Let's think about the "earth" not the planet, but rather the stuff we call dirt, or more kindly, soil.

Soil is actually a potent word. Somehow the word often implies a black crumbly textured material with an almost sweet aroma. Reality check - if we look around at our local "earth" we might hesitate to call it soil. It looks and feels more like dirt.

To a soil scientist it's all soil. By definition soil is any medium made of decomposed rock and/or organic matter, in which the roots of plants grow. It could be sandy, clayey or peaty, but it's all soil.

Imagine picking up a handful of "earth" and bringing it to a soils scientist. This seemingly simple soil is really amazingly complex. The soil scientist (using the U.S. system of soil taxonomy) will be able to classify your handful of soil as one of about 13,000 different kinds (series) of soils.

Basically soil is a mixture of parent material, organic material, air and water. The parent material comes from broken down rock. The organic material (humus) is broken down plant and animal remains.
Some soils are excellent for plant growth. These soils are fertile. Other soils are very poor for plant growth and will only support well adapted plant species.

Fertility could be considered the health of the soil. We all need to be aware of the importance of a healthy "earth" for the health of the entire planet. Soil conservation is critical. Let's not throw "earth" into the trash. We need to respect the dirt -mixed with a little compost it will become that black crumbly textured sweet smelling material we like to call soil.