions and the parts that we just sort of learned as we looked into other people's work and in writing this book was was the real importance of partnerships between microbial life and some of those higher order for it turns out that when you look into those relationships a in the root zone of a plant there's a particular microbial communities around the roots of particular plants that are very different and it's kind of  what are they doing there and it's incredibly rich zone of life that zone called the rise a sphere the zone around the rooms on the most of the life dense part of one of the most life dense areas on the planet or right around plant roots and it turns out that plants actually push out through their roots sugars and proteins out into the soil that feed those microbial communities growing in their root systems and you'd wonder why would plants do this is not a terribly good strategy to capture solar energy and then just go give it away unless of course the plants are getting something back from those microbes and it turns out that one of the things we learned in researching the book was not only that plants will put thirty to forty percent of what they capture to devote a synthesis out into the soil to feed those microbes but those microbes consume it turn it into metabolites that turn out to be things that are very beneficial to the plants things like plant growth promoting hormones some of the some of those microbes will help soluble eyes phosphorus that's in the soil or they'll they'll grab nitrogen this out of out of that's locked up in the soil or will help help degrade organic matter and return those nutrients back into plant available forms so by feeding the microbial life those plants are essentially outsourcing chemical factories if you will in the so outsourcing contracts to chemical factories that in return and supply them with things that promote the growth of the plant and you have there are a virtuous circle the plants are providing the microbes the microbes are promoting the health of the plants and that's an example the kind of symbiosis that enters mentioning that clay and why your garden was so incredibly healthy without the need of any biotics for and they think right right which takes me to this other question it implies that modern agricultural methods are radically different from this and do you see that in the root systems of plants crops from that are grown in the modern agriculture these are huge job mondo crops and things that are not organic you know one of the things that one sees in terms of plants that you apply a lot of fertilizers to is the n s a then they kind of have it easy they don't have to work so hard to get the big nutrients the nitrogen potassium that we're feeding them in those fertilizers and so they'll cut back on the exit dates they produce they're not trying to recruit as many microbial partners now the problem with that is not that you can't grow plants because you know them fertilizers can grow bigger plants but what about all those micronutrients the other elements that the microbes are helping to get from the soil and into the plants the copper the coal ball all the sort of the what we call the micronutrients those other elements other ultimately coming out of the rocks or out of recycling organic matter so when the plants crops close down their exit date faucet they sort of turn that down in the soil the microbes that were specialized in eating those exits and producing things that benefit the growth and health of the plant they don't thrive you'll get other microbes will be will be will be more prevalent and so that changes essentially the  nutrient acquisition army that the crops would would have had and so you do see differences in terms of what the micronutrients cycling in the soil there's been major decreases in micro new content of crops in the last century but of course that's complicated by new crop varieties that are bred for high yields rather than reading the traditional quality and there's also the question of you know if you continuously go for higher yields are you depleting the reservoir of nutrients in the soil so there's lots of things other than this microbial connection but the science dots in terms of all the mechanisms through which this can work are pretty well connected in looking at the way that if you've i just want to put a point on something and that is the other thing that happens when plants get fed fertilizers and they they start producing these exit wounds which cuts down on the food supply for all of these microbes that are congregating around the roots is that those microbial populations begin to die off and with that is all of these metabolites these microbial metabolites that are functioning to the plant as signals about a number of things nutrient concentrations in the soil the presence or approach of pathogens and so what that means is we're sort of taking away a plant defensive system ok and this is this is the big problem because here you have this gorgeous luscious plant stuffed on fertilizers and we've all seen gardeners and farmers have seen what fertilizers do to plants i defenseless plant and then that puts us in another bind which is we're very concerned about our gorgeous luscious plants and so then the poisons come out to kill the past and pathogens that have come running to the plant and with the microbial populations that formerly were present it's like the gates are wide open in income the marauders and down comes the plant in less the poisons come in and as dave mentioned a sort of a virtuous cycle there's also all of these negative feedbacks once we begin starving the soil of organic matter which then causes these microbial communities to plummy thanks for emphasizing that because we  a lot of propaganda about how it is absolutely is two things that are essential you have to have these enormous mano crops you have to do it this way we'll get a new genetic variation to solve the plant problem whatever it's weakness and the othe r is you've got to spray it all to death you know that to get rid of the things and what you did was restore the system in the first place which eliminates the need for fertilizers and everything else just everything goes back to the soil and get if you have a healthy soil you have in abundance of microbial life as well as you know larger forms of soil life you know earthworms in those hold i right you know we call them the chewers and choppers so when soil is healthy plants are healthy again you cannot have a healthy plant without healthy soil yes and that then that health transfers to us and i would just like