What is soil made of?

Soils can look like they are a homogeneous material. But in reality, soil contains solid particles of different sizes and different types. Some of the particles are minerals, and others are organic matter. There are spaces between the particles called pores. These pores may be filled with air or water. Soil is a mixture of … Continue reading What is soil made of?

Microbial respiration with iron

Most living creatures extract the energy in food through a process called respiration. During respiration, organisms take in oxygen and organic carbon (food) and breathe out water and carbon dioxide. Humans (and most creatures) require oxygen for respiration and therefore survival. But many microorganisms in soils do not need oxygen to survive! Unlike humans, soil … Continue reading Microbial respiration with iron

In general, what relationship does soil color bear to climate?

What is the first color that comes to mind when you envision soil? Is it brown, black, yellow, or red? How about white, gray, green, or blue? Any of these answers are correct depending on where you are from! It is true; soils come in an incredible range of colors. Complete soil profile, Maracai, Brazil, … Continue reading In general, what relationship does soil color bear to climate?