The Garden Thyme Podcast
A monthly podcast where we help you get down and dirty in your garden, with timely gardening tips, information about native plants, and more! The Garden Thyme Podcast is brought to you by the University of Maryland Extension. https://extension.umd.edu/. This institution is an equal opportunity provider.
The Garden Thyme Podcast
602 Soil Amendment & Fertilizer with Andrew Ristvey
Hey Listener
In this month's episode, we are joined by Extension Specialist in Commercial Horticulture, Dr. Andrew Ristvey, to discuss the in and out of soil amendment & fertilizers. We cover the benefits of amending your soil, the difference between an amendment & fertilizer, what are the different types of Nitrogen fertilizers, how to adjust soil pH.
As always, it is always a great time to get a soil test to help tell you how to amend your soil. For more information about soil testing and to find a soil testing lab near you, check out the University of Maryland Extension Home and Garden Information Center soil testing website. (https://extension.umd.edu/resource/soil-testing-and-soil-testing-labs/), or check with your local extension office.
- University of Georgia Fertilizer Calculator: https://aesl.ces.uga.edu/soil/fertcalc/
- Purdue Turf Fertilizer Calculator - https://turf.purdue.edu/fertilizer-calculator/
- Maryland TT-115
We currently have an open survey for ALL listeners. Whether you’ve listened to all of our episodes, or this is your first time. We developed an evaluation to determine if the information we share on the podcast has made a difference in your practices at home. We promise that it is a short, easy 5-minute survey, and we even have exclusive podcast stickers to give to those who participate. We are so thankful for the feedback, and we appreciate you tuning in for the podcast!
The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Principal Agent Associate (Talbot County) for Horticulture; Rachel Rhodes- Senior Agent Associate for Horticulture (Queen Anne's County); and Emily Zobel- Senior Agent Associate for Agriculture (Dorchester County).
Theme Song: By Jason Inc,
University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class.
Garden Thyme Podcast Transcript: S6:E02 602 Fertilizer and Soil Amendments with Dr. Andrew Ritzvry
Note: The Garden Thyme Podcast is produced for the ear and is designed to be heard. If you are able, we strongly encourage you to listen to the audio, which includes emotion and emphasis that's not on the page. Transcripts are generated using a combination.
:Up Beat Music:
Rachel
Hello, listener. Welcome to the University of Maryland extension presents the Garden Thyme Podcast, where we talk about getting down and dirty in your garden. We're your hosts. I'm Rachael.
Mikeala
I'm Mikaela.
Emily
And I'm Emily.
Rachel
In this month's episode, we're talking about Fertilizer and Soil Amendments with Dr. Andrew Ritzvry, the University of Maryland Extension Specialist for Commercial Horticulture.
:Up Beat Music:
Emily
Well, thank you for coming on the podcast, Andrew. Again, you were here... Oh, what? '21 or '22, I want to say you came on to talk about pruning.
Andrew
It's been a while.
Mikaela
Needless to say, it was time to bring Andrew back on the podcast
Andrew
It's a pleasure being back with you three.
Rachel
We I love having you here because, A you're full of knowledge, and B, this is a topic that we get a ton of questions about. I think it will help people, especially coming into the growing season, to hear a little bit more about maybe what they should be looking for, what they should be using, where, and all of those details.
Andrew
Sounds good.
Emily
Andrew, what are some of the benefits of amending our soils?
Andrew
Well, amending a soil, certainly Secondly, I think the chief benefit is to ensure that the soil is perfect for plant growth and root growth. We're amending soils primarily to either change the fertility, to add fertility, to add any particular nutrient that may be missing, and to better the physical properties of the soil, especially if we're adding organic materials. We might want to add amendments to change the chemical nature of the soil, the pH, of course, whether it be liming to raise the pH or some acidification material like sulfur to lower the pH based on what we're growing. Most plants like PH of 6. 5, but there's some plants that need a PH of between 4. 5 and 5, like our azaleas, our strawberries, and our piedras. Depending on what you need in that soil to make sure those plants are healthy and growing well, you need to add an amendment to ensure that your soil is the right environment for the plant you're growing.