to  the roots are attenuated and then you point out the entire biological community is somewhat devastated down below there that it really adds to the nutritional value right plan microbes it's the fuel source and so one of the one of the other unintended consequences of fertilizer intensive industrial agriculture has been that the organic matter content averse oils that  the batteries for for soil life have been depleted by a factor of about fifty percent in the us that's probably a reasonable number globally as well yes that's going to super agriculture and what that means is that if you at the organic matter as essentially the fuel for the microbes that are helping facilitate the processes that build soil fertility then the more fertiliser we over apply the more we need to apply because we're degrading the natural reservoir of fertility now and if there was an infinite source of energy available at no environmental cost and infinite supplies of micronutrients that wouldn't be a problem but none of those if  want to ask you a time about now the relationship between our health and this and here you've made this connection and to my knowledge it's the first time it's all been put together all the dots  been connected so we start with you build a healthy soil that creates very healthy nutritional produce from that correct and then we eat that stuff and we've only recently come to understand that we have a micro biome in us and right we really depend on it and we've discovered this at a time when we have as you pointed out a lot of chronic diseases replace seem in a sense diseases that used to be you know from particular germs services or whatever and we've solved that problem in a way but now we have diabetes we have all sorts of things and you're suggesting better check that micro biome right you have two very interesting stories your own health things if you tell us about that and the relationship to this micro biome i don't think that we have a lot of knowledge in the pub about our gut how important that is so tell us the health part in the middle of writing this book i learned that i had cancer that it was malignant and that it was caused by a virus and this was huge pause for thought especially that it was caused by a virus because we had just been through this experience with our garden and soil where microbes were absolutely essential to good health not the bad health of the soil and all of these plants as it turned out i'm thankfully now fully recovered and healed from that but i learned a lot about my own body through that experience and one thing in particular was the immune system my immune system and what a properly functioning immune system is like and what is it that it ought to be doing mine should have caught those cancer cells but it didn't and i began seeing different health professionals and one of them a cross all of these conversations it was immune system immunity immunity and i thought well i want to do something what can i do to support and strengthen my immune system so whether it's cancer or a cold i want that kind of a health challenge i want my body to work against that and so interestingly the conversation turned to diet and we dove deep into the human micro biome at this point and it turns out that the root of a plant in the human gut share an awful lot of commonalities and it has to do with organic matter microbes what these microbes produce with what they're eating and what the effects of their metabolites are both for a plant and in the human body and so here's here's how it works we've talked a good deal about the roots of plants and this special zone called the rise spear and it is chock full of microbial life and there's constant signaling and communication going back and forth between you know that plant above ground and its root system and deep down in the lower most part of our gut in our colon also known as a large intestine that is very much like than they think the root of a plant in that the highest diversity and numbers of the micro biota that compose our micro b and so we saw everything that was going on in the soil and we came to see a version a different version of of soil if you will down in our colon and so what's happening is our diet feeds all of those and what they thrive on most is complex carbohydrates your doctor calls this fiber a nutritionist calls this fiber and what was so interesting to us is that the fibrous parts of our food and so this is mostly our plant foods it's not so much fats and proteins but it's the fibers part of plant foods that pretty much escape our digestive enzymes we don't actually make the proper enzymes to fully digest all of the whole plant foods in our diet but sitting down there in our colon the tranquil pastures of our colon where you've got all of these micro or organisms and more importantly their genes their genome which codes for a beta makes somewhere around two hundred sixty different enzymes that break down all of this plant material and really what this is is this is organic matter that's coming into our bodies much like all of that organic matter that i was spreading on top of our guard is that interest right and so in the soil we have microbes breaking down all of that mulch the wood chips the leaves the coffee grounds all of that stuff and likewise deep down in our gut we've got the same process going on the breakdown of organic matter by organisms that have the enzymes to do this and the metabolites that are produced in our gut many of them have medicinal effects in our body and one of these compounds is called butyrate and what butyrate is very interesting because it's it's being produced in our colon and right on the outside of our colon wall is where most of our immune system is located in our media system is in part composed of a variety of very different cell types with really specific jobs and there's one kind of  that's a part of our immune system and it's very cool so what i'd like to point out here is just orient viewers here to are the slide this area called the lumen this is the central cavity in the colon so you picture your colon is a big circle like this in that interior area is called the lumen this slide is a cross section so we've taken a cross section through there and you have a thick layer of mucus and you've got members of the micro biome that live both in the lumen and in the mucus this here these are cells as it's described here that line the colon this is the outside area of the colon this is outside the colon wall in your abdominal cavity you can basically picture it and this is  dendritic cell which is this fabulous cell that