Today’s Objectives Describe different types of parent material. Identify factors involved in soil formation and development. Describe the process of soil formation

Soil Formation Discussion How do you think soil is created? What do you think soil is made from? What factors in nature do you think would affect the formation of soil?

Soil Formation – Transported Soils Transported Soil is soil that has been moved by natural processes. How is soil transported? Glacial Ice Wind Water Gravity Organic Deposits Volcanic Deposits Glaciers – Glacial Till in SW MN Wind – Snow Drifts Residual vs Transported – Which is more common

Factors Involved in Soil Formation The original source of most soils is bedrock which is broken down into smaller particles until it becomes soil. This process is called soil genesis. This rock is called parent material. Three types of rock: Igneous, Sedimentary and Metamorphic. Each type of rock gives unique characteristics to it’s soil.

Factors Involved in Soil Formation Topography refers to the slope characteristics of a soil. It includes the degree or steepness, length, shape, and direction of a slope. Topography affects: -Moisture -Erosion -

Factors Involved in Soil Formation Organisms that live in soil—like plants, insects, and microbes—actively affect soil formation. The greatest affect on the development of soil is from plants that once grew in it. This is referred to as native vegetation. It determines the kind and amount of organic matter in the soil. What do you think our area in SW Minnesota is?

Factors Involved in Soil Formation Time – Soil changes over time Weathering causes soil to: Mature—soil is at peak productivity with a high amount of organic matter. Water begins leaching away nutrients and plant growth starts to decline. This results in less organic matter. Aging happens faster in warm/humid climates Soil formation is a continuous process that takes thousands of years

Factors Involved in Soil Formation Climate refers to rainfall, freezing, thawing, wind, and sunlight. These factors are either directly or indirectly responsible for the breakdown of rocks and minerals, the release of plant nutrients, and many other processes affecting the development of soils. Precipitation and Temperature How do various climates affect soil formation?

Factors Involved in Soil Formation Humans – Cause change to happen rapidly How do humans affect soil and it’s development? How do humans change the soil in this area?