Farm & Garden
Learn and Improve Your Soil Type
Let’s learn about soil types and how to improve yours. Healthy soil acts as the structure from which we grow fruits, flowers, and vegetables.
Healthy soils ensure healthy farms and gardens, and this makes or breaks livelihoods. Without considering the land’s needs, the yield and quality of your harvest diminish. Like any living organism in one’s care, you must observe and nurture its health. Today we learn what soil is, what types of soil exist, and how to improve your soil to produce lush, healthy plants.
What is soil?
When farmers or gardeners talk about soil, they refer to the top organic layer of the Earth’s land surface and its topsoil beneath. Land surfaces are not soil in waters deeper than 2.5 meters and cannot sustain rooted plants.
Soil is also that part of the upper surface acted upon by living and non-living factors — such as climate or microorganisms. The USDA references “Soil Taxonomy: Second Edition,” which states the lower boundary of soil is 200 cm, or six and a half feet, for classification. Often perceived as the “Earth’s skin,” this superficial layer consists of minerals, organisms, air, and water.
Visit Soil4Kids to discover all seven general roles which soil plays.
As a central part of cultivating food and flowers, soil is by definition organic. This means it consists of carbon-based organisms, byproducts, and materials. The land has a state of health because it is alive. Plants live in these top layers, and they need the air, water, nutrition, and structure the soil gives.
The earth is in a constant state of flux dependent on environmental conditions. Rains provide water, and both tiny critters and plants’ roots aerate the soil as they carry on. Decomposing creatures and plants nourish living ones.
We connect with the soil on almost a spiritual level, as well. We are that which we eat, which at some point likely derived from the land. Countless creatures cohabitate while natural forces act upon them.
This happens on both grand and micro scales in a self-nourishing interplay. We are part of the Earth from which we arise — ashes to ashes, dust to dust. Putting our hands and feet into the soil reminds us of the humility in knowing our interconnectedness.
Types of soil
So what kinds are there? Soil comes in many varieties and colors, and knowing your soil helps to enrich your gardening practices. Plants produce their food from the sun’s light energy. But they need vitamins and minerals like nitrogen, phosphorus, and potassium to supplement.
We define six main types of soil, which each have unique characteristics: chalky, clay, loamy, peaty, sandy, and silty. Your soil type determines how well your garden drains, its acidity, nutrition, and more! Of course, different plants like different kinds of soil, as well. Next, we will look at examples to identify and learn your farm or garden’s needs.
Pinpoint chalky soil by its larger, rocky pieces and its tendency to drain well, like sand. Like some places in East Tennessee, you find this soil type over limestone bedrock and chalk deposits. These minerals cause the soil to be alkaline, and you can lower the pH by adding composted materials and sulfur, for example.
Pros: Chalky soil drains water freely.
Cons: It’s alkaline and can stunt growth or yellow leaves. Balance pH and workability with organic humus.
Vegetables: Lilac, Weigela, Madonna lily, Pinks, Mock Orange
Ornamental: Spinach, Beets, Sweet Corn, Cabbage
Clay soil is very sticky, clumps together when wet, and often takes a red/orange hue. Clay contains great nutrition, but its tendency to clump together and keep water inhibits root growth.
Clay warms more slower than other types, and you find it where water once flowed — like some parts of West Tennessee. When it dries, clay soil cracks and breaks apart. Mix in composted organic matter and sand to help improve drainage of this soil type.
Pros: Clay soil hold water and nutrition.
Cons: It compacts, drains poorly, and can choke plant roots. When dry it cracks.
Vegetables: Shrubs, Fruiting, & Ornamental Trees
Ornamental: Helen’s Flower, Aster, Bergamot, and Flowering quince.
An ideal for many gardeners, loamy soil mixes sand, silt, and clay in a way that requires some maintenance and upkeep. Loam drains well and provides excellent structure, and it contains multitudes of organisms.
These ecosystems nourish without the need for conventional fertilizers if desired. Fortunately, loamy soil tends to be blacker and acidic and dries more slow during the summer heat. One must amend soils each year by composting, mulching, rotating crops to improve soil quality.
Pros: Loamy soil has a strong structure, holds moisture, drains well, and maintains nutrition.
Cons: Requires monitoring and maintenance.
Vegetables: Most crops.
Ornamental: Climbing vines, bamboo, perennials, tubers, and shrubs. (i.e. wheat, tomatoes, sugar cane, peppers, corn, cotton, green beans, etc.)
Identify peaty soil by its spongey, damp texture, and it appears more brownish than other kinds. Peat retains water well but lacks the nutrition of organic compost. A very acidic soil, you can raise pH by including organic compost or lime. Peat soils will warm quickly but slower than sand.
You find most peats in bog areas like the Carolinas or where folks import it for garden amendments. Yet, peat moss’ harvest is unsustainable given its slow-growing nature. Also, peat acts as a carbon sink when undisturbed. Thus, I urge you to consider alternatives like coco coir or some old-fashioned compost.
Pros: Heats up quickly, and retains water well.
Cons: Unsustainable practice. Drains poorly. Acidic.
Vegetables: Brassica, Legume, root and salad crops.
Ornamental: Heather, Lantern Trees, Witch-hazel, Camellia, & Rhododendron
Sand feels gritty and drains well, but it lacks the nutrition that plants desire. Sand warms fast, but nutrients tend to wash away. Sand by itself tends to be more pH neutral because it’s non-reactive lacks retention.
It appears more yellowy depending on the kind of sand. Add organic compost and mulch to build soil structure, pH, and nutrients. You tend to see sandier soils in coastal areas and deserts.
Pros: Sandy soil drains and dries fast. Warms quickly.
Cons: Needs amendment for nutrition and water retention.
Vegetables: Lettuce, strawberry, nightshade, corn, gourds, carrots, and parsnips.
Ornamental: Tulips, Hibiscus, Sun roses, and Tree mallow.
Formed by sediment deposits from active watersheds like rivers, silty soil often appears greyish in hue with a soapy texture. It shares some characteristics with clay soils.
These characteristics include water retention, higher nutrients, and a tendency to clump together. Mix in composted organic materials as well as sand to improve upon drainage. Silty soil also warms more slower like clay.
Pros: Silty soil holds moisture and contains a high nutrient density.
Cons: Amend with organic humus to improve drainage, structure, and nutrition.
Vegetables: Most crops provided adequate drainage.
Ornamental: Mahonia, New Zealand Flax, shrubs, climbing vines, Willow, Birch, Dogwood, and Cypress trees.
Visit eartheasy to learn about soil testing, what plants prefer which soil type, and more.
As you can see, not all soil is the same. Before now, I had failed to realize how many kinds of soil there could be. You might think there is one kind, dirt. But your soil can differ depending on where you live — whether on a plain, by the coast, or even in mountainous terrain.
How awesome is it to think about all the different creatures living and working together! With myriad species of plants, they all have niche preferences on what soil they like. Now you can identify your soil type, and you know how to amend it to provide a nurturing environment for your fruits, flowers, and vegetables.