How does the depth at which a seed is planted affect its germintation?

Question

This is my science project topic question: for this can you give me any information on this? The different depths ares:

on top of the soil without covering them

just barely covering them with soil

.5 cm below surface

2 cm below surface

and lower than 2 cm

Can you give me any info/tips

Thanks in ADvance

Answer 1

Hi,

Plants have evolved over the eons to have seeds germinate best under specific conditions.  There are a number of things that might influence the germination of a plant's seed.

Some plants' seeds will rot if they are buried in soil, while others have a mechanism to coil the seed down into the ground.

The affect on a seed of its depth in the soil depends on the plant; more specifically, the plant's seed.

Some of the factors that may affect a seed's germination are:

1. Does the seed need some type of stimulus to start the germination process (some seeds must be scraped by rocks in a river; some must first pass through the digestive tract of an animal; and some must be burned in a fire before they will germinate)?

2. Does the seed require direct sunlight?

3. Does the seed require moisture from the ground?

4. Does the seed contain enough energy stored in it to push its new shoot up through the ground to the light?

5. Does the seed require open air to prevent rot?

These are just some of the factors.

If you have not thought of it already, you might want to experiment with a number of different plant seeds at the different depths you mentioned in your question to see what the differences are.  You might see one plant does best on the surface, while another plant does better buried below 2 cm.  (Look on the seed package or check with a person at the nursery to find plants with different recommended planting depths.)

I hope this is of some help to you.

Hiking Tony