NCSU Agronomy Department Flyer
for NCSU clollege day
Welcome
- Agronomy is the study of plants and soil and their environment.
- Agronomists focus on sustaining the world's food production, protecting the quality of the environment and conserving essential and important soil and water resources.
- They help make food better, just imagine people in poor places where children have to drink dirty water
- Dirty water could cause infections, and many other bad things.
- They also try many ways to improve food
- They also help take care of soil, you may be thinking now it's just soil, but guess what soil provides many things such as food which everybody needs
- As population keeps on increases, soil doesn't it usually decreases just think about that we need to take care of the soil we do have
Chemical and Mechanical Weathering
Chemical Weathering
What is chemical weathering?
Agents of Chemical weathering :
Some agents of Chemical Weathering are:
- Water-
Dissolves rock; ( most important cause )
- Carbon Dioxide -
Carbonic acid weathers softer rock
- Oxygen -
This process is Oxidation
- Living Organisms-
- Acid Rain-
Mechanical Weathering
What is Mechanical Weathering?
Agents of Mechanical Weathering:
- Release of pressure- causes top layers of the rock to crack and flake off
- Freezing and Thawing- water freezes causing the crack to get bigger
- Animal Actions- animals dig, this loosens the soil, and breaks apart rocks
- Plant Root Growth- roots grow in cracks in the rock breaking them apart
- Abrasion- sand in wind, water, ice or gravity can wear away rock
Soil Facts
Soil Composition
- Soil is important because it produces food and helps us in many other ways
- Good soil is supposed to have inorganic and organic materials
- Organic materials is stuff that is alive or used to be. This is called humus. Mixture of dead plants and animals
- Inorganic materials is non living stuff. In soil that would be sand, slit, and clay
- If soil does not at all have any organic material it will be like the sand in the desert
Soil Texture
Soil Horizons
Each layer lower is weathered just a little bit less than the layer above. Water flows through soil more easily if the spaces between the particles are large enough and well connected. Sandy or silty soils are light soils because they drain water. Clay particles allow only very small spaces between them, so clay-rich soils tend to hold water. Clay-rich soils are heavier and hold together more tightly.
Soil scientists measure the percentage of sand, silt, and clay in soil. They use this triangle to help. The triangle is shown below.
Soil Formation
How well soil forms and what type of soil forms depends on many factors. Theses include climate, original rock type, slope, amount of time, and biological activity.
Remote Sensing
Importance of soil
Soil is important for many reasons such as:
- it is an important resource, life on earth could not exist as it does today without soil
- the food that we eat depends entirely on soil
- if we don't have good soil then we won't have good fruits
- we all know we need water, but guess what soil filters and purifies water, so basically soil provides us with a lot of good and clean water
- They also purify the air around us
Common Misuses of soil and negative consequences
Common Misuses of soil are when:
- people remove a lot of vegetation
- when people log forests
- or prepare the land for farming or construction
- Even just walking or riding your bike over the same place can kill the grass.
One BIG negative consequence was the Dust Bowl.
The Dust Bowl
Soil Stewardship and advances
There have been many ways people have been trying to treat soil better. You could add organic material like manure or compost. This increases the soil's fertility. Increased fertility improves the soil's ability to hold water and nutrients. Planting nutrient rich cover crops helps the soil. Planting trees as windbreaks, plowing along contours of a field, or building terraces into steeper slopes all help to hold soil in place. Another technique is Crop Rotation. Crop Rotation is when farmers grow from each major plant family in different areas each year. They do this because of:
- pests and diseases
- avoiding soil nutrient depletion
- suppressing weeds
Another technique is farming around the contour which is when you are farming around the hill. So when the water is flowing down the hill, it gets stopped by all the rows. It's better than up and down the hills, where the water can follow your rows right down the hill. This helps prevent erosion on farms.
There are many ways that people have come up with to protect soil. These are just some of them.