Garden Primer – Do a Mason Jar Soil Test

Every year in the spring I do a mason jar soil test to see the soil structure in my garden. It helps me decide if I need to make any amendments to the soil. This is a simple and easy test to take if you are creating a new garden area, you’ve recently moved, or you want to do a cool experiment with your kids.

Knowing the structure of your soil will help you determine how much water and fertilizer your plants will need, and what soil amendments to make. Your soil is a mass of mineral particles, water, air, and dead organic matter. The size and form of those particles make up the basic soil structure.

An understanding of your soil is perhaps the most important aspect of gardening and will give you the best success.

There are three soil components – Clay, Sand, and Silt

Clay is the smallest mineral component. These tiny flat particles fit closely together to create the greatest surface area of all soil types. Clay soil contains needed nutrients and also stores water well. So well in fact, that drainage is slow in clay soil. It is also the slowest to warm in the spring.

Sand makes up the largest particles in soil structure. These are rounded, rather than flat and allows for larger space between the particles. Water drains quickly from the soil that has a lot of sand and the nutrients drain faster too. If your soil is mostly sand the plants will need more water and fertilizer.

Silt represents the middle size pieces. It is made up of rock and mineral particles that are larger than clay but smaller than sand. Individual silt particles are so small that they are difficult to see. To be classified as silt, a particle must be less than .005 centimeters (.002 inches) across.

The combination of these three particles is called loam and is considered the ideal garden soil. Knowing how close (or far) you are from loam will help you decide what amendments to make this spring planting season.

The Mason Jar Soil Test

Use a clear, clean, empty jar with a tight lid. A pint or quart Mason jar works fabulously. Fill the jar about half full of garden soil. You can use soil from different areas of the garden to get an overall view or make a test for each garden bed. Fill the jar nearly to the top with water. Leave room for shaking. Tighten the lid and shake the jar for several minutes so that all the particles are in suspension. Set your mason jar soil test aside for several hours, so the particles have a chance to settle. They will separate into clay, silt, and sand layers.

Read the Results of your Mason Jar Soil Test

The bottom layer will be the heavier particles, sand, and rocks.

The next layer will be the silt particles.

Above that there’re the clay particles.

Organic matter may be floating on the surface of the water.

The color of the soil gives a clue to its character – light colors usually have less organic content than dark soil and dark soil warms faster in the spring.

To calculate the type of soil texture in your garden, use the this graphic by the USDA’s Natural Resources Conservation Service (image below). Just check out where the lines cross on the Soil Texture Triangle map to learn what type of soil you have in your garden.

For instance, if your jar test is 20% clay, 40% Silt, 40% sand = Loam, you have the perfect combination. You’ve been working hard in your garden!

Do your calculations:

30% clay, 60% silt, 10% sand = Silty Clay Loam

15% clay, 20% silt, 65% sand = Sandy Loam

15% clay, 65% silt, 20% sand = Silty Loam.

You can also use the NRSC’s Soil Texture calculator on their official website or download the interactive Excel version of the Soil Texture Triangle (you’ll need to have macros enabled to use the document).

Plants and Soil Type

Soil type influences the amount of water and air that can reach plants’ root systems. If the soil is too dense like wet clay, the roots will suffer from oxygen depletion. Clay soil also drains slower than other two types of soil, which means that the soil remains soggy, which can lead to root rot.

On the other hand, clay soil is rich in certain nutrients some need to thrive. That’s why, you need to achieve a great balance between the three soil textures.

By contrast, sandy soils drain too quickly which may leave plants without the much needed water. They also lack the nutrients clay soil have and because of these they are usually infertile. But a sandy soil is much easier to work with than clay soil and because it is so loose it is preferred by some plants, onion and carrots included, because it allows them to easily expand their root system. A loose soil is loved by potatoes too for the same reason.

Plant growth is affected by the texture of the soil not just by nutrients, sun exposure, and watering. Soil texture influence three features of soil every gardener should take into account when starting a vegetable garden:

Permeability;

Water-holding ability

Workability.

Soil permeability shows how fast air and water can reach a plant’s root system. Roots need not only water to survive, they need air too.

Water-holding ability refers to the level of drainage a type of soil has, while workability means how easy a type of soil is to work with as a gardener when doing maintenance work such as tilting.

You can fix most of the issues tied to a too dense soil or a too permeable soil, and so on with various amendments. The most critical one is adding organic matter, which can offset the disadvantages of having too much of a type of inorganic matter (clay, silt, or sand). Organic matter along with sand, clay, and silt merge to create clusters known as aggregates. The way aggregates are present in soil gives soil structure.

Why Soil Structure Is So Important

Soil structure is primarily important for plant growth. A poor soil structure will impact negatively, the amount of water and air a plant has access to, nutrient availability in soil, and microbial life activity (microbes in soil help break down organic matter and improve soil structure or at least prevent it from getting worse.)

