![]() | Better Farming Series 02 - The Plant: the Stem; the Buds; the Leaves (FAO - INADES, 1976, 30 p.) |
![]() | ![]() | The leaves |
![]() | ![]() | What are leaves for? |
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To live, a man feeds and breathes.
To live, a plant also
feeds and breathes.
THE PLANT FEEDS
· The plant takes up food from
the soil through its roots. It takes water and mineral salts from the soil (see
Booklet No. 1, page 17). But it has to change the water and mineral salts.
A
baby drinks only milk. Its hair grows and so do its arms and legs.
It becomes
strong and heavy.
The baby has changed the milk in its stomach into hair,
fat, muscles, etc.
· The leaf changes the water and
mineral salts taken from the soil by the roots. Water and mineral salts make up
the raw sap (see Booklet No. 1, page 19, and Booklet No. 2, page 21 ).
The
leaf changes the raw sap into elaborated sap.
The leaf sends the elaborated
sap into the buds, flowers, fruits, stem and roots.
The elaborated sap feeds the whole plant.
· The leaf changes the raw sap into elaborated sap.
The elaborated sap FEEDS:
The elaborated sap
feeds
· The leaf feeds the
plant.
It receives the raw sap; it changes the raw sap into elaborated
sap.
This change is called plant material synthesis.
What is plant material synthesis?
· Heaps of sand, wood and bricks
are not a house.
To build a house you have to put them together.
You join
them with cement.
The cement changes the wood, sand and bricks into a house.
· Water and mineral salts cannot
feed the plant.
They have to be put together, they have to be joined.
How
are water and mineral salts joined together?
· The leaves live in the
air.
The air contains carbon dioxide gas.
The carbon dioxide gas is made
of oxygen and carbon.
The leaf keeps the carbon and gives off oxygen.
· The carbon joins the mineral
sale and the water.
The mineral salts and water are changed into elaborated
sap.
The elaborated sap can then feed the plant.
The carbon changes the
raw sap into elaborated sap.
This is plant material synthesis.
To join
sand, wood and bricks with cement requires work.
You can't have a house
without men's work, men's energy.
To join water and mineral salts with carbon
also requires work and energy.
· Light gives the leaf this energy.
Light enables the leaf to change raw sap into elaborated
sap.
At night there is no light, and the raw sap is not changed.
Light enables the leaf to change
raw sap into elaborated
sap
The plant gets water and mineral salts from the soil.
This is
inorganic matter.
This inorganic matter is changed by light and carbon and
becomes elaborated sap.
The elaborated sap feeds the plant.
Just as blood
enables a man to make his muscles, hair, bones, so elaborated sap enables a
plant to make leaves, wood, fruits. The leaves, the wood, the fruits are organic
matter.
Inorganic matter has become organic matter.
To live, a man feeds and breathes.
To live, a plant also
feeds and breathes.
A plant breathes through its
leaves.
When it is hot, a man sweats, he transpires.
A plant also
transpires.
The water in the sap evaporates, the leaf gets dry.
The plant
is
thirsty.