sits there perched right on the outside of our colon wall and it's sort of an intrepid traveler if you will and the way it travels is it takes an arm and it slides it up in between these colon cells and it collects a sample molecular sample of the microbes and it comes back down out of the colon and it takes that molecular sample and it activates it's pal's called t cells and that's what what's happening here that molecular samples called antigen and particular kinds of antigen activate  particular kinds of t cells and in the world of microbiome research there's two kinds of t cells in particular that have drawn a lot of attention and have been a lot the subject of much research consider that like maybe a fire extinguisher in a fire ok there's another kind of cell that's a pro inflammatory cell it it begets starts and formation and that's called th seventeen kind of  and you'll see what's happening here is that the dendritic cell again this is sort of octopus looking cell grabs a sample from up in the colon it brings that down and it activates a to regulatory cell dend cells also can collect other kinds of molecular samples from our micro biome and those activate a th seventeen cell and day day to normally most of us are not walking around with cancer influenza or something like that you want inflammation to even keel in our bodies because when it's operating inflammations like it's sort of like an all in one wrecking crew is how we describe it it comes in and it can take you want that wrecking crew go in take care of the problem and get out as quickly as possible and so the th seventeen kind of a process fires up inflammation and gets it going but then when that's taken care of you want you t regulatory cells to fire up come in and smooth everything back down and get inflammation back back down to this balanced state and what's very different about  this whole new view of our bodies in the immune system is that it's really the presence of certain microbe not so much the absence all the time of certain microbes that is absolutely foundational for health because if you think of it what if we've got that dendritic cell you know on the outside of our colon wall it slips through it's grabbing a molecular sample it's coming back down and it's showing that to cease to t what if the kind of microbe that we need to activate it to rig cell is missing yeah or what if the microbial communities that sort of chaperone and and usher in this whole process what if they're scrambled you can see pretty clearly right away that there's going to be some miscommunication between these dendritic cells and the other cells in our immune system and so you have in this case it appears that auto immune conditions you know from asthma to diabetes which we have in abundance right we have a lot of those kinds of conditions and diseases so it looks like that's the direction in which things are headed and it will take more work to work out all of these connections but just going back to diet and this is why it matters so much about what we  because that feeds our micro biome and you want a micro biome that is you know is fully functioning as possible as we can have it here in our modern world that is so that we have the proper chemical signaling to activate you know our immune system as it should be activated when when we we need it to be and this is very interesting that you pointed out the things that are just at  huge levels now the american diet travels to other countries and the next thing you know we have record obesity in countries we've never had obesity in diabetes to all sorts of problems that have been linked as you say still corella to some cases but that look as though the diet our diet is really a major factor which is interesting because in the medical community there is a great emphasis these days on genes so if you have a broken fingernail there's a gene for that if you are obese there's a gene for that cancers a gene for that for everything cholesterol as a going to ask you about here it's all genetic but what you're suggesting is if you get this thing straight your immune system gets back to work that's very live in different environment so it's really a constellation of factors our environment our microbiome and our genes and it's the inner relationships between those three things that that sort of really influence our susceptibility but diet is such a big factor in all of this because it affects our micro biome who probably affects our gene expression and we know certainly the way that we grow food in the type and amount of chemicals that we use that interacts with our genes so it's really this big you know mill you if you will of everything that affects our health and the micro biome is just sort of the latest thing but it's very very informed it really is  before we leave that because we're going to run out of time and i need to ask you about the what what can be done in the future but dave you mentioned in the book that you had some various medical problems she's imposed a diet going  to here and tell us about that if you would please and then will yeah you know and i had a great influence on changing up our diet as a result of learning many of these things and i mean my doctor been telling me for years to eat more fiber but i'm not very good just following orders but once you understand the mechanisms the connection sort of why that is and once i understood that oh i would be eating fiber to feed the micro biome in my gut which would then be doing things to quell information that would benefit me as a oh that makes sense so over the course of about a year and a half after we started changing our diet i noticed some very significant health improvements of my own i had been on cholesterol medication like a lot of people a lot of people my blood pressure was too high a lot of people i had for a while i took little purple pills to try and address acid reflux like a lot of people and once we shifted our diet to him a more plant rich diet which is that we didn't give up anything and no meat we carry the full spectrum but we shifted the balance of what we know that it once you think about you know the first thing to do is feed your micro biota that makes sure that they are healthy so you can be healthy that gives you a different way to think about what you ordered a restaurant and what you make it home and i've lost a lot of weight i'm not in any prescription medications anymore my cholesterol came down my blood pressure came down sense those connections once you view it through restoring you've got microbiota it actually makes a lot of sense because for them to