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Soil Sampling for Accurate Results

Bob Gregory


It's only as good as your sampling. How to get the most accurate results from your soil sampling efforts.


Bob Gregory

Owner/Director of Berea Gardens Agriculture Center in Minnora, WV



  • January 18, 2018
    9:30 AM


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The class that been asked to teach this morning is is how to take a soil sample and some of obviously many of you are familiar with. With. Utilizing soil analysis for your benefit and want to just maybe give you some pointers about how to get the best results from your soil sample because frankly the information that you get is only as good as the sample that you submit right so what we want to discuss a little bit today is what kind of information is available through soil analysis some of the methods that I use for taking soil samples and how to get the most accurate results from your soil analysis because oftentimes especially if you're growing a lot of crop there's a big investment that's tied to the information that you get from that's all analysis so that's what we're going to discuss this morning I'm Bob Gregory some of you may have heard a little bit about me last evening when when I was introduced but I've been working in agriculture for over fifty years and the majority of that time I served as a crop consultant out in the western states and in Latin America and over the course of time I've probably taken thousands of soil samples and. The technique that we use and the methodology that we use is very important to getting good results I'm going to talk about a few other things in the course of the discussion this morning and for more information about anything that we do or if you have interest in looking at some videos that that go into a deeper discussion of some of the topics I'm going to touch on this morning make a note of our web address here if you would. Be a garden stud or gee there are some video downloads some Powerpoint. Presentations on there they can be very helpful discussing some of the aspects of what I'm going to talk about this morning that we're not going to have time to go in too deeply before we start this morning let's have a word approach our. Father in heaven we're grateful for the liberty to come together here and to discuss this topic of agriculture with thankful for the commitment of all the people that invested their labors in organizing this opportunity and I pray that your Holy Spirit will be with us today and all that we say and do that you can lead us to the truths that will help us to understand how better to fulfill your desire that we work with the soil abide with us now I ask in Jesus' name and we're exercising a little bit here to see if my clicker is going to reach where my computer is in the back of the room and I haven't used it over a distance like this so I may struggle a little bit with advancing slides for you but this is a picture of our farm we have about one hundred twenty acres in West Virginia where we purchased a farm and after we bought the farm the Lord provided us with an abandoned school building that was adjacent to our farm and that is Bria gardens are training center and our market farm of the hundred twenty acres I actually cultivate a little less than three of those acres for our market farming purposes we have fruit trees we have small fruits we have berries blueberries raspberries blackberries and we grow the majority of our food on this side as well as supporting ourselves with market farming. Up until just recently my daughter was at home helping me with the farming for the last two years I basically am doing it on my own and part of our reason for staying small like that is because we want to encourage those of you that have an interest and. Supporting yourselves and the country lifestyle through agriculture with a demonstration farm that is actually family scale we don't have in turns we don't have volunteers there are occasional times when there's a heavy workload where I will bring in a couple of the young people from our community to help me for a day or or sometimes two days at a time with harvesting some things but the majority of the work is done by these two hands and we're able to support ourselves doing that and this is part of our objective is to demonstrate that it is possible to earn a living from the land even in these times now. Get a I'm sorry I've got a failure on my computer here. And there we go. With my background in agriculture I have gone from a very large scale to a very small scale but I have found that the rewards at the smaller scale are far greater than the rewards that I had at the larger scale and it doesn't have to be big to be successful. The reality today with economics being what they are with the interest in the local food movement that is taking place around the country it's conceivable to earn between thirty and fifty thousand dollars per acre of cultivated area and that's a pretty you know. Substantial income compared to the costs of operating an operation that small there are great efficiencies that you have in small scale agriculture that don't exist in larger scale agriculture and because the cost of oil is so high and the cost of of farm inputs for large scale agriculture have become so high we've reached a point where I can produce organic produce. On a small scale and market it and still. Still find a profit margin. And in doing that even competing with the large multinational corporations one of the things that I want to mention this morning it's a little bit off topic but I'm again can we advance the slide please. One of the things that I want to mention this morning also is that in agriculture today as I said last night there are a lot of winds of doctrine that are blowing about and my philosophy after all of the cum complex situations that I've found myself in over fifty years is that simpler is indeed better I honestly believe that the simplest way that we can do things the most efficient we can be is by far the best that we can