A worm burrows its way through the dark earth, ingesting particles of soil and expelling nutrient-rich casts in a constant forage for food. Charles Darwin described earthworms as one of the most ...

Favor dark soil that breaks apart easily and is rich with the scent of earth, and steer clear of sticky or foul-smelling ...

while a small proportion of the original carbon is retained in the soil through the formation of humus, a product that often gives carbon-rich soils their characteristic dark color (Fig.

So far, efforts to conserve and manage the earth's biological diversity have focused on the loss of above-ground species; reductions in soil biodiversity have gone by unnoticed. But as soil biota ...

Chalky soil is a light brown soil. Water drains through it quickly. Peat does not contain any rock particles. It's made from very old decayed plants and is dark, crumbly and rich in nutrients.

Thousands of years of prairie grass growth, death and decomposition have left a thick layer of dark, organic matter ... to form a nutrient-rich type of soil called loam. It gave Iowa one of ...