I collected samples for soil testing in the fall of 2019 because I figured I should get a baseline before I started intensively grazing and, also, just because it's what people say you're supposed to do? I admit though that I've never done anything with these results because I don't know what they mean! I don't know how to read them and I don't know where the levels should be. Anyone have any tips for reading and understanding soil test results? Attaching one of our results.
Deciphering soil test results
- Thread starter emilyjost
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Jeremy Huff
New member
Hi Emily - I use the UAEX soil tests for the same reasons. The soil test shows the pH of your soil (6.5) to be ideal. For, grasses we want a pH at or above 5.7. Pastures with legumes need a slightly higher pH such as 6.0-6.5. The two main macro-nutrients that are tested is phosphorus and potassium. The phosphorus on your soils test shows it be above optimum (167ppm). Anything above 36 ppm is considered optimum. A high phosphorus is very typical for pastures that have had a history of chicken litter being applied. The take home message from this reading is the site doesn't need any chicken litter or diammonium phosphate (DAP) applied. The potassium measured low (77ppm). The minimum optimum potassium ppm is 131. Potassium is valuable nutrient for plant persistence. A forage species in Arkansas that really needs potassium is bermudagrass. One reason why bermudagrass stands weaken or fail is because of low potassium. The soil test doesn't have a actual measurement of the soil's nitrogen content. The soil test nitrogen recommendation is based upon research/data from yield studies. The soil test recommends 60 lbs of nitrogen per acre. If you choose to apply the nitrogen - I would base the timing of the application solely on what your current forage base of your pasture. Warm season forages should receive nitrogen at different times than cool season forage to optimize efficient growth. We can discuss this more if needed. If you decide to apply the nitrogen and potassium at the recommended rates for this soil test....the fertilizer amounts that need to be applied is either 130lbs of urea (46-0-0) or 176 lbs of ammonium nitrate (34-0-0) per acre and 167 lbs of pot ash (0-0-60) per acre. In the future....testing for organic matter is a valuable assessment to know a benchmark prior to a grazing mgmt system too. Hope this helps. Feel free to post other soil tests if needed.
JustinM
Justin Morris
Hello Emily. Conventional soil tests like the one you posted can be valuable in establishing a benchmark, but they don't take into account the plant available nutrients tied up in soil life. Plants will more readily absorb pre-built organic compounds created by bacteria and mycorrhizal fungi than minerals in their ionic form. This is because it takes far less energy to create finished compounds from something pre-assembled than it does from something that is in a more simplistic form. This is like a car manufacturing plant where parts come in already pre-assembled like the engine and transmission rather than the manufacturing plant having to melt down the steel to create bolts, wires and other parts from the very beginning. The big picture here is that plants prefer to absorb nutrients in their organic form where the Nitrogen, Phosphorus or Potassium are complexed with Carbon and other minerals. Because of this, I've never recommended to apply ammendments based purely on a conventional soil test because there's so much more going. This is where there can be great value in using a form of soil health testing like the Earthfort test or the Haney test to help track what's going on with the availability of not just mineral elements in their ionic form, but also those that are in the organic form. The Earthfort test for instance gives you a great idea on the major soil organism populations which provides some great insight as to who's there. Also, I'd look at getting a water-stable aggregate stability test like from Regen Ag Labs in Nebraska which helps to see how the physical, chemical and biological dimensions of the soil are working together. If I had only one metric I could test, I'd have a test done for aggregate stability. I'd be more than happy to visit about this more if you'd like.
I don't know how deep you took your soil samples. It's quite common for soil samples to be taken from the top 6 to 12 inches and no deeper. If that's your situation, it's important to know that mineral concentration usually increases dramatically as you go deeper. And in a perennial pasture situation which I'm assuming is your situation, if the grazing management doesn't allow livestock to remove too much of the plant (less than 50%) and plants are fully recovered when livestock return to graze the same paddock, then root growth will continue. This allows the plant's roots to draw upon huge reservoirs of nutrients in concert with bacteria and mycorrhizal fungi. But if grazing management allows livestock to severely graze repeatedly and/or allows livestock to return before plants have fully recovered, then the root system will remain short and the high mineral concentrations in the subsoil will remain out of reach of plant roots. All the minerals your plants need are there are your property. It's just that either the minerals are unavailable because of an inactive population of soil organisms or the plant roots are not long enough to access those minerals. Grazing management is the key to moving the whole process forward.
I don't know how deep you took your soil samples. It's quite common for soil samples to be taken from the top 6 to 12 inches and no deeper. If that's your situation, it's important to know that mineral concentration usually increases dramatically as you go deeper. And in a perennial pasture situation which I'm assuming is your situation, if the grazing management doesn't allow livestock to remove too much of the plant (less than 50%) and plants are fully recovered when livestock return to graze the same paddock, then root growth will continue. This allows the plant's roots to draw upon huge reservoirs of nutrients in concert with bacteria and mycorrhizal fungi. But if grazing management allows livestock to severely graze repeatedly and/or allows livestock to return before plants have fully recovered, then the root system will remain short and the high mineral concentrations in the subsoil will remain out of reach of plant roots. All the minerals your plants need are there are your property. It's just that either the minerals are unavailable because of an inactive population of soil organisms or the plant roots are not long enough to access those minerals. Grazing management is the key to moving the whole process forward.