be and in that sense there are many winds of doctrine blowing through agriculture today that I think deviate. To some degree from what the Lord's intention for us was when he put us on the garden you know in Genesis three twenty three he he tells Adam two that he's he's banished from Eden and he has to go out and till the land from whence he came that word tilled is an important word I believe and there are many methods and and various different strategies for producing crops today that don't fit that criteria so I'm a traditionalist in that sense and I believe that it's important for us to work with the soil that it's important for us and economically this is sound also that if we do it properly and if we do it appropriately then many of these other methods of agriculture that are being utilized today are really kind of outside of that biblical model hydroponics for example is one very popular method for growing crops because you don't have to get dirty doing it and you rely very heavily on all kinds of mechanized systems and inputs that cause. Costs for stablish in an operation hydroponically are very very high and you're totally reliant on systems that are beyond your control I don't feel that that's the way the Lord would have us to garden I don't feel that that's the way the Lord would have us demonstrate to the world the blessings that can be found when we start cooperating with him in working in the soil Biodynamics is another kind of catch phrase that's out there right now about using all kinds of natural him puts into your garden I'm not opposed to actual natural inputs but the Biodynamics is is really a methodology that can mean whatever you want it to mean we're biodynamic just means that life is active and you know it's sells a lot of books if you want to make money in agriculture by the way the best thing to do is to not worry about growing crops just come up with a methodology and write a book because there are a lot of people that are interested in agriculture right now and growing food and doing something different from what we know the toxic common method for producing food is and everybody is struggling and looking for a new idea and they will follow one method for a period of time and if that isn't successful and they're looking for them for another method and they're constantly looking for that missing piece of information that has you know has not allowed them to be as successful as they would like to be aqua culture also is a bit of a problem these days Ocracoke sure is a method of utilizing fish production in combination with agriculture where you. Where you basically farm fish in and waters that are then used to irrigate your crops there are a lot of problems with that from a phytosanitary perspective especially if you're growing things that will be consumed raw there's a lot of biological waste product in that that can get you into trouble with the Food Safety Modernization Act and. It's just not a viable alternative to to working in and telling the soil. Perma culture is also a term that you're probably familiar with it's become very common today for gardeners to go to basically you know till system in their gardens where they lay down various different layers of of organic material and instead of telling that organic material on one crop is completed it simply replanted with another crop that's a recipe for disaster in the long run and realistically it's not a practical way to get to achieve excellent production if you to advance the slide please. What I have learned over time is that working with our soil is a process of building the soil really into steps and the soil analysis is useful for both of these purposes but one of the ways that I I apply the information of a soil analysis is very very different than what mainstream agriculture does typically when we take a soil analysis we think what we're looking for are basically the nutrient elements in the soil correct isn't that what most of us are interested in how much nitrogen do I need how much phosphorus do I need how much zinc do I need to apply Well I kind of take that whole paradigm and stand it on its head and use an aspect of the soil analysis very very differently than the soil scientists do and I'm going to get into a little deeper explanation of that but before we analyze our soil one of the things that's helpful especially if you're working with a new soil which you advance a slide please. Is to know some of the characteristics of the depth of your soil profile. And I presume that since you are gardeners that you're aware that soils across the country vary tremendously not only in their physical characteristics but also in their depth this is a map of the major soil borders of the United States here on the slide each color represents a really entirely different order of soil and with each of these within each of these orders there are hundreds of different soil types so what. We can use as a tool advance the slide please what we can use as a tool to help us understand something about the soil order separate and apart from the chemistry of the soil is some information that's been gleaned over time since the dustbowl air really when the U.S.D.A. undertook to do a Soil Map of the entire United States and there's information available to you online through this website website all survey dot and R.C.S. dot U.S.D.A. dot gov that can give you a representation of the Soil Map for your individual property and the saw maps are amazingly accurate to me they were initiated back in the one nine hundred late one nine hundred thirty S. by men with with soil probes and shovels and boots on the ground and it was actually completed by the space shuttle. Using methods of. Radar and other techniques that they had infrared scanning that they were able to complete this oil map for the entire country and it gives us some of the physical characteristics of the soil it tells us how deep the soil is too or restricted barrier. Like a hard pan or a. Stone shelf limestone tells us what the the rate of water penetration is in each of these soils and it can give