How many distinct layers make up a typical soil profile?

What percentage of Earth's soil contains approximately 45% minerals?

Which scientist first classified soils into different types in 1883?

What is the average depth of topsoil globally?

What percentage of Earth's total freshwater is stored in soil?

How long does it typically take for nature to form one inch of topsoil?

What percentage of soil organisms live in the top 3 inches of soil?

How many known soil types exist globally according to the FAO?

What is the optimal soil pH range for most plants?

How many microorganisms typically exist in one teaspoon of healthy soil?

What percentage of Earth's terrestrial biodiversity lives in soil?

How deep can plant roots typically grow in ideal soil conditions?

What percentage of soil should be air in ideal growing conditions?

How many earthworms can be found in one acre of healthy soil?

What is the average depth of the B horizon (subsoil) layer?

What percentage of organic matter should healthy agricultural soil contain?

How many pounds of living organisms exist in an acre of healthy soil?

What percentage of soil particles should be sand in loamy soil?

How many tons of soil per acre are lost annually to erosion globally?

What percentage of soil nutrients are cycled through earthworm activity?