What are Different Types of Soil
What is Soil?
There may be as many definitions of soil as there are people with an opinion about it. The following goes beyond the purely physical to a more functional understanding of soils.
The soil is a living, dynamic resource that supports plant life. It is made up of different size mineral particles (sand, silt, and clay), organic matter, and numerous species of living organisms. The soil has biological, chemical, and physical properties that are always changing. (from National Soil Survey Center et al.)
Dirt is often called soil out of place, but dirt does not have the ability to support plants, or the intricate interplay of biology and physio-chemistry that makes soil unique.
Types of soil
Evaluate soil types by 3 basic properties
- pH level
Structure describes density
- Clay is heavy and sticky.
- Sand is light and dry.
- Loam is a balanced combination of clay, sand, and loam.
Nutrients provide food necessary for plant growth
- Nitrogen nourishes stems and foliage.
- Phosphorous sustains roots and flowers.
- Potassium promotes food production.
Soil pH Level
Correct soil pH allows the root system to absorb crucial nutrients
The pH scale runs from 0 to 14.
- A pH level of 7.0 is neutral.
- Any pH below 7.0 is acidic, the further below the more acidic.
- A pH above 7.0 is basic, or alkaline, and like acids, the farther from 7.0 the more basic.
Typically flower and vegetable gardens require a 6.0 to 7.0 pH level.
Soil testing, available through county extension services and many local gardening centers, provides the most efficient determination of soil types. Follow the sample collection instructions carefully for the most accurate results. Look for tests that report organic content (typically only 1%, needing to be at least 3%).
Establishing a proper balance between retaining moisture and draining well yields productive soil types. Roots need moisture available to sustain them during dry periods between rains or watering, yet won’t tolerate standing water. Soil needs to be porous enough to allow air to circulate through the roots, yet strong enough to support the plant’s mass for growth.
Whatever soil type adjustments are made, work into depth at least twice the depth of the addition – work two inches of the top layer in at least four inches, three inches of the top layer in at least six inches, etc.
- Use 10 pounds of lime per 100 square feet to raise soil pH level 1 point.
- Use 10 pounds of sulfur per 100 square feet of soil to lower pH level 1 point.
- Wait two weeks after adjusting soil pH before adding fertilizer.
Adding organic matter:
- Replaces depleted nutrients.
- Both break up clay type soil to reduce its stickiness and helps sandy type soil retain moisture.
- Organic matter sources:
- Rotted manure
- Leaf mold
- Peat moss
Cover crops like peas, beans or buckwheat, are grown, then cut and worked into the soil to increase organic matter.
- Buckwheat grows well in many climates and works in fairly easily.
- Harvest buckwheat when all plants show bloom production.
- Cut to ground level and work into the soil with the roots.
- Large garden areas may require tilling.
When adding organic material work at least a 1:3 ratio. Work two inches of compost material through six inches of soil.
Work in fertilizer with organic material when preparing the garden. Broccoli, cabbage, cauliflower, corn, onions, peppers, potatoes, tomatoes, and other high feeding plants require side-dressing fertilizer boosts.
Working the soil
Make soil adjustments during autumn to allow the soil to blend well before production. Leave the spaded are rough to allow winter conditions to maximize benefits.
Be sure soil is dry enough to work in the spring:
- A clenched handful should break apart rather than cling together.
- Working the soil while it is still too wet causes compression, reducing oxygen needed for microorganisms, earthworms, plant growth, etc.
- Add organic matter two weeks prior to planting. Work four inches of top layer six to 12 inches deep.
There are different soil types and different species of plants have different requirements. Soil types vary in different areas and there is no much point in trying to alter it unless you are doing it on a commercial basis, for example, a football club trying to get optimum soil type for the species of grass it is using. Once you have established the type of soil you have, there are lots of ways it can be improved. If your soil is in good condition then your plants will be too.
Characteristics of Different Soil Types
Sand, Loamy sand, Sandy Loam
These are well drained and aerated and workable for most of the year. They are very light to handle and quick to warm up in spring. Unless they have a very high organic matter content they are prone to drying out too quickly, and additional watering will be needed. This extra watering will also help to wash out the plant foods and lime from the soil, so they are likely to be acid (except for some coastal soils). They are often referred to as hungry soils and need lots of extra feeding. With careful management, however, they can be amongst the most productive soil types.
Medium loam, Sandy clay loam, Silt Loam
These are the average soil types. They achieve a good balance between the ability to be very productive and the minimum of attention. The medium loam group is probably the best in this respect.
Clay, Sandy clay, Clay loam, Silty clay loam, Silty clay, Silt
Although these soils are difficult to work and manage, they usually have good supplies of plant foods and lime. The main drawbacks are the high water-holding capacity (which means they are late to get going in spring) and the effort required to work them. You will need to catch just the right weather conditions to avoid hard work and damage to the soil structure. The use of heavy machinery (and especially rotavators) should be avoided at all costs, particularly when the soil is wet.