you some potential. Soul comparisons between one soul type and others far as productivity it's really useful tool I have made use of this on our place for example to determine where to plant our fruit trees on the surface of the soil the soil looks very much the same there is very little difference but because of the information I was able to glean from this I came to understand what was taking place six feet down in the SO I don't have a backhoe so I wasn't able to dig that deep and I wasn't energetic enough to dig a hole that deep but I was able to do some comparisons between the soil types on my property and find where the location was where I would have the best drainage for my orchard and these are ways that this myth information can be applied that's very very useful. No slide please. Excuse me. One of the first things I want to you know discuss with you this morning is what is soil what are we talking about when we take it so well sample and essentially soil is a ratio of minerals air water and organic matter and when we take a soil sample what we're actually analyzing is what the mineral content is in the soil now the mineral content only makes up about fifty percent of most soils. Almost a quarter of what we're walking on women are walking around out here is air and another quarter of that is water so fifty percent of soils are air and water and this is a ratio when the soils are actually growing crops actually producing something obviously there are periods of time when it's more saturated than that and the air and water ratios move back and forth. As soils dry and are wet it and the organic matter in most of the soils that we use for gardening this is. Awfully three to five percent I prefer to keep my soul's up in the four to forty five percent range but that's very adequate and very very productive for most soils there are a few soil types where the organic matter can be much higher than that that's not necessarily an advantage if you don't have the right mineral content in the soil to over time that organic matter re mineralize is and adds to the mineral content of the soil but having a real course amount and large amount of organic matter in your souls is not really the best for plant roots you need a good balance of mineral content in there and this ratio is about ideal for growing most crops slide place. The things that we learn from a soil analysis are essentially these. We can learn from the saw analysis what the percentage of organic matter is essentially this is done by firing the soil sample and turning everything that's organic matter into carbon So essentially what you're measuring here when you're measuring organic matter is you're measuring how much carbon is in the soil that's on a good soil report it will tell us to some degree the texture of our soil how much sand how much silt and how much clay is in the soil and this is actually reported in a way that is not spelled out for you very clearly it's it's reported in something called the C.E.C. which stands for cat ion exchange capacity and I'm going to get into a little deeper explanation of that here in a moment but that number that is given as a C.E.C. gives you an indication of how course or how far in the soil is many people tell me for example that they have a clay soil when I look at their soil analysis and I can look at that number first C.E.C. and realise that they don't. Much clay at all in that soil even though they perceive it to be clay because of the way that the soil particles are formed. And to give us an indication of the ph of the soil the acidity or the alkalinity of the soil and this is an important thing to understand and it gives us a good soil analysis gives us two methods of measuring some of the major plant nutrients one is called the. Base saturation and those are elements that are actually kind of magnetically or are electrically bonded to the mineral particles in the soil and then it gives us an overall picture of how much of that mineral is in the soil and that's reported in parts per million typically some soil reports is pounds per acre I prefer to use a lab that reports in parts per million because pounds per acre. That particular measurement is predicated on the fact that you're only sampling six inches deep and in my SO I like to work my swells a foot deep spirit of prophecy indicates that we should plow deeply that's one of the whites statements to us and she gives us a little bit of a definition of what that plow deeply means in. A description of a vision that she had at Avondale where the Lord opened up a furrow of soil and she described that for as being a quarter of a yard deep which is nine inches and by having a deeper. Analysis of your soil and working your soil more deeply particularly the the way that I farm where I grow very intensively it gives a much larger reservoir of nutrition a much larger area that is is available to the root systems of plants to produce and to produce abundantly. The other advantage of. The soil analysis especially if we're fine following protocols. To try to achieve a given result as we can determine from the SO analysis exact targets for the mineral applications that we want to make to that soil to bring it into balance many people resist. Analyzing their soil and I think most of that resistance is just based on the fact that most people don't know what to do with us on Alice S. and you have to rely on someone else to interpret it for you and that can get a little bit complex because there are a number of different ways to analyze soil too and I'll cover some of that this morning next likely. One of the things that's reported that's important to us is the PH of the soil most of us have heard this most of us understand that our crops for ideal growth like a ph range between about six point seven and neutral at seven that's excellent for most crops part of the reason for that next slide please is that it has to do with nutrient availability and the slide here will give you an idea of what I'm talking about what's reported on this slide here is at a given amount of nutrient. Each