Emily
Perfect. Everybody's always in search of the perfect growing conditions.
Andrew
Yes, exactly. That the perfect loom What's the difference between fertilizer and amendments?
Mikeala
Because I think often we mistaken the two for one another or they get mixed up pretty easily. What would be the most generic way to distinguish them?
Andrew
Well, the thing is, it's like a logic model, or should I say, they can be either. If you're amending a soil, you're trying to fix it, right? So my interpretation of the two terms is that they're very similar in effect. So if you're applying an amendment, that amendment could be a fertilizer. And if you're applying a fertilizer, then that fertilizer could be an amendment. I think they're synonymous in terms depending on what you're applying. And maybe you need to go back to what the definition of a fertilizer is and then try to distinguish things that way. So I guess let's start with the basics of what a fertilizer is. And even before then, you need to know what nutrients are and what they do for the plant. There's 14 mineralized nutrients that plants require. They're called essential nutrients, and they're all involved in fertility, soil fertility and fertilizing the plants themselves. And any material that may be supplying any one or several together of those nutrients could be considered a fertilizer. That's my opinion anyways. It's arguably. And so a lot of the amendments that we apply, whether they're a mineral amendment, like let's say gypsum or epsum salts, or actually contain those nutrients.
Andrew
So epsum salts contain magnesium and sulfate, and gypsum contains calcium and sulfate. I guess some amendments may not have any nutrients whatsoever. They might be just carbon, or they could be some mineral amendment, like a sand or something like that. But in general, if the amendment has nutrients in it, then it could be considered a fertilizer. And I think all fertilizers in some form an amendment to the soil because you're trying to correct something, right? Does that make sense?
Mikeala
No, that's perfect. What are the different kinds of fertilizers?
Andrew
In my opinion, again, fertilizers, anything that supplies any of the essential nutrients to the crops that you're growing. And so there's all different kinds of fertilizers out there. There's fertilizers that just contain one particular nutrient or two nutrients, like a salt, like magnesium sulfate or calcium sulfate. You've got fertilizers that contain all of the essential nutrients. Oftentimes, those are pre-made synthetic fertilizers in bags that you either apply as some slow-release material or a soluble material that dissolves in water. They can have all of the nutrients, all the 14 mineralized nutrients, along with those other three that aren't mineralized, hydrogen, carbon, and oxygen. The one thing that you might be asking is the different types of nitrogen fertilizer that that's out there. I think that's a really important concept to consider. Because when you ask for what different types of fertilizer, the first thing I think of is what type of nitrogen is being applied, whether it's a nitrate-based nitrogen, an ammonium-based nitrogen, together, both a nitrate and ammonium, or if the nitrogen is coming from an organic source, which could be organic material which hasn't been broken down and mineralized. It could be something Something like urea, which is an organic form, an organic molecule that has nitrogen in it.
Andrew
All of these different types of nitrogen fertilizers do different things in the soil. Of course, you've got organic fertilizers, fertilizers made from organic material. Some of it's readily available. The nutrients are readily available because the organic materials already started to break down and mineralize. Then you've got some material that hasn't broken down yet, but could be in a the organic material would slowly release those nutrients to the plants and to the soil. Did I answer that question? Yeah.
Mikeala
I would say that people probably have questions about, is organic better I mean, does it matter to the plant whether it's organic or synthetic? I mean, that's a question we get a lot.
Andrew
Yeah, I'm sure you do. In my Master Garner plant nutrition class, when you get down to the plant level and the plant is taking up The plant doesn't care whether the nutrient, the nitrogen, the phosphorus, the potassium, calcium, iron, manganese, whatever comes from an organic source or a mineralized source or synthetic source for that matter, because it's all the same nutrient that the plant is taking up. That doesn't say that organics aren't important or good for soil. They are. It's just that the plant really doesn't care where that nutrient comes from, an organic source or a mineral source. That being said, as I had mentioned, organic sources sources of nutrients are important because typically organic sources of nutrients have carbon in it. And carbon is important for soil health. Organic sources also is more like a slow release of nutrients. It takes time for those organically bound nutrients to be broken down, turned into a mineral salt or something that can be dissolved in water that a plant can take up. So that's that process of mineralization. One of the things that when we're starting to look at different types of fertilizer out there, and because there are so many different types of fertilizer and so many contents of what those fertilizers have in them, it's important before you start thinking about applying a fertilizer, is that you want to know what the soil needs.
