North Carolina State University
Changing the world from the ground up
Chemical vs. Mechanical Weathering
Chemical weathering - process by which the internal structure of plants/vegetation is altered by the addition or removal of elements.
Soil Composition- While a nearly infinite variety of substances may be found in soils, they are categorized into four basic components: minerals, organic matter, air and water.
Soil texture is an important soil characteristic that influences storm water infiltration rates.
Rate Of Soil Formation
FACTORS AFFECTING SOIL FORMATION:
Parent Material- soil is formed from mineral or organic material
Time- Soil takes many years to form, some of the younger soils get characteristics from the older soils.
Climate- This is the most important factor in soil formation. The two most important key factors are temperature and precipitation. They both determine how quickly weathering will be and what kind of organic materials will be available.
Relief- This has to do with the landscape position and the angle it has. The greater the angle the greater potential for run off. The effect on soil will be poor if the angle is greater.
Organisms- Plants and animals on or within the soil have an effect on the richness of organic matter. Plants provide lots of vegetative residue that are added to soils. Their roots hold the soil together and they also provide shelter from the sun and other environmental conditions. Animals such as insects earthworms and fungi help the break down of organic material, aeration and mineral and nutrient cycle.
Information such as precipitation, wind and temperature extremes can be used to address any environmental concerns related to plants and vegetation.
Importance of soil
It influences the distribution of plant species and provides a habitat for a wide range of organisms.
Soil is used for plants,allows gas exchanges to happen between the land and air, and is also used for wildlife.It also holds and cleans water, and is used for constructing structures like buildings and roadbeds.
Common misuses of soil and the negative consequences
Crop yield has improved dramatically in the 20th century due to more sophisticated crop protection chemicals, genetic improvements, and genetic analysis.