What Type of Soil do you have?
Soil is a gardener's most
precious resource and if well looked after it will produce bigger
crops and healthier plants that last longer. To ensure your soil
gives you the best results possible you need to understand it.
Soil is made up of two
layers, the topsoil and the subsoil.
The topsoil is the most
fertile and is generally a darker colour than the subsoil. Most of
the plants roots are in this layer, only the bigger roots reach down
to the subsoil.
Although the subsoil is
not as important as the topsoil it greatly affects how well plants
grow. Compacted subsoil means that roots can't penetrate and water
can often sit on the "pan" resulting in water logging. It is
sometimes necessary to break up the subsoil before beginning work on
the overall condition of the topsoil.
As most of the plants
roots are in the topsoil it is important to establish its
characteristics. The Soil Texture refers to the proportion of
particles making up the soil. There are three particles; clay, silt
and sand.
A high proportion of any
one of these particles determines the overall soil texture. A
mixture of all three results in loam which is the best soil to have.
There are advantages and disadvantages to all but loamy soils.
Soils high in clay tends
to drain slowly and becomes waterlogged making is difficult to work
and slow to warm up in spring. In summer it dries with a hard crust
making it very dry and liable to cracking. On the other hand it
retains nutrients so is the most fertile.
Sandy soils have large
particles and gaps which allow water and nutrients to quickly drain
away; but it is quick to warm up in spring.
Silty soils have fine
particles which bind together; this makes it difficult to work with
unless lots of organic matter is incorporated.
To determine the texture
of your soil carry out the following test.
Take a small amount of
soil and wet it. Knead lightly in the hand to form a smooth paste.
If it rolls easily and become shiny it is clay. If it feels gritty
and won't form a ball shape it is sand. If it feels sticky but
gritty and breaks up when rolled then its loam. As well as the three
main types there can be combinations such as a clay loam which will
roll easily but feels rough.
There is little you can
do to change the soil texture but there are plants to suit all
textures of soil, it is just a matter of working with it. However,
the soil structure can be changed.
Soil Structure is the
condition of the soil i.e. the combination of the particles and
organic matter forming the soil crumbs. For plants to thrive they
need a good balance of air and water, the introduction of organic
matter such as well rotted manure or leafmould, is beneficial to all
soil types. It will break up clay soil to improve drainage and will
bind together sandy soil to improve water retention.
You will also need to
consider your soil's pH which indicates the acidity of the soil.
Most plants will be quite happy in a Neutral or slightly acid or
alkaline soil with pH of between 6 and 8. If your soil is 7.5 or
more then your soil is alkaline, a pH of less than 7 means your soil
is acid and you will be able to grow plants such as Hydrangea and
Rhododendron. You can easily test the acidity of your soil by using
a simple Soil Testing Kit which are available from most garden
centres, just follow the instructions on the box.
The best way to improve
your garden soil is to increase the amount of humus it contains.
This can be done by either adding well-rotted organic matter or by
growing special green manures. Plants can also be given a boost by
applying fertilisers.
All soils can be improved
by adding well-rotted organic matter; but the effects depend on the
type of soil you have. On clay soil it aids drainage and aeration,
on sandy soil it helps retain moisture and boosts fertility and on
silty soil it helps prevent compaction.
Organic matter is best
applied either in autumn or spring. Now
let's get your soil ready.
|
