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Agronomy Definition

the science of soil management and crop production.

Agronomy is the science and technology of producing and using plants for food, fuel, fiber, and land reclamation.

Careers for people who got a degree in agronomy include:

  • field researcher
  • lab researcher
  • sales (seeds, fertilizer or chemical)
  • technical representative
  • farm manager
Nature Is Speaking – Edward Norton is The Soil | Conservation International (CI)

Chemical VS. Mechanical


  • The erosion or disintegration of rocks

  • Caused by chemical reactions

  • Carbonation is a type of chemical weathering

  • Carbonation is the mixing of water with carbon dioxide to make carbonic acid


  • The process of breaking big rocks into little pieces

  • Process usually happens near the surface of the planet

  • The cool nights and hot days always cause things to expand and contract (that movement can cause rocks to crack and break apart)

Soil Facts

Soil Composition

  • complex mixture of different materials.
  • soil is a mixture of broken rocks and minerals, living organisms, decaying organic matter (humus), air and water
  • 45% of soil is made up of mineral particles
  • 25% is made up of air
  • 25% is made up of water
  • The last 5% of soil is made up of organic matter

*We have 1/2 of the amount of soil that we used to have about 1,000 years ago*

Soil Texture

The texture of soil is determined by the percentage of sand, silt, and clay. For example, the more clay and silt the smother the rock will be.

  • clay=soft
  • silt=soft
  • sand=grainy
  • gravel=bumpy/rough

Soil Horizons

A soil horizon is a layer generally parallel to the soil crust. The physical characteristics are different from the layers above and beneath. Each soil type usually has three or four horizons.

The main 4 layers are:

  • Topsoil (the layer on the top)
  • Subsoil (the second layer under the topsoil)
  • Humus (the third layer under the subsoil)
  • Bedrock (the layer on the bottom)
Bill Nye The Science Guy on Rocks & Soil (Full Clip)

Rate of Soil Formation

  • Soil formation requires weathering. The less weathering the soil is thinner. The more weathering the thicker the soil will be.
  • Soil forms at a rate of about 1mm/year. However it can depend on the climate and the rock type.
  • Soil forms quicker in hot and rainy areas. It forms slower in cold and dry areas.
Soil Formation

Remote Sensing

Remote Sensing

Remote sensing is the science of obtaining information about objects or areas from aircraft or satellites.

Remote sensors collects data by detecting the energy that is reflected from Earth.

One remote sensing is LIDAR (Light Detective and Ranging). This satellite uses lasers and it is used by farmers to fertilize our crops which could help our soils.

Remote sensing is best way to measure climate change, which is very important.

Importance of soil

Soils are essential for life. Soils provide minerals which plants need growth, habitat for many insects and other organisms, and filter surface water.

Soil is used for:

  • Soils support roots and keep them upright for growth.
  • Soils provide plants with essential minerals and nutrients.
  • Soils protect plants from erosion and other destructive physical, biological, and chemical activity.
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Common misuses of soil & The consequences

Some common misuses of soil are bad farming techniques like when you don't rotate your crops. Some farmers plant their crops along a hill which is bad because water could flow down the hill and the fertilizer could get into the creeks. Another misuse of soil is putting dangerous chemicals in the crops to make them grow bigger and faster but theses chemicals can hurt humans when we eat the crops. If farmers don't use the correct methods for farming, it can cause erosion.

Soil stewardship & Advances In Agronomy

To improve agronomy we need to minimize the amount of trees we cut down near river banks. We also need to alternate crops, so we can limit depleting minerals in soil. By using more compost and less chemicals we can improve our soils which helps with our overall environment.

We hope this information makes you want to help out and become an agronomist at NC State and help save our soil/earth.

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