Depending on soil structure, soil can be easily destroyed. Excessive tilting when the soil is too dry or too wet can lead to damage to its structure. Also, driving heavy machinery over wet soil can compact it and prevent it from properly driving water, air, and nutrients to plants’ roots.

You can see examples of soil structure damage on forest roads or unpaved countryside roads after heavy rainfall. If heavy equipment has compressed the soil, you’ll notice large pools of water on the road as the soil particles are too tight to allow proper drainage.

These other types of soil will require some amending with organic materials.

Common amendments include:

• Yard trimmings compost – Sometimes sold as “garden compost,” yard trimmings compost is the most widely available material suitable for high-rate incorporation into soil. Private composting companies usually produce it.

• Leaves from deciduous trees – Leaves are perhaps the best and most readily available organic matter source for vegetable gardens or other areas that get some annual tillage. Ask your friends to save their leaf bags for you. Don’t let them go to waste in a landfill!

• Crop residues – Fresh or composted crop residues may be available from nearby farms, tree-trimming companies, or even your own kitchen. Uncomposted crop residues may contain weed seeds, while properly composted residues are weed-free. Make your own kitchen compost bin.

• Animal manures and manure composts – Many manures and manure composts have high soluble nitrogen, ammonia, or salt content, or high pH (above 8)In general, it is best to avoid manure and manure composts for high-rate applications to planting beds. Use manures in small amounts to replace nitrogen–phosphorus–potassium fertilizers.

When to Amend the Soil

You should amend a poor soil structure before you grow anything in the soil, especially if we’re talking about veggies and annual flowers. It is best to use amendments that are gentle and break down slowly. Like we said adding organic matter to the soil is the best way to go. Microbial life in the soil will break down the organic nutrients into humus, which is a boon for your plants.

Compost, shredded bark, and peat moss break down slowly, the last two taking years to completely turn into humus. Compost doesn’t need that much time to break down (several months is enough), but it is rich in nutrients your soil and plants desperately need.

Also, a boost in nutrients means that the microorganisms in soil will be able to better aerate the soil, increase the amount of hummus in soil, and protect root systems from fungi and diseases.

If the soil is left unamended, it might be too dry or dense for new plants’ roots to grow. If plants do manage to grow in such soils, they might get stunted or just die in the process. If you need to plant crops, amend the soil before you plant anything in it. Manure takes just a few weeks to break down, which makes it a great amendment n the short run.

In milder climates with rainy winters, you can amend the soil every year after fall cleanup. In climates with rainy springs and winters, amend the soil in spring before planting the crops.

How to Amend the Soil

For annuals and vegetables, organic matter needs to be spread evenly on the soil and worked into the soil down to 9 inches. You can do this job manually or use a rototiller. Loamy soils need a 2 to 3 inch layer of organic matter. If the soil is sandy or mostly clay, add 4 to 5 inches of organic matter to it and work it in at a depth of 9 inches.

If you stick by the 9 inch rule, you’ll have a top layer that is 50% amendment and 50% original soil (clay or sand). Just like loamy soil, soils that are amended regularly need just a layer of 2-3 inches of amendment. When it comes to annuals and vegetables, amend the soil BEFORE you plant any crop.

For shrubs, trees, and perennials, you don’t have to stick to the 9 inch rule as you might damage their root systems in the process. Just spread the organic matter over soil and let rain, earthworms, and beneficial bugs get the nutrients within the soil.

If the shrub, tree or perennial doesn’t have a shallow root system, you could help earthworms, water, and beneficial bugs, by working the amendments into soil but not lower than one inch.

What Gardening Problems Are Caused by Poor Soil Quality?

Many problems with home vegetable gardens, fruit trees, shrubs, and flower gardens are caused not by pests, diseases, or a lack of nutrients, but by poor soil physical conditions.

Symptoms of poor soil quality include the following.

The soil is dried and cracked in summer.

Digging holes in the soil is difficult, whether it is wet or dry.

Rhododendrons, hydrangeas, and other shrubs wilt in hot weather, even with added water.

Leaves on shrubs turn yellow and have brown, dead sections on them, particularly on the south side of the plant.

Tomatoes and peppers get blossom-end rot, even if fertilized with calcium.

Water tends to pool on the soil surface and to drain slowly, or it runs off the surface.

Download this handy publication, Improving Garden Soils with Organic Matter to learn more ways to improve your soil and happy gardening!

Other gardening ideas found at PreparednessMama:

The Gardeners Arsenal – 10 Things to Spray, Sprinkle & Brew for Garden Pest Control

Slug It Out – Natural Slug Solutions

4 Permaculture Principles Every Gardener Should Embrace

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