for that biota to be healthy they need to be fed like what all the ecosystem chronic disorders like high cholesterol blood pressure these kinds of things that just about everybody has any more you can attribute to diet down the line where as we've  been encouraged to think that we have to go get medication right and you're going to be on a long term medication which just complicates the thing more and more so there is a solution out there possibly and there's a difference sometimes between treatment and prevention yes  a change in diet won't be a treatment for everybody and right but it is the one thing that we all have readily at our disposal that does matter that we can't exactly influenced exactly choices will this brings me then because we're to run out of time unfortunately it too the issue of most of our food is coming from big ag right and that has a very different treatment of the soil that may have an effect on the actual  nutritional the net nutritional value of what comes out of the ground and animals and everything else in terms if you could restore the soil is that possible you know on a large scale are people trying to do it because we're told no you can't do that not only is it possible i just wrote a book about it it comes out in may it's called growing a revolution bringing our soil back to life and what it what it did is you know watching these revelations from an transforming our yard and looking at the history of ancient civilizations made me ask exactly the same that question could we restore soil at a large scale i described a large enough to actually influence the food system globally  and what i did is i went around and visit farmers around the world who have been adopting practices that are regenerative that rebuild soil fertility even as they intensively grow food and i was really impressed because some of these people have restored their soil remarkably fast you know in a couple decades gone from a half a percent so organic matter back to the native organic matter content whether it's you know four to six percent in african for you know eight to ten percent in some of the prairie states in north america and there's different methods that people have used to do this but what i try to look at are what are the common elements what are the commonalities between farmers and ranchers in different environments that really worked to restore their soil and restore fertility to their farm as it turns out restore profitability of our homes and look at one of the things that has happened in modern sort of industrialized agriculture is that farmers got really good at growing a lot of a very few crops yes and if you look at sort of classical economics what does that do to it'll depress the price you can get from that you over produce you produce a lot of something and the price will go down but the price of inputs that they've relied on increasingly for the last fifty sixty years the fertilizers to pesticides have gone up fairly dramatically as a limited number of seats and that's not even mentioning what they mean is paying for proprietary seeds which they use i don't pay anything right and who's who's basically squeezed in the middle it's the farmer because that what they can get for their harvest is gone down what they have to pay to grow it has gone up so many of the people i visited were people who were sort of caught in that squeeze and were a personal economic crisis to think differently about how they were approaching agriculture and so they were trying to innovate in ways that would allow them to use fewer inputs and the combination of practices that really seems to work to build saw fertility is to cut down on soil erosion by going to know till practices have stopped plowing and it's we talked a bit earlier about you know the undermining of civilisations over time and the plough was actually a big piece of that because if you plough the soil it leaves it bare before the next crop and erosion can happen faster than nature rebuilds the soil and if you lose something faster than your place that you actually can run out of it takes a long time to do that for the soil but it can happen  so going to no tillage and then many people will think that that actually requires intensive ag chemical use the use of herbicides many of the farmers have as it are not doing that and then using other methods they're using cover crops to  three practices no till cover crops that include legumes things that bring one hundred back into the soil and then also a diverse rotations are not growing the same thing that setting the banquet table every year at the same time for the same organisms it's what we now call conventional agriculture because these people are reducing their their chemical inputs by fifty percent to ninety percent and saving money doing it so it was more profitable for them so they were like why would i  exactly and their neighbors eventually sort of look and go wow how come you're like spending less time and less money i and making more on this kind of a magic combination for encouraging adoption and some of these farmers are also bring livestock back onto their farms in terms of their ability to manure crops and there's a whole movement for regenerative grazing practices and i also visited but you know the new book sort of looks into those practices how that there are feasible and  transition but after that transition it becomes actually more profitable to far more regenerative lee storing soils globally could help us feed the world of the future exactly to help us conserve biodiversity into the future could help us sequester more carbon into the future and could help small farms be more profitable right you try to make out eric us healthier and in the end there are just an numerable silver linings yet to restarting this oil and i and i think what is so interesting about this is that all of the regenerative methods that dave was just going through they basically work because they are you know i talked about supporting and doing everything to help my immune system that i could we actually have a sort of built in health plan if you will guess for right last rites ron bored in our body and in the soil and so it's a matter of protecting and cultivating that so that it functions and works for us like it was meant right thank you so much for connecting the dots for us in this respect i hope everybody grows out and reads this it's very readable very interesting and  the same with the others i haven't seen the new book but the old book does do you know and these are very readable and very helpful and i hope it will reorient us for toward you