Wednesday, April 12, 2023

The Earth’s Crust

Soil

Once rocks have been weathered into small enough sediments, soil can begin to form.

Soil – a mixture of: weathered rock (sediments)organic matter (living and dead material) mineralswaterand air.

Make up a memory sentence withactions and write it down in the blankprovided.

Rock is turned into sediment and mineral fragments by weathering but it is not considered soil until plants and animals live, die, and decay in it (e.g. leaves, insects, twigs, worms, bacteria, etc)

Compost – dead and decaying plant matter.

Compost mixed with rocks and mineral is called humus, which forms the dark coloured part of the soil which is very fertile.

Fertile soil – soil that provides nutrients for plant growth. We add fertilizers to soil to make sure it has all of the nutrients for plants to grow.

Plants need three nutrients to grow properly:

N - nitrogenP - phosphorusK - potassium)

Different bags have different amounts of N, P or K depending on what you need. If you put too much of any one of these chemicals in the soil, it could kill your plants.

On the side of a fertilizer bag you’ll see three numbers.

Example

15 - 5 – 5 N P K

Each number stands for how much nitrogen, phosphorus, or potassium the fertilizer has in it.

Soils can take thousands of years to form. They can range in thickness from 60 meters in some areas to just a few centimeters in others. Soil varies in structure and appearance, depending on its depth. These different layers of soil can be mapped to make a soil profile.

Soil profile – a picture of what the layers of soil look like underground.

Soil profiles will look different from area to area. You can make a soil profile by digging and exposing a vertical edge of the soil or you can drill a core sample using a soil sampler