Chapter One The Importance of Soil

 The history of Soil –Dates back all the way to the Egyptians civilization of 4,000 years ago –Recently in the US history supplies another example of soil misuse. This is with the Dust bowl of the 1930’s. –The Dust bowl was a drought that misused the soil in having wind erosion.

The Importance of Soil  Additional acreage is lost due to urbanization or degradation.  Soil is a nonrenewable resource

The Importance of Soil  Most of the time we take soil for granted.  Soil is a very thin and often fragile layer of life supporting material.

The Importance of Soil  Facts about the earth –Earth consists of solid part (core, mantle, and crust) and the atmosphere surrounding it. –Most of the earth is covered by sea –Where continents exist the crust is thicker –This is usually about 50 miles thick

The Importance of Soil  The atmosphere is about 170 miles deep.  The soil forms a very thin interface between the two.

The Importance of Soil  What does living things need? –Proper temperature –Oxygen –Water –Carbon –Other nutrients –These factors are exchanged in the soil that allow elements to be recycled rather than lost

The Importance of Soil  Oxygen: –Plant roots need oxygen to grow. –Gases will pass in and out of the soil to supply the oxygen for the roots

The Importance of Soil –Temperature  Plants will grow best in certain soil temperature ranges.  Most plants will root in temperature around degrees F.  Water: –Seldom stays in one place

The Importance of Soil  Carbon: –Plant leaves collect sunlight to use the energy in the process of photosynthesis. –Which involves converting atmosphere carbon to biological carbon –Atmosphere carbon = carbon dioxide –Biological carbon = simple sugars

The Importance of Soil  Nutrients : –Plant nutrients are chemicals a plant needs to grow. –There are two types of nutrients cycles  Nitrogen cycle  Mineral cycle

The Importance of Soil  Nitrogen: –Comes directly from the atmosphere where it occurs as a gas that plants cannot use.

4 Needs of Soil  There are four needs of the soil –Anchorage –Water –Oxygen –Nutrients

4 Needs of Soil  Anchorage: –This is where plants grow freely and are firmly supported or anchored so they can grow to reach the sunlight. –Water: –Soil will provide the plants with all the water the plant needs –Roots are the best water absorbing body.

4 Needs of Soil  Oxygen: –Call creature even plants need oxygen. Plants release oxygen during photosynthesis but consume it during respiration.

4 Needs of Soil  Nutrients: –There are 16 nutrients usually considered to be needed for plants. –Plants obtain 13 of the 16 nutrients from the soil itself. –Other nutrients come from Air and water.  Carbon  Oxygen  hydrogen

3 phase system  What is soil Matrix? –It is the arrangement of solid particles and pore spaces which consists of three phases of solid, liquid, and gases.

3 phase system  The ideal Soil Type: –50% solid material –45 % mineral particles –5% organic matter –25% water –25% gases

3 phase system  Root Growth: –Water reaches the root by two ways  either water flows toward the root  Or the root grows into moist soil

Ag Uses of Soil  Humans depend on soil to grow food, fiber, timber, and ornamental plants.  Most Ag uses require different soil types and management practices

4 Types of Ag Uses  1.Cropland: –Cropland is land which soil is worked and crops are planted, cared for, and harvested. –Crops that are grown  Annual crops are corn and soybeans  Fiber crops are cotton horticultural crops like vegetables.

4 Types of Ag Uses  Annual Crops: –Require yearly soil preparation –Perennial Forages: –Are alfalfa. –Which are crops that are in the ground for a few years –These crops keeps the soil completely cover and keeps the soil in place.

4 Types of Ag Uses  Perennial Hort. crops: –This includes fruits, nuts, and nursery stock

4 Types of Ag Uses  2.Grazing Land: –Much of the land in the US is grazed by cattle and sheep

4 Types of Ag Uses  3.Forest –Foresters probably disturb soil the least, –4. Other Uses –This usually deals with growing plants in tiny pots and usually with Landscapers

Non Ag Uses of Soil  A few of the Non Ag uses of soil are: –Recreation –Foundations –Waste Disposal –Building Materials

Non Ag Uses of Soil  Recreation: –Recreational uses of the soil can be:  Sitting in a urban park and seeing kids play on the playground, softball diamond,  They can also be golf courses, campgrounds.  Most demanding recreational use is the use of playing fields. As most of the time there is a demand to have good grow on turf that can with stand about anything.

Non Ag Uses of Soil  Foundations: –A good builder usually will have the soil tested to a dept of several feet. –The structural soundness of a building depends on the amount of soil that is under the building.

Land Uses in the US  27% is in rangeland  26% is in cropland  27% is in forestland  2% is in conservation reserve land  4% is in other land  6% is in urban land  8% is in pastureland