Welcome to the North Carolina State University (NCSU) Program of Agronomy. In this program we will explain and answer questions about agronomy. We will also show some facts and real world problems based around Agronomy.

What is Agronomy?

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

Weathering Agents (Chemical and Mechanical)

Weathering is the breaking down of rocks, soil, and minerals.

Chemical Weathering is when the minerals in a rock change. The rock changes and becomes a different type of rock. Minerals that are stable deeper in the crust are not stable at the surface. Minerals that formed at higher temperatures and pressure change into minerals that are stable at the surface.

Mechanical Weathering breaks rocks into smaller pieces. the smaller rocks are the same as the bigger rocks, they are just smaller. The rock has broken but hasn't changed what type of rock it is. The smaller pieces have the same minerals in the same properties.


Soil Composition-Soil is a mixture of rock particles, minerals, decayed organic material, air, and water. Sand, silt, and clay make up the portion of weathered rock.

Soil Texture- Different amounts of varying sized particles make-up the inorganic part of soil. The percentage of each type of particle effects the characteristic of the soil. If the space between the particles are large enough and well connected, water flows through the soil more easily. Light soils, such as sand or silt drain water however heavier soils, such as clay tend to hold water. A loam is a soil with a combination of grain sizes.

Soil Horizon- Soil Horizon refers to the different layers of soil. The top layer, which is exposed the most to extreme conditions such as heat, cold, sun, wind, precipitation, receives the most weathering. This is also where fresh water comes into contact with the soil. As the water moves down through the layers, it is able to less work to change the soil.

Soil Formation

Soil formation requires weathering and it may take hundreds or thousands of years to create fertile soil.

Remote Sensing

What is Remote Sensing?

Remote sensing is the scanning of the earth by satellite or high flying aircraft in order to obtain information from a remote location.

How is it used to study humans impact on soil/earth?

Remote sensing is used to monitor and assist with natural resource management. Scientist can study land use, map wetlands, and chart wildlife habitats. They then use this information to minimize any damage to the environment by urban growth and create ways to best protect the earth's natural resources.

Why is soil important?

Soil supports life by providing a habitat for a wide range of organisms along with cleaning and holding our water. Soil influences the distribution of plant species which provide food for animals and help clean the air.

How is soil used?

-supports plant growth

-allows gas exchanges between land and air

-provides habitats for most of the organisms on earth

-holds and cleans water

-used to help create structures like roadbeds and buildings

What are the misuses of soil?

-over-farming which can deplete the soil of it's nutrients and minerals

-release of toxins/ pollutants

-over-forestation causing erosion

Soil Stewardship and advances in the field of Agronomy

As the world's population increases, so does the need for fresh, clean water and food. Governments and private companies are working together to learn how to use the earth's natural resources without depleting them. Agronomists are in the forefront as they continue to develop technologies to increase crop production, control pests and weeds, while protecting the environment. Agronomists are very important in issues of global concern, including food and water security, air quality, climate change, soil loss and degradation, health and nutrition, and many others.