Andrew
And how do we know what the soil needs? You got to have a soils test because you don't want to blindly put on fertilizers if the soil doesn't need them. Certainly, the commercial industries, commercial horticultural industries and the Ag industries, especially those working in soils, they all have to take soils tests at least once every three years so that fertilizers or amendments that they're applying aren't applying something that might be too much. So for instance, lime. Lime might be actually an excellent amendment to talk about in regards to soils tests, because you You don't want to apply lime unless you know what the pH of your soil is, and you won't know the pH of your soil unless you get it analyzed because you certainly don't want to apply lime if you don't know what that pH is to begin with. Lime is contained calcium. It may contain magnesium, depending on what lime you have. So not only soils analysis would give you how much lime to put on, but it would tell you what lime to put on because there are several different kinds of lime out there.
Emily
As we always say, unless your ground is frozen or sopping wet, it's always a good time to get a soil test done. And we stand by that because that will definitely help you figure out if your soil needs to be amended and what sorts of amendments it needs. You can check your local extension service for local soil testing labs. You touched about lime already, but general overview on any tips or suggestions you have, specifically when it comes to pH amendments.
Andrew
I think that pH amendments, and typically the ones that are most used are, of course, lime. I had mentioned earlier the different types of lime. There's different consistencies, meaning some are very pulverized, which act quickly. Some are... There's stuff like hydrated lime or all different kinds of lime. There's dolamitic lime, calcidic lime. Dolimitic lime is both magnesium and calcium in it. Calcidic lime just has calcium in it. In You need to know what your magnesium and calcium ratios are in the soil before you decide which type of lime to use. That's for raising PH. You want to make sure that you're adding the correct amount of lime to your soil. That alone is important to understand what capacity your soil has to change that PH. Some soils change their pH really quickly, so you might only need a little bit of lime. And other soils take a lot of time or they're what we call well-buffered before their pH can be changed. That would take a lot of lime to do so. So all of that information is given in a soil analysis. And certainly the soil laboratory that you're sending your soil sample to will tell you what the buffering capacity is and the recommendations are based on the buffering capacity or how easy or difficult it is to change the pH back and forth.
Rachel
So Andrew, we've talked a lot about raising our pH with using lime and the different types of lime. But what if we have a high pH? What do we do if our pH is too high?
Andrew
Well, there's products that you can use also. The most inexpensive product is AgSulfur, which is elemental solver. It's typically used to lower your pH. And of course, the same with lime, your soil will have a certain buffering capacity that will change according to the characteristics of the mineral and organic characteristics that that soil will have. So you may need a little bit of sulfur if your soil is not well buffered, as in like a sandy soil or a lot of sulfur. If you have a high organic content or if you've got a lot of calcium in the soil, serpentine soils and things like that. The amount of that sulfur that you're using is highly dependent upon on that buffering capacity. And again, that's something that the laboratory analysis would tell you. There's a lot of different things that you could use. Sulfur is the one thing that is probably the slowest in reaction because it's a biological process. You could really only expect any results from a sulfur application in warmer temperatures when the soil temperature is above 50 or 55 Fahrenheit, when microorganisms start working, it's a biological process. The microorganisms will take the sulfur with water and they basically change it to sulfuric acid.
Andrew
It's biological, so you can't really do it in the wintertime and expect anything to happen. Then you've got products like iron sulfate. And iron sulfate is used in the turf care industry a lot of times to put iron on the turf to make it green up. You don't necessarily have to use nitrogen all the time. You can use iron. That's well used in the turf industry. And that is an acidic process. It occurs to certain types of fertilizers. Actually, should I say, ammonium-based fertilizers acidify the soil. And nitrate-based fertilizers actually increase the PH of the soil. So when you're fertilizing your azaleas or your strawberries, you're using an ammonium-based fertilizer. So your acid fertilizers are typically made up of ammonium and urea. They both acidify the soil. And you just look at your fertilizer bags to see what you have as far as the nitrogen types. It's interesting. You can almost determine what PH activity that fertilizer might have based on the ratio of the ammonium nitrate or the urea nitrate. Higher urea content fertilizers will tend to acidify a soil, and higher nitrate fertilizers will tend to increase the PH of the soil. So, yeah, there's other things that you can use.