element here and a given quantity has a different availability based on the ph here so for example if you have a given amount of iron in your soil the more alcohol in the soil becomes the less is available Similarly if you have boron in your soil. At a given amount the PH impacts the availability of the boron and with things like phosphorus which is a primary nutrient this becomes pretty important because phosphorous is is very important for plant growth it's also expensive if you need to apply at and if you're applying phosphorous in your PH is down in the range of five and a half or so you're getting very very little efficiency out of it so that's one of the reasons that we pay such close close attention to the to the P. H. Next slide please. And agriculture there are three primary soil chemical classes. The dominant soil class that's used for agriculture around the world are considered acid soils these are soils that have a Ph below seven they have free hydrogen in the base saturation and I'll explain what the base saturation is here momentarily and the vast majority of soils in the world that are used for agriculture are acidic soils even here in Texas where you have light colored soils oftentimes with lots of calcium in them you can have free hydrogen in those calisthenics wells and still have an acid condition. Cal carious oils is the second classification these are the soils that are generally the most productive in the world the area that I came from. Northern Sacramento Valley and the Central Valley of California the Salinas Valley and California famous for its agriculture these are examples of calque area soils as well as the world lamb and Valley in Oregon. Calcareous soils contain calcium and magnesium carbonates and they often contain a quite high levels of phosphates and these are the most fertile soils in the world and used for agriculture the last classification here the Sodexo oils these are highly alkaline soil so usually with a ph above eight. They have a lot of sodium in the base saturation rather than hydrogen they tend to be very poorly drained even if they're very coarse soils even if they're sandy soils and they are very high in ph water does not penetrate very well that's why we see oftentimes you know such dramatic flooding after thunderstorms even out in the desert states of New Mexico and Arizona that's because the water can't get in. Into the soil and that's a chemical barrier in the soil rather than a physical barrier to the water penetration they tend to be very poorly drained also and these are found mostly in arid and semi-arid regions next live place. So my suggestion to gardeners if you're serious about growing things at all is first and foremost your first step should be a soil analysis let's see what we're working with if we're not going to make the investment of a soil analysis all of the other investments that we make in our gardening are potentially going to be inappropriate and the reality is that a good quality soil analysis and that the laboratory that I like to use as an L laboratories or nationwide system of laboratories is only fifteen dollars or less and for that fifteen dollars I get more information than even me as a skilled agronomist with fifty years of experience could get by observing the crops growing for a period of three or four years it would take me a long time to understand all of the chemical characteristics of that spoil simply by growing crops and observing the crop response to the minerals that are present there so it's a very good investment and I suggest that you use a reputable privately run soil laboratory many of our state AG programs and extension services offer very inexpensive or even free soil analysis and I suggest that you don't rely entirely on that simply because those are training programs for soil scientists those are laboratories that are are publicly funded that may not have the latest equipment and oftentimes because of the difference in paradigm that I mentioned on how I use a soil analysis you don't get. Complete information from a state lab there are a few exceptions is that University of North Carolina has an excellent soil laboratory and Cornell also has an excellent soil laboratory but for the most part most of our states simply can't compete with the quality of the soil analysis that you get from a privately run laboratory and privately run laboratories also have a much higher incentive to provide you with accurate results if they are analyzing. Soil samples from a five thousand acre farm and that farmer is making his economic investments based on what that soil analysis tells him if the lab is way off the mark it's going to cost him a tremendous amount of money over time so their level of accountability is quite a bit higher if they want to stay in business. Be certain absolutely certain that whatever laboratory you choose to use has a component in the soil analysis called base saturation that's actually the most important information that you'll get from a soil analysis and as I said I'll give you an explanation of that here in a moment but if a if a lab is just reporting to you elements in parts per million you're not getting all of the information that you need. The slightly have OK. The other thing that's important to understand is that there are different ways that laboratories extract elements from your soil sample and this extraction method is really important for you to be aware of because the results of your soil analysis are going to be predicated on the extraction method that is used for example some of you have probably been Mars soil classes and you know with more understands what he's teaching very very well and he is looking at a soil analysis that is different than the model of soil analysis that I use his perspective and my perspective are we don't disagree with each other we just have a different perspective in the use of that analysis and the analysis that Whitmore uses is an analysis that gives essentially a snapshot of what's in that soil and what's available to the plant at that moment and he uses typically an