Soil The foundation for life!

How much soil is there?

Where does soil come from? Take out your notebook so we can define some terms we’ll hear in this video clip. 43B6-BA75-2B DC&blnFromSearch=1&productcode=DETB 43B6-BA75-2B DC&blnFromSearch=1&productcode=DETB Weathering Erosion

5 Factors that Influence Soil Formation Climate Soils form faster in warm wet climates. Organisms Earthworms and burrowing animals mix, aerate soil and add organic matter. Plants affect soil composition and structure. Topography Hills, valleys and exposure to sun, wind, water all influence how soil moves. Parent Material (rocks) Creates the minerals. Time It takes a long time to make soil and the four factors above change over time.

Soil Horizons These five factors work together to create a unique soil profile made of layers called horizons.

Soil Horizons O and A Soil layers form over time. These horizontal layers are called soil horizons. O horizon dark organic layer with leaves and grass. A horizon top soil with some organic matter mixed with minerals. Plants roots, bacteria, fungi, and small animals are abundant here, and plants thrive in it. It is generally the most productive layer of soil.

Soil Horizons B and C B horizon sub-soil that’s light in color most mineral leached from the topsoil accumulate here. C horizon This is a transition area between soil and parent material. on.com/index.cfm?guidAsset Id=a7fbe062-2c33-463b- a5f9-0396f63748e7 on.com/index.cfm?guidAsset Id=a7fbe062-2c33-463b- a5f9-0396f63748e7

Soil Composition Mineral Particles: sand, silt, clay Organic Matter Organisms Roots Humus (dark soil) Air Water d=8cc35bad-109d-4b0d-b6e3-fe3313ffcd20 d=8cc35bad-109d-4b0d-b6e3-fe3313ffcd20

Soil Structure

Soil Particles Sand – largest O20-40x Silt – medium o25x Clay – smallest.1 Pore space varies with size of particles

Sand Loose granular material. Forms from weathering of rocks. Particles are smaller than gravel but coarser than silt. Large size ( mm)

Silt Loose material like baby powder Primarily powered rock. Particles are smaller than sand but coarser than clay. Medium size (0.002 to 0.05 mm)

Clay Dense material and one of the most important because it can attract nutrients. Many different types. Made of very small particles (less than mm)

Sieves and Settling lab Sieves and settling are both measuring the same thing, the composition of the soil!

Soil Texture Courtesy USDA ?v=GWZwbVJCNec

Now you try!!! I will pair you up and you will receive a lab packet. Read through the packet and answer the questions in COMPLETE SENTENCES. I will assign you the lab I would like you to work on. Keep your lab sheet and I will collect the packets at the end of class. Be sure you leave enough time for your group to clean up.

Soils Watch this video and write down as many things as you can that relate to how soil is important to us. nt.html nt.html

Why is soil data important to scientists? Tells us specific information about how well the soil will perform as a filter of water and waste, as a home to organisms, as a location for plants that provide food and fibers as well as locations for buildings.

Ok, so we’ve learned… The major minerals that make up soil are: SAND SILT CLAY A combination of sand, silt and clay in almost equal amounts makes a LOAM soil Loam soil is the BEST soil for growing plants.

Soil Composition

Pore Space Pockets that fill with air or water in soil.

Air and Water Occupy the same pore space Essential for soil life

You decide… Sandy soil = Big, med or small pore spaces? Water goes through sand very quickly because of its large pore sizes. Silt soil = Big, med or small pore spaces? Water can be absorbed or trapped better in silt soil because it has smaller pore spaces. Clay soil = Big, med or small pore spaces? Water sits on clay because its pore sizes are to small for the water to drain through.

Soil Composition

Organic Matter Organic matter is matter that has come from a once-living organism. It is capable of decay, or the product of decay.

Decomposition (rotting) Decomposition is the break down of organic material into simpler forms of matter. This is a very important step in the nutrient cycle on our planet. There is only a finite amount of matter on our planet. This means it must get recycled, otherwise it would get used up! 2D68F237DEF D68F237DEF &first=0&FORM=LKVR5 2D68F237DEF D68F237DEF &first=0&FORM=LKVR5

Humus Humus is the dark rich soil remnants of decomposition. (a dark, spongy, jelly-like substance) It refers to any organic matter that has reached a point of stability, where it will break down no further and might, if conditions do not change, remain as it is for centuries, if not millennia.

Who are the decomposers? Not many people think much about them but they are VERY important! Decomposition is a critical ecosystem function that removes wastes, recycles nutrients, renews soil fertility and carbon capture/storage. action=view&current=decompsers.mp4

The decomposers are… Fungi (From the Kingdom Fungi) contains more than100,000 species (types). includes mushrooms, puffballs, truffles, morels, molds, yeasts and many others. Provides plants with nutrients and can cause disease. Provides animals with food, drugs and disease C-B589-35AA859DF4D1&blnFromSearch=1&productcode=DETB 455C-B589-35AA859DF4D1&blnFromSearch=1&productcode=DETB

Bacteria The smallest and simplest organisms. Single celled organisms. Can be found EVERYWHERE! More about them shortly! F15C6&blnFromSearch=1&productcode=DETB F15C6&blnFromSearch=1&productcode=DETB

A teaspoon of good farm soil contains up to 1 billion bacteria in more than 4,000 species.

Soil Organisms Bacteria in soil have sticky substance on cell wall. This “glue” holds soil particles to bacteria and to each other. This binds soil particles into larger particles. Fungi produce thread-like structures called mycelia which bind soil particles and peds making larger particles.

Ok so…. It is the combination of minerals (sand silt and clay), organic materials, and pore spaces that determine how well the soil can support plant life!

Soil Recipe Book