Plant Water and Soil
Date: April 2008
Hello I would like to know why does plants need water and
soil to keep them growing?
Like people, plants need water to live. They use it to carry food to all parts
of the leaves and stems. They need it to make their food. And they need it to
get rid of their waste.
Plants need soil for a lot of reasons. They need it for their roots. Why?
Because they drink, (that is take up water) using their roots. They also get
chemicals from the soil through their roots. They use these chemicals and
the water to grow bigger. And since plants cannot move by themselves the way
animals can, they need to have a place to stay, and the soil allows that.
Hope this answers your very good question.
Most plants need soil to keep their roots in place. The roots do two things.
First, they anchor the plant against wind. Second, they absorb the chemicals
that the plant needs to live. These two things are needed for the plants life.
Plants need water because water is part of the chemical reactions that plants
use to convert CO2 (carbon dioxide) into ingredients the plant needs to grow.
This process also requires light, so the name of this chemical process is
Not every kind of plant needs roots. Plankton, a kind of algae, which grows
in the ocean just floats around and hence no roots are needed.
A very good question - and a very important one if you are trying to grow plants.
Soil and water are a bit like the food and drink for the plant.
Water is very important, for two main reasons.
Firstly, it gives the plant a lot of its structure. Just as a balloon becomes firm
and rigid when you blow it up with air, so the tiny cells that make up the leaves
of the plant become firm and rigid when they are filled with water. If the water
is lost, because you forgot to water the plant, then the cells start to go soft,
just like the balloon would if you let the air out. What we see is that the leaves
become limp and soft, and we say the plant is wilting.
Secondly, the water allows the important changes to happen in the plant, because
chemicals (which come from the soil and the air) can travel around in the water.
Being able to move in the water is very important. If you put a dry teabag in your
mouth it has almost no taste. The chemicals which give the tea its flavour cannot
get to your tongue. But if you make the teabag wet you can taste the tea - and it
tastes even better when you use a cup and take the bag out after the favour is in
the water. In the plant, the water allows the various chemicals to work together
to build more cells so the plant can grow.
The soil is part of the plant's food.
Just like you, the plant needs food to grow. Unlike you, plants can make a lot of
their own food, because they can use sunlight to help them make food chemicals
called starches. This is a really important process. Without it, we would have no
food, because we get our starch from corn and potatoes and rice (all plants). The
process is called Photosynthesis. (we say FOE TOE SIN THU SIS ) and it works
because of the green colour in the leaves. The green is called Chlorophyl (Say CLAW
ROE FILL ) To be able to make chlorophyl and other parts of the leaves and so on,
the plant needs chemicals which it can only get from the soil.
And the soil also helps to hold the plant up. Plants and trees use the soil to hold
I apologise for the long explanation, and the big words, but you have asked a very
hard question, and I have tried to give you an answer which is accurate and easy to
understand - I hope I managed to do that.
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Update: June 2012