Peat Moss or Fen Soils
Provided they are not too acid and have effective subdrainage, these are probably the best natural soils available. They are rich in plant foods, are easily workable and early. It is possible to convert your existing soil into peat type soil by adding large amounts of organic matter. Some of the keenest exhibition growers do just this. It can be time-consuming and costly at first, but once you get their life becomes much easier. You must avoid making your soil too acid though, and careful choice of organic matter is needed.
Chalk soils and Limestone Soils
These are the soils that contain a high proportion of chalk or lime. So much in fact, that it overrides their normal particle size classification. They are often very shallow soils, and severely limit the types of plants that can be grown successfully in them. If you have a soil of this type and are not happy with the range of plants it will allow you to grow, probably the best thing you can do is move to a new area and check the soil out first. If you can’t move, the most sensible course of action is to limit yourself to the plants that will grow in chalky soils. Trying to change the soil is usually an uphill struggle and quite expensive. For the incurably intrepid, details are given later in the Golden Rules for Difficult Soils section.
If you wish to improve your soil, you must identify its characteristics, is it clay-based, chalky or sandy? You can find out all you need to know by simply working the soil you wish to grow in and information on local area soil types are easily available on the internet or your local library.
You can also test for the acidity or alkalinity of the soil with a soil testing kit that is widely available in garden centers.
Clay soil can be so compact that even in the middle of summer it can retain plenty of water, sandy soils are made up of larger particles and can warm-up and cool down very quickly. Chalky soil leaches water and nutrients very quickly and is a shallow stony soil. Loam is by far the best soil to grow in, it is very well balanced and does a very good job of retaining nutrients.
Sand Based Soils
This is a very light and easily worked soil, in the spring this soil warms up very quickly which gives the plants a good beginning to the season. However, they drain very well so nutrients are easily washed away, this is known as leaching. Sandy soils require lots of fertilizer or organic matter added to them.
Loam Based Soils
Loam is a rich and nutritious soil type that also holds water well; this is the soil type that is also used in sports like cricket and tennis. Loam is a mixture of sand and clay and is a particularly good soil to cultivate in as long as it does not become to compact.
Clay Based Soils
Clay is made up of particles that clog together and can become very compacted, although clay soils can become very rich, the compaction leads to a lack of air pockets in the soil which in turn leads to a lack of micro-organisms which break down organic matter into a form that can be uptaken by plants. To get the best out of clay soil, it is very important to work the soil to improve drainage and aeration.
Chalk Based Soils
Like sand-based soils, nutrients leach through this soil type very easily. In the high of summer and during periods of drought, excessive watering is needed. Alkaline loving plants thrive in chalk-based soils but acidic loving plants like azaleas do not do well at all.
Acidic and Alkaline Soils
The PH of soil is highly important, different plants require different amounts of elements and trace elements and the elements they can uptake is determined by the PH of the soil. The optimum PH for most plants is 6.5 PH, at this reading most elements are easily up-taken by a plant. Although towards the end of a season when plants flower of fruit, they often require PH levels to drop slightly. Acidic soils can be changed by adding lime which is available from most garden centers. Peat can be added to alkaline in soils to make it more acidic.
Living soil is a good soil which is rich in organic matter, this soil contains bacteria and micro-organisms which break down dead leaves and other organic matter into vital nutrients which plants can absorb.
The presence of earthworms is also a good sign as they aerate the types of soils and pull organic matter downwards which conditions the soil.
Working the ground with a spade or fork is a good way of aerating the waterlogged or compact soil, if done on a commercial basis machine can be used to do this.
Double digging bedding areas annually at the end of a season is a good way of ensuring good soil for the following year.
Adding organic materials like manure or compost will aerate the soil and improve its texture; this also helps to retain moisture so that plants can grow better. Compost is easily made and you can create it yourself from tea bags, old leaves, and vegetable peelings. Ideally, you want to create your own compost heap and leave it for about several months to break down. When it’s ready you will have a nice dressing for whatever requirements you need.
Types Soils Testing Kits
You can test soil PH balances with a simple soil testing kit. Simply add a small drop of the chemical to the types soils and it will produce a liquid that can be matched against the color chart provided with the testing kit. This will tell you the acidity or alkalinity of the types soils and also indicate the presence of key nutrients such as potassium, phosphorus, and nitrogen.
For more information watch this video:
Table of Contents
- 1 What are Different Types of Soil
- 2 What is Soil?
- 3 Types of soil
- 4 Characteristics of Different Soil Types
- 5 Soil Texture
- 6 Aerating Soil
- 7 Enriching Soil