ammonium acetate or a Morgan extract and the analysis that I use is the Melich three extract which is going to give me a broader picture a deeper picture of not only what's available in the soil at that moment but what potentially is available to be released in that soil from the mineral content and the different extraction methods or Bray which is used primarily for Cal carious oils with a P. H. of seven point three or higher the ammonium acetate or the Morgan extraction which is a very low acid extraction that's used for container gardening most nurseries use that form when they're when they're you know adding nutrients to the potted plants because they. I need to know what's there and available to the plants but plants are going to be in those pots for a long period of time and these are our more readily available water soluble nutrients that you're looking at the melike one extract isn't really used very much anymore most of it is gone into the two it's called the Melich three and the Melich three is ideal and my perspective for acid soils and for soils with a ph below seven point three And the reason that I use this melike extractor I use a laboratory that utilizes the Malak extract is because part of my paradigm for growing crops is that I want rich organic matter in the soil I want active organic matter I don't necessarily want more than five percent organic matter but that organic matter if it's a living organic matter can really enhanced that capacity to sayable eyes nutrients that are tied up in those mineral soil particles that wouldn't show up in a brain analysis that wouldn't show up in a morgue an extract you follow me you understand what I'm what I'm trying to convey here. On a very very high ph soil if you're eight or above then I recommend using what's called an also an extract and that also gives you a better representation of what's available in that soil over a period of time if your soil ph is very high so I understanding the extraction method is really important someone was showing me a soil analysis at lunch yesterday and I wanted to. Get my opinion on it and I looked at it and there was no indication on the analysis itself of what method of extraction they used so that was useless information to me because I beg your pardon. You can you can call the laboratory and most instances commercial laboratories will tell you when you fill out your form to submit your sample what analysis method they use this particular lab didn't do that and. Because of that those numbers were were quite literally meaningless to me so the extraction method is important and my preference particularly for acid soils or low ph soils is as for what's called the S three M. package from a in a laboratory this is a fifteen dollars sample I've used in all laboratories over the course of thirty years or so I've been very satisfied with the quality of their results their laboratory protocols are very good they're also one of the least expensive labs to it's probably one of the largest labs serving commercial agriculture in the country today. Next slide please. Another component of this so that's really pretty important along with understanding what the mineral analysis is and your soil is understanding what your salt texture is and I want to just give go over this briefly but Sol texture is simply an explanation of the particle size of the minerals in your soil the particle size of the minerals in your soil is what we call soil texture and this falls into three categories in this graphic up here is actually a two scale representation of these three. Particle sizes when you say you have a clay soil doesn't tell me anything about the chemistry all it tells me is is something about the particle size and. Particle of sand is obviously very large most of us are familiar with that silt particle is significantly smaller than a sand particle and a clay particle is infinitely smaller than a sand particle so. The particles in a given volume of soil can vary tremendously in their quantity and the numbers of particles within that volume of soil and this has a very big impact on the potential for that soil to hold nutrients clay soils are actually the best soils to farm and when people complain about the clay in their soils I just kind of shake my head because there are ways to manage some of the strategic problems of dealing with that because Clay is heavy and it's tough to work with but potentially as far as holding nutrients is by far better than sand. We look at a soil analysis and we can determine to some degree what our soil texture is from the cat on exchange capacity and in the next slide I'll explain that but most soils are not one hundred percent sand one hundred percent sold or one hundred percent clay they're a combination of those three different particle sizes. And this triangle here indicates the most productive soils to be in this part of the triangle This is one hundred percent clay here hundred percent sand hundred percent still somewhere where we have a relative balance a little bit leaning towards the silt is where the most productive soils are. Now the sole particle size is important because these particles have an interesting property Next slide please. And that is that mineral particles in the soil have a slight negative electrical charge and this slight negative electrical charge determines what we call the C.E.C. or the cat our next exchange capacity because positively charged ions can attach to those negative soil particles and the size of the soil particles determines in a given volume of soil how much elect charges there you follow me. And that electrical charge is going to be important here in just a minute next slide please now one of the ways that you can kind of get an idea to what the soil texture is is by what we call a jar test just take a pound of soil put it in a court jar fill it up with water shake it and let it stand for about twenty four hours and what will happen is it will segregate and in this particular example here at the bottom of the tape is where the lines are of the segregation This is the sand down here