Soil vs Clay

If you love gardening and want to make the most of every harvest, you are going to want to know the difference between soil and clay.

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If you love gardening and want to make the most of every harvest, you are going to want to know the difference between soil and clay.

Soil is a combination of different minerals, gases, and living & non-living materials. Soil is loose, full of nutrients, and is essential for growing plants. Clay is a very fine mineral compound found within soil in small or large quantities. The amount of clay can determine soil quality.

Once you really get into gardening, your passion for this incredibly therapeutic hobby will encourage you to get into the details of how to master your craft. At the end of the day, there are a lot of tricks to this trade that can make all the difference in the quality of each harvest, and by being familiar with more tactics, you will be able to become a better gardener. The most important thing you want to focus on is the quality of your soil by determining its contents. Regardless of what you are growing, the more you know about your soil and how much clay it has in it, the better off you will be. To understand this further, let’s take a closer look at the relationship between soil and clay.

As you begin your next gardening season, you should review the specifications that the United States Department of Agriculture has for determining the quality of soil. If you are buying soil from a nursery, try to opt for trusted brands that have a reputation within the gardening community for delivering quality yields.

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When most people first get into gardening, one of the biggest mistakes that they make is to underappreciate the value of having soil that is rich and balanced. This is due to a lack of understanding of just how complex soil structures are and how vital each component can be for delivering optimum results.

In the past century, much of society has dropped the ball on appreciating soil, as we carelessly approached our food growing with little to no consideration of how poor gardening and farming practices have led to soil infertility and land degradation.

When we actually break down soil and its components, we see that this is a living ecosystem for countless micro-organisms. Soil, much like any ecosystem, can be extremely fragile and can be sabotaged, if not cared for properly. We experienced this first hand after destroying a lot of our farmlands with unsustainable agricultural practices, which is why the United States Department of Agriculture has very strict regulations on how to treat, manage, and nurture this precious natural resource.

We have learned that by taking care of our soil, we are ensuring that growing food on our planet is something that can be continued for generations to come so that food shortages are thing of the past and that world hunger can be overcome. Now, let’s dissect soil so that we can better understand how to take care of it.

Soil Contents

When most people commonly think of soil, they have a mental image of plain old dirt in their minds. Now, while the two may have some similar appearances, dirt is essentially lifeless and is not capable of food production on its own. What dirt is in relationship to soil is that it acts as a filler between the nutrient density of materials that are found within fertile soils.

The soil itself is a complex ecosystem and like most ecosystems, it varies in its inhabitants. We often hear the term soil thrown around as a blanket statement implying that it is magic dirt that can grow food, but in reality, soil and soil content is something that changes depending on a number of different conditions. Here are the determining factors that influence the contents and quality of soil.

Foundation Materials

The biggest factors that determine what kind of soil you will have will be what the origins of the materials are. All soil is developed from a foundational material, which in turn influences the structure and contents of the resource itself.

The way this occurs is through a geological breakdown of rock materials that eventually become the foundation of the soil. Soil that originated from a stable rock surface will have a much different structure and content than soil that was created from a river’s runoff. This will influence the geological material of your soil and will add sand and clay into the mixture. More on this later.

Decaying Materials & Living Organisms

At the end of the day, the primary nutrient value found within soil comes from a living organism or decaying material, which was once alive. This is the most key aspect of soil that makes it suitable for growing food and plants.

Throughout the development of any given soil, living organisms made their way through this ecosystem and contributed to the circle of life. As these organisms live in the soil they are dropping off nutrients during their life cycle - either directly through droppings or when they die and they decay into nutrients for the soil.

In addition, plants will naturally find a way to live and thrive in soil without being planted by humans, which will provide vital nutrients to the soil when they die.

Weather Patterns

A major influence on the health and contents of soil materials is the external weather patterns that the soil sits in. It goes without saying that plants prefer some types of climates more than others.

A common sign of this is to assess how plants flourish in weather conditions that are warm, sunny, and receive rain, as opposed to cold climates that receive little moisture. In addition, rain is something that enables soil nutrients to become more apparent in a soil’s life cycle.

This is why we tend to grow certain types of foods in specific parts of the world and also choose to plant our crops during harvest cycles that are more sustainable for optimum food production. However, this can be challenged with indoor food growing operations that have complete control over their crop’s climate conditions.

Identifying Soil Contents

As we just discussed, there are so many variables that influence the health of soil and its contents. Regardless of whether you are operating a large-scale industrial farm or are simply a passionate home gardener, understanding what is in your soil will be vital for making the most out of every harvest.

Luckily, there are some easy ways that you can test the contents of your soil right at home, without needing any fancy equipment or having much previous knowledge of soil. Here is an easy way you can identify the contents of your soil.

Shake Test

The first thing you want to do is grab an old mason jar or a clear receptacle to place a sample of your soil into. Next, fill the object with some water, as well as a little bit of soap, and give it a good shake. Once shaken, you will see the contents of the soil circulating around and slowly moving down to the bottom. At this stage, you want to let the object sit without any movement for at least a full day.

When you return to your soil sample, you will see that the soil has broken itself down into layers. These are essentially the layers that your soil is in when in your garden. What you want to see is an even balance of materials within the sample, which is known as loam soil.

Loam soil is considered perfect for growing food and plants as it provides the ideal amount of nutrients and a balance of all other materials within the soil that will help your plants grow. Loam soil is made of three primary materials: silt, sand, and clay. If your soil has an imbalance in materials and your sample is still murky, even after a full day’s wait, then you likely have a larger amount of clay content in your soil than you want. More on this later.