Andrew
I've heard some people like using aluminum sulfate to acidify their soil, and that's wonderful if you're changing your hydrange and macrophile as blue. But I wouldn't use aluminum sulfate on anything other than just acidifying the soil and around hydranges. That's something that aluminum sulfate is very quick acting. But primarily, I wouldn't suggest to use aluminum sulfate because aluminum can be toxic. So you have to be very careful with it, and I would only use it in the case of trying to acidify the soil around a hydrange of macros.
Rachel
So Andrew, we live in the Chesapeake Bay Water shed, and we're all trying to be as environmentally conscious as possible. How should homeowners be fertilizing their lawns?
Andrew
Well, I think it's important also for homeowners to understand that the laws surrounding urban fertilization, or should I say, turf fertilization, is regulated. And so it's not only regulated for the commercial turf industry and landscapers, but we also have to follow those rules, specifically around the use of nitrogen and phosphorus. So there are some turf laws regarding nitrogen. First of all, the University of Maryland has recommendations for fertility of turf, and even homeowners can get a hold of it. If you look up University of Maryland extension, TT115. That is the legal, or should I say, the recommendation surrounding turf fertilization, that is maintenance turf fertilization. Tt115 explains that depending on what type of turf you have, the species of grass that you're working with, there are annual recommendations for nitrogen application and the amounts. Typically, when we apply nitrogen, we want to apply nitrogen as split applications throughout the year. We don't want to apply all our nitrogen at once. That's senseless. There are the recommendations that we have are that you apply the annual amount based on the type of turf you have. So you do not apply more than 0. 7 pounds of soluble nitrogen per 1,000 square foot in any one application.
Andrew
If a fertilizer contains 20% or more slow-release nitrogen, do not apply more than 0. 9 pounds of total nitrogen per 1,000 square foot in any one application. So you're allowed a little more than 0. 7 pounds if you've got a more than 20% slow release form, like an organic form, something that's not readily fertilized. You can go up to 0. 9 pounds if it's more than 20% or more of slow release nitrogen. That regulates what you can apply at any particular fertilization date. There are dates where you can and you cannot apply that nitrogen. March first and November 15th are those deadlines for application. Do not apply nitrogen before March first. November 15th is the deadline for applying nitrogen. And of course, when it comes to phosphorus, if you're intending to apply phosphorus on a turf, you have to have a soils test. Just like farmers do, got to have a soils test to determine if you can even apply phosphorus. And depending on the amount of phosphorus you already have on that soil, if you've got plenty of it's optimum, it's recommended that you don't apply any phosphorus. And so you're relegated to only applying a a nitrogen-based fertilizer and no phosphorus whatsoever.
Andrew
So a lot of the fertilizers that are balanced or have all three... Like NPK in them, you can't use. So again, your phosphorus fertility is going to be based on your soils test, and your nitrogen fertility is going to be based on the recommendations given by the University of Maryland for Maryland Turf.
Emily
So Andrew, you just used There's three fancy letters there, NPK. What does that stand for?
Andrew
Nitrogen, phosphorus, and potassium. When you look at a bag of fertilizer, what's on that bag of fertilizer, typically you'll get three numbers. The three numbers indicate the amount of nitrogen that fertilizer has by % weight, the amount of phosphate that fertilizer has by % weight, and the amount of potash that that fertilizer has by % weight. So NPK is nitrogen, phosphate, and potash. And those formulas, phosphate is P2O5, or should I say, two parts phosphorus, five parts oxygen, which is the natural form of phosphorus. And in the United States, fertilizer bags use those numbers, the nitrogen, straight nitrogen, phosphate, P₂O₀₀₀, and potash, potassium, oxide, or K₂O. So two parts potassium and one part oxygen. And then the amount The amount of phosphorus in a phosphate is around 44%, and the amount of potassium in a potash is about 83%. Do the math, figure out how much phosphorus you're applying. It's pretty easy.
