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What to know about soil?


Soil is more than just dirt—its complex microgeography consists of a wide variety of interdependent living and nonliving components. The nonliving can be separated into organic (carbon-based) and mineral matter, each having different physical and chemical properties, but each serving vital roles in the soil’s proper functioning. The living encompasses micro- and macro- organisms which contribute to soil structure and unlock vital nutrients for plant consumption. The absence of matter, that is, empty space, is also a vital component of soil as it allows for water storage and root permeation. Therefore, the health of soil is dependent on a balance between soil chemistry, physics, and biology. Understanding this balance is key to understanding soil health.

Soil is important to our lives—our access to nutritious food, clean water and air, fuel, medicines, and protection from drought and flooding are all dependent on healthy soil. Soil may even be a key for tackling climate change. Thus, maintaining healthy soil is essential to maintain our way of life. So…

What makes soil healthy?

And what can we do to promote soil health?

Let’s dive into the science behind this crucial resource!

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Soil Physics
Full Soil Physics
Full Soil Physics

Soil Composition

The physical landscape of soil is a mixture of solids, liquids, and gas. About 50% of soil volume is solid, and the other 50% consists of pockets of air called pores that are either empty, filled with water, or filled with living organisms.

Figure 1: An example of the relative proportions of the components within a soil mixture.

The nonliving solids that make up soil consist of mineral matter (inorganic elements or compounds), and organic matter (carbon-containing compounds).

The proportions of water, pores, mineral & organic matter, and biota shown in the pie chart are a rough estimate of the general makeup of soil; these percentages vary from soil to soil and affect soil function. Here, we will discuss some of the most common physical parameters of healthy, productive soils – texture, structure, and porosity.

Full Soil Physics

Created by

Bria VarnBuhler Bria VarnBuhler avatar

Bria is a chemical biologist and educator with a curiosity for the microscopic and molecular workings of the world
Graduate Student
Weill Cornell Medicine
Math and Science Teacher
Greenwich Academy

Karl Palmquist Karl Palmquist avatar

Karl is a systems biologist interested in complexity, and an environmental advocate
Graduate Fellow
Rockefeller University
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