the larger particles settle out first this is the silt from here to here and this is the clay that's in the top layer here now if you let this stand long enough this water will actually become clear up here this is. Hasn't really stood long enough but using that method you can kind of determine what your percentage of sand silt and clay is to it in a very coarse way. Now much of what I do in analyzing a soil analysis. Has to do with some work that was done by this gentlemen and those of you that are our. Experience gardeners here probably heard of Dr William Albrecht he to me was far ahead of his time he had some prophetic insights into how to understand and comprehend the role of soil and not only plant nutrition but also animal and human nutrition and Dr Albrecht focused on an aspect of the soil called the base saturation and the Catalan exchange capacity that I make use of today and rather than looking simply at the mineral nutrients that your plants need to fertilizers He looked at the overall fundamental chemistry of the soil in terms of its ability to provide habitat for microorganisms and to facilitate. Chemical reactions because of the microbial activity in the soil that liberated nutrients and made those soils both productive and provided for greater health for both animals and human beings and in the one nine hundred forty S. He wrote this statement at the bottom of the slide and unfortunately mainstream agriculture still hasn't grasped this concept he's largely been marginalized in part because if we follow his method we're going to be making some investments in our soil that are. By commercial standards quite costly and the rate of return is not always predicated on the input to the soil because farmers that are growing corn in Iowa get paid per ton of corn they don't get paid per ton of nutrition and Albrecht's concept pushed us in the direction of thinking about how nutritious that product is rather than just how much volume was there so his work has largely been marginalized Fortunately it's been taken up in the last ten years or so and more people are paying attention especially. Small scale growers are paying attention to what we were able to learn from him and in the one nine hundred forty S. he made this statement at the bottom of the page and I just want to read it to you because it's a pretty profound statement N.-P. K. formulas that's nitrogen phosphorus and potassium as legislated and forced by State Departments of Agriculture and also mainstream agriculture I mean malnutrition attacked by insects bacteria and fungi we'd take over crop loss and dry weather and general loss of mental acuity in the population leading to degenerative metabolic disease and early death. Pretty pretty strong statement and this was written back in the forty's We've seen any evidence of this and recent times and you know so anyway he's one of my personal heroes and I've not only say that because I value what he said but I value what he did and that by following his methods I've had excellent results across the board in all of the agricultural enterprises I've been involved in. Next slide please. Now what Dr Albrecht's great contribution was remember we talked about those old mineral particles of soil having a slight negative charge well. There are positively charged ions in the soil that. Are plant nutrients and that our other constituents that are attached to those soil particles calcium magnesium potassium hydrogen in acid soils sodium in alcohol and soils are attached to the soil particles and Dr Albrecht's great contribution was determining how much of each of these should be attached to those soil particles and that's what's expressed in that term base saturation on the soil analysis will we see that term base at your ration. It's talking about these elements that are bonded to the soil particles and getting the right ratio of this and our soils is really what lights the fuse for all of the activity in the soil biologically including plant roots and plant growth but it is a critically important factor in converting the other nutrients that plants need into a form that's available to plants too so it's the catalyst this is the most critical step is dealing with this base at aeration Next slide please. Now if you want some more resources about that explain this there's a free download on my website this is about an eighty minute Power Point presentation that I did for a country living university that goes through step by step how to apply Albrecht's principles to your soil analysis and if you go to Berea gardens dot org You can you can find us there's also another interesting video here called the other side of the fence this was actually produced back in the forty's and as Dr Albrecht himself explaining in expressing some of the challenges that we have an agriculture because we're not nourishing the soils properly. Next lie place. So on our soil analysis what we should have are two representations sometimes of the same chemical element and you probably notice this if you've got a soil analysis from a lab that reports both of these things the base saturation is those calcium magnesium and potassium atoms that are act or elements that are actually attached to the mineral particles in the soil that's reported in a percentage for every hundred soil particles if I have sixty eight calcium ions attached to them that might be a saturation would be sixty eight you farming. The parts per million measurement of calcium includes all of the calcium that's in that total volume of soil because there are minerals in that soil that are not attached to the soil particles in the way of the biological material that's and that's well. Aspects of calcium that are in the soil solution and floating freely between the soil particles so that's the overall picture of the total amount of calcium that's in that soil whereas the base saturation gives you an indication of how much is bonded to the mineral particles. And it's very important to have a soil analysis that gives you both of those numbers. OK Next Slide place. This is an example I know