Mikeala
You said do the math, and it's pretty easy in the same sentence. It's a misleading.
Andrew
A little bit. It's just doing a percent-wise of what you're applying. But yeah, that's a good one, actually. You probably could have a whole podcast in fertilizer math.
Emily
I don't think it's on our website, but there's some extension website that has a fertilizer calculator.
Rachel
I literally just had it. It was the University of California.
Emily
So with the exception of like, nitrogen and phosphorus, is there potential damage that could be done to our landscape for over applying some of these other amendments?
Andrew
Well, as I had mentioned before, the soils test tells you what you need to apply, and you don't want to apply anything more than what the soil already has or what the plants need. And this goes beyond just nitrogen and phosphorus, environmentally speaking. For the plants, if you're applying any more of a certain nutrient than what's already in the soil and what the plants need, you can cause interactions with nutrients that actually could make other nutrients unavailable to plants. There's a lot of chemistry going on in the soil. And let's say, for instance, if you have... Let's go back to the question about applying lime. All right. And if your PH is such that you have to apply lime, that you need to increase your PH, you need to look at how much calcium and magnesium is in the soil, because if you have too much calcium in the soil, it may be causing problems with magnesium uptake. There's interactions in the soil, chemical interactions that could prevent the uptake of magnesium if you've got way too much calcium. In those instances where you have too much of one thing, you certainly don't want to buy a fertilizer or any amendment that may have more of that one killer nutrient that you have too much of, too much iron, too much manganese, too much copper, too much.
Andrew
Those micronutrients there are toxic. If you've got too much calcium or too much magnesium, it could interfere with some of your macronutrient uptake. So your soils test is really important in determining which nutrients you put on, not necessarily because they might... Nutrients might become toxic directly, but they could become toxic in the sense where they could be preventing the uptake of other nutrients because there's really, in a way, a certain balance of nutrients in the soils that's useful to plants. Any increase or any amount of nutrient that might be too much in the soil, like I said, could cause interactions that prevent other nutrients from being taken up. So you never want to just willy-nilly apply a fertilizer or an amendment to a soil without really knowing what you're applying, how much you're applying, and what you really need to apply based on that soils test. That brings up an interesting question about organic materials that we're applying. Organic materials are made up of a lot of different things. And if your organic material is a compost, a compost made from material from from mushroom production, or the compost that's made from municipal food waste.
Andrew
All of those have a very different nutrient concentrations. Oftentimes, all of those have a very high salt concentration, not necessarily sodium chloride, although municipal waste does have a lot of sodium chloride because it comes from food. But these composts can have a high mineral content, and these minerals are soluble-ized nutrients, mineralized. In that sense, they are in a form of salts, which can be rather detrimental to plants if you are just applying them very concentrated-wise or not mixing them well into the soil. There's all different kinds of nutrient concentrations. If you're getting an organic compost, it might be a good idea for you to do an analysis of that. Before you or while you're getting a soil analysis, too. Keep in mind that an organic material analysis is not the same as a soils test. When you are getting an organic material analyzed, you need to tell the laboratory that it is a compost so that they treat it differently. It's a very different extraction method for either soils or compost. Okay, so you got to be careful with that.
Mikeala
I am also appreciative that you covered compost a little bit because I think people feel like because it resembles soil, that it's safe to apply willy-nilly, or you might be able to just plant in it directly. I appreciate you clarifying. It might be worthwhile to test it because not all composts are created equally.