Test Kit

Once you have done your initial shake test, it may be wise to go the extra mile and opt for using a soil test kit to further assess the nutrient value of your soil.

This can be very helpful for gardeners that are having a hard time getting their plants to grow properly - even when approaching all aspects of their garden as instructed. In addition, passionate and competitive gardeners also use soil test kits in their garden as the results help them pinpoint how to take an optimal approach.

Using a soil test kit is easy and affordable. The first thing you will want to do is test your soil’s pH level by taking a small sample of your soil and pouring it inside of the test tube that came with your test kit. Next, you will add the powdered material that came with your test kit which is marked for pH. Add water to this mix and shake. The color that the tube becomes after your shake will determine the pH level of your soil as you match it with the chart included in your kit.

You will follow a very similar process for identifying the rest of the nutrients in your soil such as Nitrogen and Potassium content. By identifying these minerals, you will be able to determine what kind of fertilizers are best suited for your soil.

Furthermore, if you are a very competitive gardener or are running a large food-growing operation, you may want to take your soil test further by taking it to a soil lab. The results you get from a professional lab test will be much more precise than what you get out of an at-home test kit.

Soil Maintenance

If you have got healthy soil in your garden, then the foundation for growing food and plants is there and you will be able to start planting. However, having healthy soil in your garden is only half the battle, as this precious resource needs to be taken care of and maintained.

There is a lot that goes into soil maintenance, which will require regular upkeep on your end throughout the year so that you can have an optimal harvest. Let’s dive into what you need to do to maintain your soil.

Crop Rotation

One of the biggest mistakes a gardener or farmer can make is to not rotate their crops. This has been a major issue in the past, as failure to rotate your crops on an annual basis can be catastrophic for soil health.

This gardening technique has been around for thousands of years and it was only during the rise of industrial farming that we abandoned this traditional practice to pursue more efficient ways of growing our food. This led to land degradation and soil infertility, as crops exhausted soil nutrients, which made the land useless for future harvests.

To avoid this from happening, all you need to do is simply rotate the area that you plant your crops in. The reason this is so effective is it prevents your plants from sucking up vital nutrients within your soil to the point of depletion.

Your plants will prefer specific nutrients within the soil that they are planted in. By rotating your crops, you are giving those nutrients a break and some time to restore themselves back to health.


As you continue to grow in your garden, you will notice that each harvest will start to produce less yield and lesser quality plants - even with crop rotation!

You can water and rotate all you want but you still need to revitalize your soil each year by adding nutrients into your garden. The best way to do this is to add manure into your soil at the end of each harvest.

Manure is an organic waste material that is full of rich nutrients for your soil to break down. You want to add manure at the end of each harvest cycle so that your soil is in prime condition by the time you start planting.

Alternatively, you can use fertilizer to perform a similar function, but manure is still much more preferable to this as it is an organic compound, which will improve all nutrients and aspects of your soil’s fertility. Fertilizer, on the other hand, is a chemical-based nutrient additive that generally only targets a specific nutrient to replenish.


When you were a kid, you likely played with ‘clay’ (playdough) and created formations and structures. While this type of children’s clay emulates the real thing, they are actually much different.

Clay is a mixture of minerals and microscopic sediments, which are found in some solidified rock formations. We most commonly know it as a gooey substance found in rivers, streams, and our soil. To understand clay better, let’s explore what it’s made of and what its relationship to soil is.

Clay Contents

When you take clay into your hands and rub your fingers through it, you will feel that it is extremely finite - almost like dust.

If you try to find a single grain of clay, it will be next to impossible, as most of the contents of clay are microscopic. On the opposite end of this spectrum would be a material like sand, which is quite different from clay in many ways. Sand, on the other hand, is something that you can easily identify and see with your bare naked eye - due its grains being much larger.

The way clay is formed is when rocks with silicate are broken down and their sediments are released. A combination of minerals like magnesium, silica, calcium, potassium, and aluminum are the building blocks that make up the primary contents of clay.

Once this mineral compound comes into content with water, we begin to see clay as we all know it - a gooey, droopy substance.

Benefits Of Clay

On its own clay is really only useful for things like ceramics, but in combination with soil, it makes this natural resource all the more powerful.

Clay is a fundamental aspect of soil and any healthy fertile garden will have a certain amount of clay in its contents. With that being said, too much clay is not good either. As we mentioned previously, when we test the contents of our soil in a mason jar, we can see the different layers of material within the soil.

Healthy soil will have a balance of materials, which will amount to a strip of clay within the jar. However, an imbalance of clay will be signified by a murkiness that takes multiple days to settle to the bottom. If you have too much clay in your soil, this can result in drowning your plants due to a lack of filtration.

With that being said, a balanced level of clay in your soil can have tremendous benefits for your garden. Here are some of the ways clay will keep your garden healthy.

  • Moisture Retention - since clay is such a finite material, it will help your garden retain moisture. The microscopic materials found within clay allow your soil to hold on to moisture better, but you should be careful not to have too much so that water can still drain out.
  • Nutrient Retention - in addition to holding water better, the contents of soil will also help your garden retain its vital nutrients.
  • Stabilization - as your plants begin to expand their roots in your garden, they will be looking for something to latch onto for stability. Clay provides a perfect material that is sturdy and allows your plants to stay fortified within your garden.

Ultimately, clay can have a lot of benefits for your garden and the health of your soil. The key thing is to identify how much clay content you have in your soil before you start planting to ensure that you don’t have too much or too little.

Identifying the content of your clay/soil relationship can be detrimental to maintaining a quality garden or can give you an extra edge as a competitive gardener, which is why we highly advise making a shake test and using a test kit to assess the nutrient value and contents of your soil and clay.

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