you can't read the numbers up here on the slide but this is an example of a saw analysis that I use and down here in this corner you can make this out this says percent they saturation This tells me the percentage of calcium magnesium potassium in hydrogen that's in that soil that's critically important to know in order to manage your soil properly up here on the top line we have potassium magnesium and calcium reported in parts per million those numbers report different things. And I just want to clarify that because we need to understand that making use of your analysis you can't simply look at the numbers in parts per million up here and deduce what is down here so those are the two elements of a song Alice's that are critically important. Next slide please. OK this is just go ahead to the next one to please. Just to reiterate OK Now most of us are aware of the plants need seventeen essential elements to survive and to thrive This is the basis for hydroponic agriculture by the way those of you there I see some of you taking photographs I just want to make you aware I haven't supplied them yet but these this actual power point will be available. On the Agora website probably in the next day or two so you'll have all of these availability there are seventeen essential plan nutrients and most of these are reported on most soil analysis but a couple of them aren't and I just want to mention that so that you don't think you're getting an incomplete analysis when you get it from the laboratory if you use the one that I suggested the S three analysis for example they're not going to report how much molybdenum is in the soil and one of the reasons for that is they haven't developed a really accurate test for molybdenum So it's generally not reported molybdenum is usually. It's rarely deficient in most soils I'm not going to say it doesn't happen it doesn't times but it's easier to diagnose that from plant growth rather than it is to take a soil sample for molybdenum it's not a particularly accurate analysis the other one that won't show up on your soil analysis is nickel and that's because nickel is used and such tiny tiny amounts that there are no known instances on the planet of nickel deficiency it's just doesn't. Exist because it's so you know it's used in such such tiny amounts some. Labs will report Cobalt as an essential nutrient Cobalt has not been as stablished as in the central nutrient but Cobalt does have an influence on the availability of molybdenum in the soil so I put that on here just to clarify that yes Cobalt does have an effect on plant growth but it's not an essential nutrients. Next slide please. All right now one of the things that I have come to understand and you know last night I mention that I'm often stunned by what we don't know about agriculture is that we know virtually everything agrah nomic lay about those seventeen essential elements and how critical they are to agriculture and how to apply just the right NOW amounts at the right time and to get the right ratios but the problem is that human beings require at least fifteen additional elements for health. We need fifteen more and those are the ones with the asterisk here and there's not a soil analysis on the planet that will give you a soil analysis indicating. The quantities of those fifteen elements and even if we had that information we wouldn't know what to do with it because the blindspot an egg or nah mix today is that these are not even considered as important agriculture. Now it becomes important to me when I realize that over time Next slide please. Over time these plants that were that were growing mine these minerals out of the soil they're taking them up so even if initially those other fifteen elements were in the soil on last were replacing them unless we're addressing the fact that we're removing them we're not. Growing plants that can provide complete health now even though the plants don't use those fifteen elements they get piggybacked into the plant with other chemical compounds they take these elements out of the soil in the form of compounds and can become part of the plant tissue in feed you and I or the animals that meat eaters might be but without addressing this what that means is we are continually dropping in these elements in the soil and this is one of the reasons why food is so much less nutritious today. OK would you skip the next slide please and go to the to the following slide. All right so how do we take a soil sample I see we're running out of time here and that's what you came to here how do I take a soil sample that's going to be valuable to me and the first step is to represent the root zone accurately and what I mean by that is if we're going to be farming a foot deep as I do I want to sample that represents that whole foot I don't want to just scratch the surface and grab something off the surface so I dig a hole that's a foot deep that's my first step as I scrape away hold questions till the end if you will and I will answer them but it's better if we do it at the end. I want to scrape away the top two inches which is basically most of the organic matter and get a representation of what that mineral content is in the soil so I use a clean shovel and I dig a hole a foot deep so I also want to represent the area accurately so my first study is to look at the ground and to see if there are variations in the soil itself or whatever area I'm sampling whether it's a fifty by fifty foot garden or a five acre field if there are obvious visible differences in the plant growth in the texture of the soil and the color of the soil I'm going to sample those areas differently and treat them differently. The other thing is that we want to use clean instruments when we sample I use a clean shovel when I dig my hole a foot deep and basically that's what I do is just dig a hole a foot deep nice round hole. And I want to sample the soil that I'm on moderate temperature I don't want to do it when it's really hot and I don't want to do it obviously when it's frozen. That gives us a better indication of what the actual mineral balances in the soil because biological activity has an influence on that and that fluctuates when it's hot and that's coal. And I want to sample at moderate soil moisture it's best not to sample when it's really really dry and it's best not to sample when it's saturated or really really wet and you know the criteria that I use is if I dig some soil and I squeeze it together if there is free water coming out of the soil as to saturated if it sticks together in a clump that's just fine and you can sand wet soil to the laboratory their first step is to actually put it in an oven and dry it out so it's OK to set with send with soil to the laboratory. And I use a composite sampling method meaning that in those areas that I'm going to sample I'll dig two or three or four holes and take a small amount of soil of each of those from each of those holes and combine them together this is a very important step you never want to just select one spot for your soil sample and why is that it's because there is tremendous variation in the soil and if you happen to pick a spot that the birds flew over the night before and and bombed you're going to have you're going to have the influence of that waste matter in your soil sample that isn't present in the rest of the field so it's really important to use a composite method for sampling and essentially all I do is I take a shovel I dig a hole a foot deep and about a foot in diameter I take out a clean stainless steel table spoon and I started to. Bottom of the hole and I scrape a little soil all the way to the top of the hole and get a tablespoon full of soil and I put that I just use Ziploc freezer bag to put the sample and and I'll do that in three or four places within each hole that I've done and combine that together so that I have about a pound of soil which is about as much as your fist and that's what I sent to the laboratory and that has provided me with results that are excellent Now there are other tools that are good that are being sold today so I'll probs where you can just poke down into the soil and pull it back out have a nice little plug of soil I don't suggest using those on a small scale I did for many years when I was taking fifty or sixty soil samples a day but the reality is that you know most of our soils that we're gardening with are not stone free and they're not really fragile soils and it's hard to get one of those a foot deep if you're going to be sampling deeply too so the keep points I want to make is trying to represent your soil as clearly as possible and that means depth and also area so if you do that you'll get a sample sent to the lab that can be made very very useful to you understand the method of analysis that's being used and for those of you that want to learn and understand more about that and come see me back in the corner we've got a table in the back there and we do offer training programs on how to go through a soil analysis and and we have lots of information available about that So with that I'll conclude I think we're probably out of time. And I want to say thank you very much and blessings to you all are there any questions yes or. No How do I clean my tools so they don't have residues you don't like. And some soaps might leave a residue but the solution to. That is just to rinse them very clearly and you know very very thoroughly in most instances you're not going to to skew your results real significantly and it doesn't have to be a sterile tool just just clean can the plastic bag influence that any in some instances yes I use food grade Ziploc bags for the samples that I submit some laboratories will provide you with a waxed paper bag or if your soil is dry enough a paper bag is also suitable but something like a trash bag or you know something that's designed for some other product can leach some chlorides and other things into the into the sample the other thing that I should mention too is you want to get your sample samples to the laboratory quickly don't you know leave don't throw it in a plastic bag and leave in on the see your pick up truck for two weeks and then send it in so you want you want to do it promptly. I scraped the side of the hole yes yes or. I do not the question was he heard the by telling deeply you get anaerobic bacteria from from deep in the soil profile and you exchange that with your robot bacteria on the surface when you flip the soil over the reality is that the environment in the soil at a foot deep as not a whole lot different than it is at the surface you still should have lots of the air in that soil and the bacterial populations are not going to be significantly different I would disagree with that statement. Yes ma'am. If you don't plan if you don't plan to for two to till your soil a foot deep can't can you invigorate the soil deeper than the six inches that you're working is that my understanding. OK yes there are there are ways to use chemistry to help accomplish that as well as crop cycles but I think we're out of time so if you'd like to talk about that alone more I will. Yes. Well all the. Sample where the roots are is what I will say if the roots aren't there don't sample there OK. I'm sorry sir. The volume of the sample should he asked what the volume of the sample should be each sample should be about a pound of soil and that's about the size of your fist. One last question that will have to close. When is it appropriate to retest that's an excellent question and one that's beyond the scope of this class because it really is based on what your results what your initial results tell you and what courses of action you follow after that as a general rule of thumb I sample about every three years but there is reason for that and I can't say to you to sample every three years so it's all predicated on what the results of your sample are and what courses of action that you have taken. So there's no pat answer to that. I'd like to thank you all very much it's been a blessing to have you in the prayer you all have excellent success You're very welcome. 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