Without research and
the use of fertilizers, today's human population could
not survive. Limited amounts of nutrients in the soil
will be consumed by plants in just a few years. We need
to feed the soil with nutrients to be able to use it
again as farm land.
Nutrients for soil are
called fertilizers. These are what plants need to grow,
but what are the materials that plants need. How many
types of fertilizers exist? Where do they come from or
how are they made? Is any fertilizer good for any plant?