Andrew
They're not. Also, I think when we're talking about organic material, it's important to understand that compost is very different from just a regular organic material. That if you're applying certain organic materials on your soils, especially in your garden soils or in your landscaping, that that material should be composted. It should be broken down so that that material can be readily utilized for plant growth. A lot of of our composts have a lot of cellulose in them, carbon, essentially. For instance, leaves. We're grinding up leaves and mix those into the soil, that might create a deficiency in nitrogen because your leaves themselves, after they dry up, contain very little nitrogen, but they're full of cellulose. When you get carbon-like cellulose in a soil, microorganisms are going to want to eat that cellulose up. And there's many microorganisms in the soil that can do that, that can consume cellulose, break it down into the constituent nutrients and carbon that these microorganisms need. But while they're doing that, they also need to have nitrogen. And if you have a preponderance of just carbon, cellulose in the soil, for instance, if you're just grinding up leaves and mixing them into your garden soil, you could have nitrogen deficit problems because the microorganisms are very good at taking up whatever nitrogen is there and not leaving any for the plants.
Andrew
In order to get around that, you need to make sure that your organic material is well composted before you utilize it as an amendment because you could run into situations or problems with nitrogen drawdown is what we call it.
Mikeala
That's good to know because I know there's been strong messaging on leaving the leaves, and we're often encouraging people to leave leaf litter in their garden. But what you're saying is maybe it would be more valuable to have it composted or broken down a little bit further before adding it.
Andrew
Certainly before mixing it in. If it's just a duff layer that you're putting on the top of your garden to reduce seeds or maybe as a mulch. I don't see a big problem with that. Maybe you might need a little extra nitrogen in the soil because eventually that leaf material does break down. But if you're incorporating it specifically into the soil, you really need to have extra nitrogen to help the microorganisms break that material down so that it doesn't cause nitrogen drawdown for the plants that you're trying to grow.
Mikeala
Thank you for clarifying. You learn something new even in this job every day.
Andrew
Every day. Absolutely. Every day.
Emily
So along those lines, Andrew, we always get people that talk about, will pine needles change the pH in their soil if they've used them as compost or leave them on or mix them in? What are your thoughts?
Andrew
So pine needles have those organic acids in them, but these organic acids are weak acids. And so it really comes down to the buffering capacity of the soil that you're applying these materials on. I think that there's the capacity for these types of mulches, acid-based mulches, which are pine needles or pine bark, to acidify the soil. But if you've got a well-buffered soil, these types of mulches don't really affect soil pH that much. So for instance, naturally, a lot of our soils in Maryland have a relatively acidic nature to them. Applying pine needles or pine bark on the top of it isn't really going to change an acidic soil. It's not going to drop it from 5. 9 down to 3. 2 or anything like that. Can't rely upon those particular mulches to acidify your soils if you're growing strawberries or anything like that. It's good to use them as backup, but it really comes down to the buffer capacity of the soils and the soil's ability to resist change in pH. If it's an unbuffered soil, those types of mulches may have a small effect. If it's a well-buffered soil, which doesn't want to change pH, then they probably will have little to no effect on soil pH.
Andrew
Soil's test, soil's test, soil's test.
Mikeala
Thank you.
Andrew
Yes, you're welcome.
Emily
Okay, so I'm going to put us in a box now. And by that, I mean, we've talked a lot about soil, but what about for those of our listeners who have raised beds? Should they treat those different than treating their actual ground soil? Or is it okay to treat them the same? Obviously, we'd recommend you take soil tests in your raised beds as well, but how should this be applied for raised beds?
Andrew
Raised beds can be made up a lot of different stuff depending on what your organic content is, depending on if you decided to make a raised bed because your clay soil was just too difficult to work in, or let's say an urban environment where your soil is Soils are toxic because they have a lot of lead and other heavy metals in them. Urbanite, which is urban soils, which could be a lot of trash, refuse, bricks, cement, things like that, that be very unappealing to plant roots. We make these raised beds, and those beds could have anything. They could have a soil content, they could have organic content, they could have both, depending on the ratios that were originally put in. My beds at home were raised because I decided that I didn't want to grow in the type of soil that I have around my house. So I just purchased bags of what we call topsoil per se and compost. I usually get a manure composted cow manure, and I just add those in. Typically, when I go redo the soils every year, I just half and half it to just bring up the level of the soil in my raised beds.
Andrew
The soils test basically tell me any other amendment that I might need to prevent any deficiencies or toxicities or interactions with the nutrients. If you've done a soil analysis and your organic matter comes out to be 50%, then you probably should have done an organic test. Keep that in mind that if you have primarily an organic soil, or should I say an organic media, you want to get a compost or organic analysis to it.