Matt Fryer
New member
Hello Emily,
Sorry I'm late to the party.
I'd agree with Jeremy. He knows his stuff.
However, I'd have to respectfully disagree with Justin M on some things he said, but I also agree with some things he said.
Things I disagree with Justin on:
Plant's don't take up organic compounds, but in fact do absorb ionic forms of nutrients. The report you show in your picture is very reliable regarding the fertilizers recommended. Many decades or research, man hours, and research dollars are behind the recommendations in the soil report you showed. Soil health tests are valuable to track soil function (soil health) improvements on a single field over time, but not necessarily for fertilizer recommendations. Nutrient concentration (in AR at least) do not increase as you move down the profile, but in most cases actually decrease the deeper in the soil you go. We recommend a 4in soil sample depth in AR for fertilizer recommendations in forages.
Thing I think Justin is absolutely correct on:
There is so much going on in the soil. Biological, physical, and chemical processes all play a role. His comments on root growth and proper grazing management is vital to help the soil function to it's maximum capacity. This is why we are all here!
If you'd like further guidance on your soil report, please don't hesitate to reach out. My email is mfryer@uada.edu. Give me a call at 501-671-2176. As a soils instructor for the University of Arkansas Cooperative Extension Service, helping you is one of the things I get paid to do, so don't feel like you are a bother at all.
Sorry I'm late to the party.
I'd agree with Jeremy. He knows his stuff.
However, I'd have to respectfully disagree with Justin M on some things he said, but I also agree with some things he said.
Things I disagree with Justin on:
Plant's don't take up organic compounds, but in fact do absorb ionic forms of nutrients. The report you show in your picture is very reliable regarding the fertilizers recommended. Many decades or research, man hours, and research dollars are behind the recommendations in the soil report you showed. Soil health tests are valuable to track soil function (soil health) improvements on a single field over time, but not necessarily for fertilizer recommendations. Nutrient concentration (in AR at least) do not increase as you move down the profile, but in most cases actually decrease the deeper in the soil you go. We recommend a 4in soil sample depth in AR for fertilizer recommendations in forages.
Thing I think Justin is absolutely correct on:
There is so much going on in the soil. Biological, physical, and chemical processes all play a role. His comments on root growth and proper grazing management is vital to help the soil function to it's maximum capacity. This is why we are all here!
If you'd like further guidance on your soil report, please don't hesitate to reach out. My email is mfryer@uada.edu. Give me a call at 501-671-2176. As a soils instructor for the University of Arkansas Cooperative Extension Service, helping you is one of the things I get paid to do, so don't feel like you are a bother at all.
Matt Fryer
New member
Hello Emily,
I'm still learning how to operate in this forum. Below is my response to your post that I accidentally posted separately.
Sorry I'm late to the party.
I'd agree with Jeremy. He knows his stuff.
However, I'd have to respectfully disagree with Justin M on some things he said, but I also agree with some things he said.
Things I disagree with Justin on:
Plant's don't take up organic compounds, but in fact do absorb ionic forms of nutrients. The report you show in your picture is very reliable regarding the fertilizers recommended. Many decades or research, man hours, and research dollars are behind the recommendations in the soil report you showed. Soil health tests are valuable to track soil function (soil health) improvements on a single field over time, but not necessarily for fertilizer recommendations. Nutrient concentration (in AR at least) do not increase as you move down the profile, but in most cases actually decrease the deeper in the soil you go. We recommend a 4in soil sample depth in AR for fertilizer recommendations in forages.
Thing I think Justin is absolutely correct on:
There is so much going on in the soil. Biological, physical, and chemical processes all play a role. His comments on root growth and proper grazing management is vital to help the soil function to it's maximum capacity. This is why we are all here!
If you'd like further guidance on your soil report, please don't hesitate to reach out. My email is mfryer@uada.edu. Give me a call at 501-671-2176. As a soils instructor for the University of Arkansas Cooperative Extension Service, helping you is one of the things I get paid to do, so don't feel like you are a bother at all.
Linda Poole
NCAT Regenerative Grazing Specialist
Matt Fryer, love it that you're offering direct and site-specific information to emilyjost!
And I'm always intrigued when scientists have varying views on topics. It's so helpful for us to see a wide range of science, experience, and recommendations. Thank you!
And I'm always intrigued when scientists have varying views on topics. It's so helpful for us to see a wide range of science, experience, and recommendations. Thank you!
JustinM
Justin Morris
Hello Matt. Thank you for voicing your viewpoint regarding the comments I made about conventional soil testing. While it's true that plants absorb nutrients in their ionic state especially where soil life has been devastated, conventional soil testing completely misses the plant-microbial bridge of nutrient acquisition. Dr. Rick Haney from the Agricultural Research Service in Temple, Texas has a soil test called the Soil Health Nutrient Tool (SHNT) that accounts for plants absorbing nutrients in their organic form (tied with carbon) as well as in their inorganic form. Additionally, James White from Rutgers University has shown over the last couple of years that plants will actually ingest bacteria (which are made of carbon) to pull nutrients off their outer membrane and then eject them back out into the soil so the bacteria can go and collect more nutrients for the plant, a process now known as rhizophagy. What we knew to be true yesterday is now being discovered that it's no longer true today because of researchers like Rick and James along with many other pioneering soil scientists who are leading the way. Our understanding of how plants communicate with microbes to acquire nutrients is going far beyond what we've ever understood in the past.
Prior to 2008, I looked at soil as something that had to be amended to correct supposed deficiencies. Soil was merely a chemistry set to me. My training up until that time taught me that all I have to do is follow the recommendations from a soil test and add whatever it advised to correct the deficiencies. But as I embarked on my own personal journey down the road of soil health and saw firsthand how producers who were about to go bankrupt turn their farms around without any salt-based fertilizers because they could no longer afford them, I came to realize that the biological realm of soil is far more important than the chemical or the physical realms of soil. I had completely overlooked the most important part of the soil which was life itself. Ironically, I was never taught this in the university because at the time of the early 2000s, the university was not teaching how to farm without using salt-based fertilizers. And quite honestly much has been discovered in the realm of soil science and the soil microbiome in the last 10 to 15 years. I had to unlearn what I learned earlier to make way for new information that shattered everything I thought to be true. I learned that if we treat the soil like it's a part of us as if it were an extension of our own bodies, we will do nothing to harm it including the application of salt-based fertilizers and other chemicals that hurt or destroy soil life. The paradigm of adding soil amendments to correct deficiencies is old science. New chapters from some of these ground breaking researchers are being written that provide us with information that actually puts farmers and ranchers in the driver's seat to become profitable again through a reduction and sometimes all out elimination of soil amendments even in annually cropped systems. I personally know producers who have done just that. And, in a pasture situation, my entire fertility program comes on four legs and adaptive grazing management. The cow, sheep or goat under the right management can facilitate far more change than any soil amendment ever could. To sum it all up, while a conventional soil test is nice to have, it's only telling part of the story and therefore has very little relevancy in light of new knowledge that's become available. I want the whole story, which requires that I use soil health related laboratory tests and in-field soil health assessments to know whether I'm on track or not.
I've included just two journal articles from among dozens of articles I have on file that support a soil health perspective. If you'd prefer to visit by phone, I'm totally open to that as well. I love to talk about soil health and grazing!
Prior to 2008, I looked at soil as something that had to be amended to correct supposed deficiencies. Soil was merely a chemistry set to me. My training up until that time taught me that all I have to do is follow the recommendations from a soil test and add whatever it advised to correct the deficiencies. But as I embarked on my own personal journey down the road of soil health and saw firsthand how producers who were about to go bankrupt turn their farms around without any salt-based fertilizers because they could no longer afford them, I came to realize that the biological realm of soil is far more important than the chemical or the physical realms of soil. I had completely overlooked the most important part of the soil which was life itself. Ironically, I was never taught this in the university because at the time of the early 2000s, the university was not teaching how to farm without using salt-based fertilizers. And quite honestly much has been discovered in the realm of soil science and the soil microbiome in the last 10 to 15 years. I had to unlearn what I learned earlier to make way for new information that shattered everything I thought to be true. I learned that if we treat the soil like it's a part of us as if it were an extension of our own bodies, we will do nothing to harm it including the application of salt-based fertilizers and other chemicals that hurt or destroy soil life. The paradigm of adding soil amendments to correct deficiencies is old science. New chapters from some of these ground breaking researchers are being written that provide us with information that actually puts farmers and ranchers in the driver's seat to become profitable again through a reduction and sometimes all out elimination of soil amendments even in annually cropped systems. I personally know producers who have done just that. And, in a pasture situation, my entire fertility program comes on four legs and adaptive grazing management. The cow, sheep or goat under the right management can facilitate far more change than any soil amendment ever could. To sum it all up, while a conventional soil test is nice to have, it's only telling part of the story and therefore has very little relevancy in light of new knowledge that's become available. I want the whole story, which requires that I use soil health related laboratory tests and in-field soil health assessments to know whether I'm on track or not.
I've included just two journal articles from among dozens of articles I have on file that support a soil health perspective. If you'd prefer to visit by phone, I'm totally open to that as well. I love to talk about soil health and grazing!