Emily
That's good to know
Rachel
- Andrew, we've talked about all the things that we should be adding and how to add them. But what are the things that we shouldn't add?
Andrew
Well, that could be as wide-ranging as don't add what you don't know, what it's in there. So don't add anything that you don't know what you're adding, like compost. If your soil has certain nutrients in it, as I said before, your soils test will tell you, and an organic compost test will tell you what you're adding. So you need to make sure that you're not adding anything more than what's already in the soil, especially any particular nutrient. So you got to be careful with that. I had mentioned already that you want to stay away from organic material that has a lot of cellular Cellulose, leaves, sticks, things like that, because that could create nitrogen drawdown in the soil if you're incorporating. Don't incorporate mulch into the soil because it's not a really good form of organic material. It is in a sense, but you got to add that nitrogen to break down that cellulose. You got to be careful about what you're applying there. Again, apart from applying amendments that already have a particular nutrient that might already be in the soil or too much of I would never utilize aluminum sulfate. That was one that I said I would never use that as a soil amendment unless I'm doing specifically making my hydrange as blue.
Andrew
But other than that, organic material is a fantastic amendment, especially if it's broken down in the compost, because that really starts, that kick starts this whole soil health thing. You bring in organic material, you're going to bring in microorganisms, you're going to bring in smaller organisms that churn through the soil, the fungus and the microorganisms. They create the mucilages that bind soil particles together and creates the structure, the pathways for air and water to percolate down through the soil. So all of these things, organic material is fantastic. You just have to be wise in using it.
Rachel
That makes perfect sense. Don't add things if we don't know what they are, and we need a soil test ahead of time to even know what we have in our soil. Yeah.
Mikeala
And along Those are the same lines of this question, I know a lot of people, especially around here on the Eastern shore, have these soils. They want to incorporate sand into their soils. Is that something they should avoid adding?
Andrew
Yeah, it makes concrete. Yeah. Okay. Right. Sand, if you put sand together with clay or a silt, a silty or a clay soil, you only make concrete. And take it from me, I've done it. Yes, I did that before. Then there are some people that out there, they think that gypsum breaks up clay, and it doesn't. Gipsum is good for sodic soils, which are mucky soils, the soils that have a lot of sodium in it. And gypsum is good for flushing that sodium out, and it changes a mucky soil. And so clay soils can benefit if they are full of sodium. Or any soil that's full of sodium, you can use gypsum to flush that sodium out. But sand is no good. The best thing for the types of soils that are high in silt and high in clay, organics. The organic material is what actually, like I said before, brings in the microorganisms that create the structure in the soil. And of course, the nutrients that's in the compost create an environment that will be more inviting to small burrowing animals and things, anything that will create air spaces and pockets and bind soil particles together is good, and organic is chief for that.
Andrew
So the best thing to amend heavy clay or silty soils is with organics.
Mikeala
Good.
Emily
Well, I think that's it. So thanks so much for coming back on the podcast, Andrew. You were always such a wealth of knowledge.
Andrew
Well, it's so cool hanging out, you three. I love it.
Emily
We appreciate you taking the time to come on.
Andrew
It's fun to talk to you three. It's fun to help your program out, especially this one, your Master Gardener programs. I absolutely love helping you three out. You're the best.
Rachel
Well, that's all we have for this episode listener. We hope you enjoy it and we'll tune in next month for more gardening tips. If you have any garden related questions, please email us at umegardenpodcast@gmail.com or look us up on facebook at gardentimepodcast. That's garden thyme. For more information about the University of Maryland extension and these topics, please check out the University of Maryland Extension Home and Garden Information center website at go umd.edu backslash. Thanks for listening and have fun getting down and dirty in your garden. Goodbye
Mikeala
The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Its hosts are Mikaela Boley, Princpalr Agent Associate (Talbot County) for Horticulture; Rachel Rhodes, Agent Associate for Horticulture (Queen Anne's County); and Emily Zobel, senior Agent Associate for Agriculture (Dorchester County).
Emily
University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class.
:up beat music: